foreword

This soil survey contains information that can be used in land-planning programs in 

Yakima County Area. It contains predictions of soil behavior for selected land uses . The survey 

also highlights limitations and hazards inherent in the soil, improvements needed to overcome 

the limitations, and the impact of selected land uses on the environment. 

This soil survey is designed for many different users. Farmers, ranchers, foresters, and 

agronomists can use it to evaluate the potential of the soil and the management needed for 

maximum food and fiber production. Planners, community officials, engineers, 

developers, builders, and home buyers can use the survey to plan land use, select 

sites for construction, and identify special practices needed to insure proper performance. 

Conservationists, teachers, students, and specialists in recreation, wildlife 

management, waste disposal, and pollution control can use the survey to help them understand, 

protect, and enhance the environment. 

Great differences in soil properties can occur within short distances. Some soils are 

seasonally wet or subject to flooding. Some are shallow to bedrock. Some are too unstable to be 

used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic 

tank absorption fields. A high water table makes a soil poorly suited to basements or underground 

installations. 

These and many other soil properties that affect land use are described in this soil survey. 

Broad areas of soils are shown on the general soil map. The location of each soil is shown on 

the detailed soil maps. Each soil in the survey area is described. Information on specific uses is 

given for each soil. Help in using this publication and additional information are available at the 

local office of the Soil Conservation Service or the Cooperative Extension Service. 

 

Lynn A. Brown 

State Conservationist 

Soil Conservation Service 

This is a scanned version of the text of the original Soil Survey report of Yakima County Area, Washington issued May 1985. Original tables and 

maps were deleted. There may be references in the text that refer to a table that is not in this document. 

Updated tables were generated from the NRCS National Soil Information System (NASIS). The soil map data has been digitized and may include

 some updated information. These are available from http://soildatamart.nrcs.usda.gov.

 Please contact the State Soil Scientist, Natural Resources Conservation Service (formerly Soil Conservation Service) for additional 

 information.
Location of Yakima County Area in Washington. 
soil survey of 

Yakima County Area, Washington 

By Charles D. Lenfesty and Thomas E. Reedy, Soil Conservation Service 

Fieldwork by Charles D. Lenfesty, Thomas E. Reedy, Jonathan P. Edwards, 

James T. Bayer, Phillip S. Gale, Jack J. Rasmussen, Ronald A. Peyton, and Richard A. 

Pudney, Soil Conservation Service; and Thomas J. John, 

Washington State Department of Natural Resources 

United States Department of Agriculture, Soil Conservation Service, in 

cooperation with 

Washington State Department of Natural Resources; 

Washington State University, Agriculture Research Center; 

and United States Department of the Interior, Bureau of Indian 

Affairs 

YAKIMA COUNTY AREA is in the south-central part of 

Washington. It consists of privately owned land; land 

managed by the Forest Service, Bureau of Land 

Management, the Washington State Department of 

Game, and the Washington State Department of Natural 

Resources; and some Yakima Indian Reservation 

land. 

The survey area has a total land area of about 1,394 

square miles, or 892,136 acres. About 268,880 acres 

is irrigated cropland, 64,000 acres is nonirrigated 

cropland, 425,456 acres is rangeland, 133,800 acres 

is grazable woodland. Irrigated farming is the main 

economic enterprise in the area. The major crops include 

apples, cherries, hops, asparagus, corn, and grass and 

legumes grown for hay and pasture. 

About 65 different kinds of soil are in the survey area. 

The soils formed in alluvium, eolian sand, lake 

sediment, loess, and residuum derived from basalt 

and sandstone. Most of the soils are well drained; 

however, in some of the lower lying areas drainage is 

impeded and some of the soils are affected by excessive 

salts or alkali, or both. The soils are sandy to clayey in 

texture and are very shallow to very deep. In irrigated areas 

the soils are dominantly nearly level to strongly sloping. In 

nonirrigated areas the soils are dominantly 

moderately steep to steep. 

An older survey of Yakima County was published in 1958 

(19). It included most of the present survey area. The 

present survey updates the older survey and provides 

additional information and orthophoto maps that show the 

soils in greater detail. 

Descriptions, names, and delineations of soils in this soil 

survey do not fully agree with those on soil maps for 

adjacent counties. Differences are the result of better 

knowledge of soils, modifications in series concepts, 

intensity of mapping, or the extent of soils within the survey 

area. 

general nature of the survey area 

This section gives general information about the survey 

area. It discusses the history and development, 

physiography, geology, drainage and water supply, and 

climate. 

history and development 

Before the arrival of white settlers, the survey area was 

occupied by the seminomadic Yakima Indians (26). The 

land was used for camping, hunting, fishing, and gathering 

of food. As the area became settled, a Roman 
Catholic mission was established in the Ahtanum 

Valley in 1852 and irrigated farming was introduced. 

Yakima County was established in 1865. Raising livestock 

was the main economic activity until the Northern Pacific 

Transcontinental Railroad was extended into the area 

in 1886. Large investments were then made in irrigation to 

attract settlers. By 1900, with construction of the 

Sunnyside and Congdon Canal systems, Yakima 

Valley contained the largest irrigated acreage in 

Washington. The population in the county was centered 

around the market towns of Yakima, Union Gap, and 

Sunnyside. 

At present Yakima County is among the leading 

agricultural counties in the United States. It ranks first in the 

nation in the production of hops, apples, mint, peas for 

processing, honey, and several kinds of tree fruit. It is also a 

major center for the production of beef cattle. Also within the 

survey area are sheep operations, turkey farms, and dairy 

farms. 

physiography 

The central and eastern parts of the survey area are in the 

Walla Walla section of the Columbia Plateau physiographic 

province (10). These parts of the area are composed of five 

east-trending ridges formally named Umptanum, Yakima, and 

Rattlesnake Ridges; Cleman Mountain; and Horse Heaven 

Hills. In general, the ridges have even crests and smooth 

sides. Most are not forested and are used primarily as 

rangeland. The Horse Heaven Hills, in the southeastern part 

of the area, are predominantly used for nonirrigated 

crops, mainly winter wheat. Between the ridges are basin 

valleys that are tributary to the Yakima Valley. These include 

the Wenas, Naches, Moxee, and Ahtanum Valleys. 

These valleys are quite extensive and are the main areas 

used for irrigated crops. 

The place where the Yakima River flows between Ahtanum 

Ridge and Rattlesnake Ridge is known as Union Gap. It 

serves as a natural divide between the upper and the lower 

parts of Yakima Valley. The ridges and valleys, along with the 

lower lying foothills in the western part of the survey 

area, flank forested foothills and mountains in the far 

western part of the area. This part of the area is in the middle 

section of the Cascade Range. 

geology 

The geology of the survey area is quite varied. The 

mountainous areas in the western part consist of many 

different types of rock, including basalt and andesite. 

Representative soils that formed in loess mixed with 

material derived from basalt and in residuum and colluvium 

in these areas are those of the Jumpe, Sutkin, Sapkin, and 

Naxing series. The principal rock in the central and eastern 

parts is Yakima Basalt, which is the younger flow of 

Columbia River Basalt (7). This basalt 

originated from large fissures or rifts along which the fluid 

lava swelled to the surface and spread in all directions. Soils 

such as those in the Ritzville, Starbuck, Shano, and Bickleton 

series formed in areas where loess is underlain by basalt. 

Soils such as those in the Bakeoven, Lickskillet, Kiona, 

McDaniel, and Rock Creek series formed in colluvium and 

residuum derived from basalt. 

Overlying the Yakima Basalt in many areas that flank 

foothills and ridges are the light-colored tuffaceous 

sandstone, siltstone, and conglomerate of the Ellensburg 

Formation. This old stream-deposited sediment was derived 

from volcanic material ejected during the early development 

of the Cascade Range. The Formation occurs extensively in 

the Wenas Valley, in the lower reaches of the Naches Valley, 

in areas west of Yakima, and along the southern part of 

Rattlesnake Ridge. The Formation is more than 1,800 feet 

thick in places. Soils that formed in loess mixed with material 

derived from the Ellensburg Formation are those of the 

Harwood, Gorst, Cowiche, and Taneum series. 

Subsequent folding of the basalt has formed the series of 

east-trending ridges. The Ellensburg Formation was 

deposited during the early stages of basalt folding; therefore, 

it is on highly dissected terraces. The uplifting of these folds 

was so slow that the Yakima River was able to downcut 

rapidly enough to maintain its course. The tributaries to the 

Yakima River formed as a result of the basalt folding. In a 

few areas of the Wenas Valley and near Pamona, the 

Ellensburg Formation is capped by a late lava flow. 

The upper and lower parts of Yakima Valley have been 

filled with material that was deposited by normal stream 

activity and glacial outwash. These areas include low terraces 

and flood plains. Representative soils that formed in recent 

alluvium are those in the Esquatzel, Weirman, Ashue, Wenas, 

Toppenish, and Umapine series. Extensive areas in the lower 

part of Yakima Valley are mantled by loess underlain by lake 

sediment that was deposited during glacial flooding in the late 

Pleistocene. This sediment occurs at elevations of as much 

as 1,000 feet in the survey area. Warden soils are examples 

of soils that formed in loess overlying lake sediment. These 

are the most extensive soils in the survey area. 

drainage and water supply 

Almost all of the survey area drains into the Yakima 

River; however, the far northeastern and southeastern 

parts drain into the Columbia River. 

The supply of irrigation water comes primarily from streams 

that receive snowmelt from the Cascade Range. These 

streams have more than ample flow early in the growing 

season, but the flow decreases during the season. To 

supplement the flow of the streams in summer and fall, three 

large mountain lakes have been 
dammed to create storage reservoirs. These are the Cle Elum, 

Kachess, and Keechelus Lakes, which are in Kittitas County. 

Three other reservoirs, Tieton and Clear Lakes on the Tieton 

River and Bumping Lake on the Bumping River, are in 

Yakima County, and they greatly increase the flow of the 

Naches River. There is also a small reservoir in the Wenas 

Valley. Even with these reservoirs, there is frequently a 

shortage of water in tributaries of the Yakima River. 

Transmission losses and overirrigation aggravate the problems 

of water shortage, drainage, erosion, and alkali and salt 

accumulation. 

All available surface water presently is allocated to irrigated 

land. Development of more irrigated land will require additional 

storage capacity, more underground sources of water, or use of 

water-saving measures within present allocations. There 

appears to be potential for developing more irrigated land 

above the Roza Canal in the Moxee Valley and the south 

flanks of Rattlesnake Ridge. Other areas have little or no 

potential for irrigation because of the limited productivity of the 

soils and the high cost of obtaining water. 

climate 

Prepared by the National Climatic Center, Asheville, North 

Carolina. 

The Rocky Mountains partly shield the Yakima County 

Area from strong arctic winds, so winters, though cold, 

generally are not too severe. In summer Pacific Ocean winds 

are partially blocked; the days are hot, but the nights are fairly 

cool. Precipitation, except in mountainous areas, is scant in 

summer. In many places, however, it is adequate during the 

cooler parts of the year for growing nonirrigated small grain and 

range plants. The snowpack accumulation at high elevations 

supplies irrigation water for intensive farming in some of the 

lowland areas. 

Table 1 gives data on temperature and precipitation for the 

survey area as recorded at Yakima and Sunnyside in the 

period 1951-78 and at Rimrock in the period 1951-77. Table 

2 shows probable dates of the first freeze in fall and the last 

freeze in spring. Table 3 provides data on length of the growing 

season. 

In winter the average temperatures at Yakima, Rimrock, and 

Sunnyside are 32, 29, and 35 degrees F, respectively. The 

average daily minimum temperature is 23 degrees at Yakima, 

21 degrees at Rimrock, and 26 degrees at Sunnyside. The 

lowest temperature on record, which occurred at Yakima on 

February 1, 1956, at Rimrock on December 17, 1964, and at 

Sunnyside on January 26, 1957, is -20 degrees. In summer the 

average temperature is 68 degrees at Yakima, 61 degrees at 

Rimrock, and 70 degrees at Sunnyside. The 

average daily maximum temperature is about 82 degrees F. The 

highest recorded temperature, which occurred at Yakima on 

August 10, 1971, is 110 degrees. 

Growing degree days, shown in table 1, are equivalent to heat 

units. During the month, growing degree days 

accumulate by the amount that the average temperature each 

day exceeds a base temperature (40 degrees F). The 

temperature at which a crop ceases to grow varies, depending 

on the crop. A base temperature of 40 degrees has been 

arbitrarily chosen to typify the minimum temperature for some 

crops. The normal monthly accumulation is used to schedule 

single or successive plantings of a crop between the last freeze 

in spring and the first freeze in fall. 

The total annual precipitation is 7 to 8 inches at Yakima 

and Sunnyside and 25 inches at Rimrock. Of this, 30 percent 

at Yakima and Sunnyside and 20 percent at Rimrock usually 

falls in April through September, which includes the growing 

season for most crops. The heaviest 1-day rainfall recorded 

was 2.75 inches at Rimrock on November 20, 1962. 

Thunderstorms occur on about 7 days each year, and most 

occur in summer. 

The average seasonal snowfall is 25 inches at Yakima, 107 

inches at Rimrock, and 12 inches at Sunnyside. The greatest 

snow depth at any one time during the periods of record was 22 

inches at Yakima, 71 inches at Rimrock, and 11 inches at 

Sunnyside. On the average, 18 days at Yakima, 53 days at 

Rimrock, and 3 days at Sunnyside have at least 1 inch of snow on 

the ground, but the number of such days varies greatly from year 

to year. 

The average relative humidity in midafternoon is about 40 

percent. Humidity is higher at night, and the average at dawn is 

about 80 percent. The sun shines 75 percent of the time possible 

in summer and 30 percent in winter. The prevailing wind is from 

the west-northwest. Average windspeed is highest, 8 miles per 

hour, in spring. 

how this survey was made 

Soil scientists made this survey to learn what soils are in the 

survey area, where they are, and how they can be used. They 

observed the steepness, length, and shape of slopes; the size 

of streams and the general pattern of drainage; the kinds of 

native plants or crops; and the kinds of rock. They dug many 

holes to study soil profiles. A profile is the sequence of natural 

layers, or horizons, in a soil. It extends from the surface down 

into the parent material, which has been changed very little by 

leaching or by plant roots. 

The soil scientists recorded the characteristics of the 

profiles they studied and compared those profiles with others 

in nearby counties and in more distant places. They classified 

and named the soils according to nationwide uniform 

procedures. They drew the boundaries of the soils on aerial 

photographs. These photographs show trees, buildings, fields, 

roads, and other details that help in drawing boundaries 

accurately. The soil maps at the back of this publication were 

prepared from aerial photographs. 
The areas shown on a soil map are called map units. 

Most map units are made up of one kind of soil. Some are 

made up of two or more kinds. The map units in this survey 

area are described under "General soil map units" and 

"Detailed soil map units." 

While a soil survey is in progress, samples of some soils 

are taken for laboratory measurements and for engineering 

tests. All soils are field tested to determine their 

characteristics. Interpretations of those characteristics may 

be modified during the survey. Data are assembled from 

other sources, such as test results, records, field 

experience, and state and local specialists. 

For example, data on crop yields under defined 

management are assembled from farm records and from 

field or plot experiments on the same kinds of soil. 

But only part of a soil survey is done when the soils have 

been named, described, interpreted, and delineated on aerial 

photographs and when the laboratory data and other data 

have been assembled. The mass of detailed information 

then needs to be organized so that it can be used by 

farmers, rangeland and woodland managers, 

engineers, planners, developers and builders, home 

buyers, and others. 
general soil map units 

The general soil map at the back of this publication shows 

broad areas that have a distinctive pattern of soils, relief, and 

drainage. Each map unit on the general soil map is a unique 

natural landscape. Typically, a map unit consists of one or more 

major soils and some minor soils. It is named for the major soils. 

The soils making up one unit can occur in other units but in a 

different pattern. 

The general soil map can be used to compare the 

suitability of large areas for general land uses. Areas of suitable 

soils can be identified on the map. Likewise, areas where the 

soils are not suitable can be identified. 

Because of its small scale, the map is not suitable for 

planning the management of a farm or field or for selecting a 

site for a road or building or other structure. The soils in any 

one map unit differ from place to place in slope, depth, drainage, 

and other characteristics that affect management. 

The general soil map at the back of this survey does not join, 

in all instances, with the general soil maps for adjacent survey 

areas. Differences in the maps have resulted from 

differences in the occurrence of soil patterns, differences in 

the publication scale of the maps, and the recent advances in 

classification. 

The 13 map units in this survey have been grouped into four 

general kinds of landscape for broad interpretive purposes. 

Each of the broad groups and the map units in each group are 

described in the following pages. 

map unit descriptions 

soils on flood plains and terraces 

This group consists of four map units. It makes up about 24 

percent of the survey area. The soils in this group are nearly 

level to moderately steep. The native vegetation is mainly 

grasses, forbs, and shrubs. 

The soils in this group are very deep and somewhat 

excessively drained, well drained, somewhat poorly drained, 

and artificially drained. They formed in alluvium, eolian sand, 

and lacustrine sediment and have a mantle of loess or eolian 

sand. 

This group is used mainly for irrigated crops. It is also used for 

orchards, nonirrigated crops, rangeland, wildlife habitat, and 

homesites. 

1. Umapine-Wenas 

Very deep, somewhat poorly drained and artificially drained, 

nearly level and gently sloping soils; on flood plains 

This map unit is in the north-central and eastern parts of the 

survey area, along the Wenas, Ahtanum, and Yakima Rivers. 

Slope is 0 to 5 percent. The native vegetation is mainly waterand salt-tolerant grasses and forbs and salt-tolerant shrubs. 

Elevation is 650 to 1,800 feet. The average annual precipitation 

is 6 to 12 inches, the average annual air temperature is about 

50 degrees F, and the average frost-free season is 130 to 180 

days. 

This unit makes up about 3 percent of the survey area. It is 

about 40 percent Umapine soils and 10 percent Wenas soils. 

The remaining 50 percent is components of minor extent. 

Umapine soils are very deep and somewhat poorly 

drained. They formed in alluvium. These soils are silt loam 

throughout and are saline and alkaline. 

Wenas soils are very deep and artificially drained. They 

formed in alluvium. The surface layer is silt loam. The upper part 

of the subsoil is silt loam, and the lower part is silty clay loam. 

The upper part of the substratum is loam, and the lower part 

to a depth of 60 inches or more is loamy sand and gravelly 

loamy sand. 

Of minor extent in this unit are Fiander, Zillah, Toppenish, and 

Track soils and well drained Esquatzel soils. 

This unit is used mainly for irrigated crops. It is also used as 

rangeland, for wildlife habitat, and as homesites. 

This unit is suited to irrigated crops. The main limitation of 

the Wenas soils is wetness, and the main limitations of the 

Umapine soils are alkalinity and wetness. Where the Umapine 

soils are drained, leached of excessive salts, and irrigated, 

they are suited to such crops as sweet corn, alfalfa, winter 

wheat, and asparagus. 

The production of forage on this unit is limited by the salinity of 

the Umapine soils. 

This unit is well suited to habitat for wildlife such as 

upland game birds, waterfowl, wading birds, and numerous 

other birds and mammals. 
2. Weirman-Ashue 

Very deep, somewhat excessively drained and well 

drained, nearly level and gently sloping soils; on flood 

plains and low terraces 

This map unit is in the north-central part of the survey 

area, along the Yakima and Naches Rivers. Slope is 0 to 5 

percent. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 700 to 1,700 feet. The average annual 

precipitation is 7 to 14 inches, the average annual air 

temperature is about 51 degrees F, and the frost-free 

season is 130 to 180 days. 

This unit makes up about 4 percent of the survey area. It is 

about 50 percent Weirman soils and about 15 percent Ashue 

soils. The remaining 35 percent is components of minor 

extent. 

Weirman soils are on flood plains and low terraces that 

are dissected by flood channels in some places. These 

soils are very deep and somewhat excessively 

drained. They formed in mixed alluvium. The surface 

layer is sandy loam. The upper part of the underlying 

material is loamy fine sand, and the lower part to a depth 

of 60 inches or more is extremely gravelly sand. 

Ashue soils are on low terraces. They are very deep and 

well drained. They formed in alluvium. The surface 

layer is loam. The subsoil is very gravelly loam and 

very gravelly sandy clay loam. The substratum to a depth of 

60 inches or more is very gravelly sandy loam and extremely 

gravelly sand. 

This unit is used mainly for irrigated crops. It is also 

used for orchards, rangeland, wildlife habitat, and 

homesites. 

The main limitations of this unit for irrigated crops are the 

hazard of soil blowing and low available water capacity. 

Most crops need frequent applications of irrigation water; 

however, irrigation is not practical on the Weirman soils that 

have been channeled by frequent periods of flooding. 

Irrigated crops grown include corn, grain, grasses, legumes, 

and tree fruit. 

The production of forage on this unit is limited by low 

available water capacity and, on the Weirman soils, the 

hazard of flooding. 

This unit is well suited to habitat for wildlife such as 

upland game birds, waterfowl, wading birds, cavity-nesting 

birds, birds of prey, and a few deer. 

The main limitation for homesite development is the 

hazard of flooding on the Weirman soils. If the Ashue soils 

are used for septic tank absorption fields, seepage is a 

concern. 

3. Quincy-Hezel 

Very deep, somewhat excessively drained, nearly level to 

moderately steep soils, on terraces 

This map unit is in the eastern part of the survey area, in 

the vicinity of Sunnyside. Slope is 0 to 15 percent. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 650 to 1,100 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the frost-free 

season is 135 to 180 days. 

This unit makes up about 1 percent of the survey area. It 

is about 45 percent Quincy soils and 35 percent Hezel soils. 

The remaining 20 percent is components of minor extent. 

Quincy soils are very deep and somewhat excessively 

drained. They formed in eolian sand. These soils are loamy 

fine sand throughout. 

Hezel soils are very deep and somewhat excessively 

drained. They formed in lacustrine sediment and have a 

mantle of eolian sand. The surface layer is loamy fine sand. 

The underlying material to a depth of 60 inches or more is 

stratified loamy fine sand, very fine sandy loam, and silt 

loam. 

Of minor extent in this unit are well drained Cleman, 

Esquatzel, and Warden soils and poorly drained Wander 

soils. 

This unit is used mainly for irrigated field crops and 

orchards. It is also used as rangeland, for wildlife habitat, 

and as homesites. 

The main limitations of this unit for irrigated crops are the 

low available water capacity and the hazard of soil blowing, 

which makes tillage management important. Irrigated crops 

grown include grain, corn, and potatoes. Grasses and 

legumes are grown for hay, pasture, and seed. 

The production of forage on this unit is limited by low 

available water capacity. 

This unit provides habitat for some game birds such as 

pheasant, dove, and quail. 

The main limitation of this unit for homesite development 

is the hazard of soil blowing during construction. 

Construction sites should be disturbed as little as possible. 

The Hezel soils are moderately slowly permeable, which 

affects the rate of absorption of effluent from septic tank 

absorption fields. If the density of housing is moderate to 

high, community sewage systems are needed on the 

Quincy soils to prevent contamination of water supplies as a 

result of seepage from septic tank absorption fields. 

4. Warden-Esquatzel 

Very deep, well drained, nearly level to moderately steep 

soils; on terraces and flood plains 

This map unit is in the east-central part of the survey 

area, east of Yakima and in the vicinity of Moxee. Slope is 

0 to 30 percent. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 600 to 1,500 feet. The 

average annual precipitation is 6 to 10 inches, the average 

annual air temperature is about 50 degrees F, and the 

frost-free season is 135 to 180 days. 

This unit makes up about 16 percent of the survey 

area. It is about 60 percent Warden soils and about 20 
percent Esquatzel soils. The remaining 20 

percent is components of minor extent. 

Warden soils are on terraces. These soils are very 

deep and well drained. They formed in lacustrine 

sediment and have a mantle of loess. The surface layer and 

subsoil are silt loam. The substratum to a depth of 60 inches 

or more is stratified silt loam and very fine sandy loam. 

Esquatzel soils are on flood plains. These soils are 

very deep and well drained. They formed in silty 

alluvium. These soils are silt loam throughout. 

Of minor extent in this unit are Burke, Cleman, Finley, 

Ritzville, Scion, Smoothened, and Shano soils. Also 

included are somewhat poorly drained Outlook and Sin loc 

soils and somewhat excessively drained Quincy soils. 

This unit is used mainly for irrigated crops. It is also used 

for orchards, nonirrigated crops, rangeland, wildlife habitat, 

and homesites. 

The main limitation of this unit for irrigated crops is the 

hazard of soil blowing. Proper irrigation water management 

is needed to prevent overirrigation and subsequent 

development of saline and alkaline seeps. A wide 

variety of irrigated crops can be grown, including asparagus, 

corn, grain, grapes, hops, mint, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitations for nonirrigated crops are the low 

annual precipitation and the hazards of soil blowing and 

water erosion. The soil in this unit generally is too dry for 

annual cropping; however, it is well suited to the production of 

winter wheat if a summer fallow cropping system is used. 

The production of forage on this unit is limited by the 

low annual precipitation. Proper grazing use combined with 

a deferred-rotation grazing system is the most 

effective and least expensive method of range 

improvement. 

This unit is suited to habitat for game birds such as 

dove, pheasant, and quail. 

The main limitations of this unit for homesite development 

are the hazard of flooding on the Esquatzel soils and the 

areas of the Warden soils that have slopes of more than 15 

percent. If these areas are used for septic tank absorption 

fields, slope may cause lateral seepage and surfacing of 

effluent in down slope areas. 

soils on high dissected terraces 

This group consists of one map unit. It makes up about 8 

percent of the survey area. The soils in this group are 

nearly level to steep. The native vegetation is mainly 

grasses, forbs, and shrubs. 

The soils in this group are shallow and moderately deep 

and are well drained. They formed in loess and old alluvium 

and are underlain by a lime- and silica cemented pan in 

some areas. 

This group is used mainly for irrigated field and 

orchard crops. It is also used for nonirrigated crops, 

rangeland, wildlife habitat, and homesites. 

5. Harwood-Gorst-Selah 

Moderately deep and shallow, well drained, nearly level to 

steep soils; on high dissected terraces 

This map unit is in the central part of the survey area, 

west of Selah and Yakima, north of the Wenas Valley, and 

along the south flanks of Rattlesnake Ridge. Slope is 0 to 

60 percent The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 1,100 to 2,000 feet. The average 

annual precipitation is 8 to 12 inches, the average annual 

air temperature is about 51 degrees F, and the frost-free 

season is 135 to 180 days. 

This unit makes up about 8 percent of the survey area. It 

is about 35 percent Harwood soils, 20 percent Gorst soils, 

and 10 percent Selah soils. The remaining 35 percent is 

components of minor extent. 

Harwood soils are moderately deep and well drained. They 

formed in loess and old alluvium. The surface layer and 

subsoil are loam. The substratum is gravelly loam. A 

cemented pan is at a depth of about 30 inches. 

Gorst soils are shallow and well drained. They formed in 

loess and old alluvium. These soils are loam. A cemented 

pan is at a depth of about 15 inches. 

Selah soils are moderately deep and well drained. They 

formed in loess and old alluvium. The surface layer and the 

upper part of the subsoil are silt loam. The lower part of the 

subsoil is silty clay loam or clay loam. A lime- and silicacemented pan is at a depth of about 34 inches. 

Of minor extent in this unit are Cowiche, Esquatzel, 

Gorskel, Logy, Ritzville, Rock Creek, Roza, Selah, 

and Willis soils. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. 

The main limitation of this unit for irrigated crops is depth 

to the cemented pan in the Gorst soils. Soil depth and 

steepness of slope make irrigation water management 

important. The Gorst soils are suited to permanent crops 

such as grasses and legumes and to orchards with perennial 

cover crops. The Harwood soils are suited to orchards and 

to crops such as corn, grain, grapes, peas, grasses, and 

legumes. The Selah soils are suited to orchards and to 

crops such as grain, grasses, and legumes. 

The Harwood soils are suited to nonirrigated crops such as 

winter wheat if a summer fallow cropping system is used. 

The production of forage on this unit is limited by low 

available water capacity and low annual 

precipitation. Proper grazing use combined with a 

deferred-rotation grazing system is the most effective and 

least expensive method of range management. 
This unit is suited to habitat for game birds, including 

dove, pheasant, and quail. 

The main limitations of this unit for use as homesites are 

depth to the cemented pan of the Gorst soils and the areas 

that have slopes of more than 15 percent. The pan hinders 

excavation. If the unit is used for septic tank absorption 

fields, slope can cause lateral seepage and surfacing of 

effluent in downslope areas. 

soils on uplands, ridgetops, and plateaus 

This group consists of six map units. It makes up about 

45 percent of the survey area. The soils in this group are 

nearly level to steep. The native vegetation is mainly 

grasses, forbs, and shrubs. 

The soils in this group are very shallow to very deep and 

are well drained. They formed in loess, in residuum and 

colluvium derived from basalt, andesite, or sandstone, and 

in material derived from fine-textured sediment. 

This group is used mainly for nonirrigated crops and as 

rangeland. It is also used for irrigated field and orchard 

crops, irrigated hay and pasture, wildlife habitat, and 

homesites. 

6. Lickskillet-Starbuck 

Shallow, well drained, nearly level to steep soils; on 

uplands 

This map unit is in the northeastern part of the survey 

area, on Rattlesnake and Yakima Ridges, and along the 

eastern part of the area, near Byron. Slope is 0 to 60 

percent. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 700 to 3,200 feet. The 

average annual precipitation is 6 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the frostfree season is 120 to 170 days. 

This unit makes up about 9 percent of the survey area. It is 

about 35 percent Lickskillet soils and 15 percent Starbuck 

soils. The remaining 50 percent is components of minor 

extent. 

Lickskillet soils formed in loess and in residuum and 

colluvium derived from basalt. The surface layer is silt loam 

or very stony silt loam. The subsoil is very gravelly silt loam, 

very gravelly loam, or very cobbly loam. Basalt is at a depth 

of about 20 inches. Depth to basalt ranges from 12 to 20 

inches. 

Starbuck soils formed in loess. The surface layer and the 

upper part of the subsoil are silt loam. The lower part of the 

subsoil is gravelly silt loam. Basalt is at a depth of about 16 

inches. Depth to basalt ranges from 12 to 20 inches. 

Of minor extent in this unit are Bakeoven, Bickleton, 

Cowiche, Esquatzel, Harwood, Kiona, Moxee, Renslow, 

Ritzville, Selah, Simcoe, and Willis soils and Rock outcrop. 

This unit is used mainly as rangeland. It is also used for 

irrigated crops, for wildlife habitat, and as homesites. 

The production of forage on this unit is limited by low 

available water capacity and low annual precipitation. 

The main limitations of this unit for irrigated crops are the 

shallow depth to bedrock and steepness of slope, which 

make proper irrigation water management important. 

This unit is well suited to habitat for game birds such as 

chukar and quail and for deer and bighorn sheep. 

The main limitations of this unit for homesite 

development are the shallow depth to rock and the areas 

that have slopes of more than 15 percent. The rock hinders 

excavation. If this unit is used for septic tank absorption 

fields, the shallow depth to rock limits the absorption 

capacity of the soils and slope can cause lateral seepage 

and surfacing of effluent in downslope areas. 

7. Willis-Moxee 

Moderately deep and shallow, well drained, nearly level to 

moderately steep soils; on uplands 

This map unit is in the northeastern part of the survey 

area, along the southern flanks of Yakima and Rattlesnake 

Ridges. Slope is 0 to 30 percent. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,200 to 2,500 

feet. The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 49 degrees F, and 

the frost-free season is 125 to 160 days. 

This unit makes up about 8 percent of the survey area. It 

is about 35 percent Willis soils and 15 percent Moxee soils. 

The remaining 50 percent is components of minor extent. 

Willis soils are moderately deep and well drained. They 

formed in loess. The surface layer is fine sandy loam or silt 

loam. The subsoil and substratum are silt loam. A lime- and 

silica-cemented pan is at a depth of about 34 inches. Depth 

to the pan ranges from 20 to 40 inches. 

Moxee soils are shallow and well drained. They formed 

in loess. The surface layer and subsoil are silt loam. The 

substratum is gravelly silt loam. A lime- and silicacemented pan is at a depth of about 18 inches. Depth to 

the pan ranges from 10 to 20 inches. 

Of minor extent in this unit are Cowiche, Finley, 

Ritzville, Scooteney, and Starbuck soils. 

This unit is used for irrigated crops, irrigated hay and 

pasture, nonirrigated crops, rangeland, wildlife habitat, and 

homesites. 

The main limitation of this unit for irrigated crops are depth 

to a cemented pan and steepness of slope, which make 

irrigation water management important. The Moxee soils are 

suited to permanent crops such as grasses and legumes and 

to orchards with perennial cover crops. The Willis soils are 

suited to orchards and to crops such as corn, grain, 

grapes, peas, grasses, and legumes. 
The main limitations of this unit for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. The Willis 

soils are suited to the production of winter wheat if a summer 

fallow cropping system is used. 

The production of forage is limited by low annual precipitation 

and low available water capacity. Proper grazing use along with a 

deferred-rotation grazing system is the most effective and least 

expensive method of range management. 

This unit is suited to habitat for game birds such as dove, 

pheasant, and quail. 

The main limitations of this unit for use as homesites are depth 

to the cemented pan and the areas that have slopes of more 

than 15 percent. The pan hinders excavation. The shallow and 

moderate depth of the soils in this unit limits the capacity of 

septic tank absorption fields. Slope can cause lateral seepage 

and surfacing of effluent in downslope areas. 

8. Ritzville-Starbuck 

Very deep, deep, and shallow, well drained, nearly level to 

steep soils; on uplands 

The map unit is mainly on Horse Heaven Hills and in Moxee 

Valley. A few areas of the unit are west of Yakima, west of 

Selah, and on the northwestern end of Rattlesnake Ridge. 

Slope is 0 to 60 percent. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 700 to 2,500 feet. The 

average annual precipitation is 6 to 12 inches, the average annual 

air temperature is about 49 degrees F, and the frost- free 

season is 130 to 170 days. 

This unit makes up about 12 percent of the survey area. It is 

about 75 percent Ritzville soils and 10 percent Starbuck soils. 

The remaining 15 percent is components of minor extent. 

Ritzville soils are deep and very deep and are well drained. 

They formed in loess. The soils are silt loam to a depth of 60 

inches or more. 

Starbuck soils are shallow and well drained. They formed in 

loess. The surface layer and the upper part of the subsoil are 

silt loam. The lower part of the subsoil is gravelly silt loam. Basalt 

is at a depth of about 16 inches. Depth to basalt ranges from 12 

to 20 inches. 

Of minor extent in this unit are Bickleton, Cowiche, 

Esquatzel, Kiona, Renslow, Selah, and Willis soils and 

Rock outcrop. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and homesites. 

The main limitations of this unit for irrigated crops are depth to 

rock in the Starbuck soils and a hazard of water erosion. Depth to 

rock and steepness of slope make irrigation water management 

important. The Starbuck soils generally are suited to permanent 

crops such as grasses and legumes and to orchards with cover 

crops. Crops commonly grown on the Ritzville soils include 

grain, corn, grapes, hops, mint, peas, and tree fruit. Grasses 

and legumes are grown for hay, pasture, and seed. 

The main limitation of the Ritzville soils for use as nonirrigated 

cropland is low annual precipitation. These soils are well suited 

to the production of winter wheat if a summer fallow cropping 

system is used. Starbuck soils are not used for nonirrigated 

crops. 

The production of forage on the Starbuck soils is limited by low 

available water capacity. The Ritzville soils are well suited to the 

production of forage. 

This unit provides habitat for game birds such as 

pheasant, quail, and dove. 

The main limitation of the Starbuck soils for use as homesites 

is depth to rock, which hinders excavation. The Ritzville soils 

have few limitations. If the soils in this unit are used for septic 

tank absorption fields, steepness of slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

9. Taneum-Tieton 

Deep and very deep, well drained, nearly level to steep, moist 

soils; on uplands 

This map unit is in the northern part of the Wenas Valley and in 

the vicinity of Tieton and Cowiche. Slope is 0 to 60 percent. The 

native vegetation is mainly grasses, forbs, and shrubs. Elevation 

is 1,500 to 3,000 feet. The average annual air temperature is 

about 49 degrees F, the average annual precipitation is 11 to 18 

inches, and the frost-free season is 120 to 150 days. 

This unit makes up about 4 percent of the survey area. It is 

about 40 percent Taneum soils and 40 percent Tieton soils. 

The remaining 20 percent is components of minor extent. 

Taneum soils are very deep and well drained. They 

formed in loess overlying weathered sandstone. The 

surface layer is loam. The subsoil is silty clay loam or clay 

loam. The substratum to a depth of 60 inches or more is 

loam or sandy loam. 

Tieton soils are deep and well drained. They formed in loess 

and in material weathered from andesite. The surface layer is 

fine sandy loam or loam. The subsoil is loam, silty clay loam, or 

clay loam. The substratum is loam. Weathered andesite is at a 

depth of about 50 inches. Depth to andesite ranges from 40 to 

60 inches. 

Of minor extent in this unit are Clint, Esquatzel, Logy, 

McDaniel, Meystre, Rock Creek, and Roza soils. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and homesites. 

The Tieton soils are suited to irrigated crops. The main 

limitations are a hazard of soil blowing in areas that have a fine 

sandy loam surface layer and a hazard of water erosion in 

areas that have a loam surface layer. Crops grown include tree 

fruit, grain, and grapes. Grasses and legumes are also grown 

for hay and pasture. The main 
limitation of the soils for growing tree fruit is the length of 

the growing season. The Taneum soils generally are 

not irrigated. 

This unit is suited to nonirrigated crops. The main 

limitation is low annual precipitation. The soils in this unit are 

suited to the production of winter wheat in rotation with 

summer fallow and spring barley. 

This unit is well suited to use as rangeland. Most of the 

areas of rangeland are on the Taneum soils. 

This unit is well suited to habitat for game birds such as 

pheasant, quail, and dove and for deer and elk. 

The main limitations of this unit for use as homesites are 

shrink-swell potential and the areas that have slopes of 

more than 15 percent. If the unit is used for septic tank 

absorption fields, slope can cause lateral seepage and 

surfacing of effluent in downslope areas. 

10. Rock Creek-McDaniel 

Very shallow and very deep, well drained, nearly level to 

steep soils, on plateaus and ridgetops on uplands 

This unit is in the northwestern part of the survey area. 

Slope is 0 to 65 percent. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 1,200 to 3,300 

feet. The average annual precipitation is 12 to 18 inches, the 

average annual air temperature is about 49 degrees 

F, and the frost-free season is 120 to 170 days. 

This unit makes up about 9 percent of the survey area. It 

is about 55 percent Rock Creek soils and 20 percent 

McDaniel soils. The remaining 25 percent is components of 

minor extent. 

Rock Creek soils are on plateaus and ridgetops on 

uplands. These soils are very shallow and well 

drained. They formed in loess and in residuum derived 

from basalt. The surface layer is very stony silt loam. The 

subsoil is very cobbly clay. Basalt is at a depth of about 10 

inches. Depth to basalt ranges from 8 to 15 inches. 

McDaniel soils are on uplands. These soils are very deep 

and well drained. They formed in loess and in colluvium 

derived from basalt. The surface layer is very stony 

loam. The underlying material to a depth of 60 inches or 

more is very gravelly clay loam, very cobbly silty clay loam, 

or extremely cobbly silty clay loam. 

Of minor extent in this unit are Clint, Esquatzel, Logy, 

Meystre, Roza, and Taneum soils. 

This unit is used as rangeland, for wildlife habitat, and as 

homesites. 

The production of forage on the Rock Creek soils is 

limited by low available water capacity. The McDaniel soils 

are well suited to use as rangeland. Seeding is difficult 

because of stones on the surface. Proper grazing use and 

periodic rest of areas of rangeland are the most effective and 

least expensive methods of range management and erosion 

control. 

This unit is well suited to habitat for deer, elk, bighorn 

sheep, and game birds such as chukar and pheasant. 

The main limitations for homesites on the Rock Creek 

soils are the very shallow depth to bedrock, large 

stones, and the areas that have slopes of more than 15 

percent. The bedrock hinders excavation. The presence of 

large stones can interfere with the operation of equipment 

and the installation of absorption lines. The McDaniel soils 

generally are not used as homesites. 

11. Cowiche-Roza 

Very deep, well drained, nearly level to steep soils; on 

uplands 

This map unit is in the north-central part of the survey 

area, on the north and south sides of the Wenas Valley and 

northwest of Selah. Slope is 2 to 60 percent. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

1,000 to 2,000 feet. The average annual air temperature is 

about 50 degrees F, the average annual precipitation is 8 to 

12 inches, and the frost-free season is 135 to 160 days. 

This unit makes up about 3 percent of the survey area. It 

is about 40 percent Cowiche soils and 35 percent Roza 

soils. The remaining 25 percent is components of minor 

extent. 

Cowiche soils formed in residuum derived from sandstone 

and have a mantle of loess. The surface layer and subsoil 

are loam. The upper part of the substratum is very fine sandy 

loam, and the lower part to a depth of 60 inches or more is 

loamy fine sand. 

Roza soils formed in material derived from fine-textured 

sediment. The surface layer is clay loam. The subsoil is 

clay loam or silty clay. The substratum to a depth of 60 

inches or more is silty clay, silty clay loam, or clay loam. 

Of minor extent in this unit are Cleman, Gorst, 

Harwood, Logy, Rock Creek, and Taneum soils and 

Torriorthents. 

This unit is used mainly as rangeland and for wildlife 

habitat. Some areas are used for irrigated and nonirrigated 

crops and as homesites. 

This unit is suited to use as rangeland. Proper grazing use 

and periodic rest of the areas of rangeland are the most 

effective methods of range management and erosion 

control. Range seeding is a suitable practice if the range 

vegetation is in poor condition. 

This unit is suited to habitat for game birds such as 

chukar, quail, and pheasant and for deer and elk. 

The main limitations of this unit for irrigated crops are 

steepness of slope, a hazard of water erosion on the 

Cowiche soils, and the slow permeability of the Roza soils. 

Proper irrigation water management is needed to prevent 

overirrigation and reduce the risk of water erosion. 

Applications of irrigation water should be adjusted to the 

slow permeability of the Roza soils. 

The Cowiche soils are suited to nonirrigated crops. The 

average annual precipitation is too low for annual cropping; 

however, the soils are suited to the production of winter 

wheat if a summer fallow cropping system is used. 
The main limitations of this unit for use as homesites are the 

shrink-swell potential and slow permeability of the Roza soils. 

If the unit is used for septic tank absorption fields, 

steepness of slope in places can cause lateral seepage 

and surfacing of effluent in downslope areas. 

soils on uplands and mountains and in 

canyons 

This group consists of two map units. It makes up about 23 

percent of the survey area. The soils in this group are nearly 

level to very steep. The native vegetation is mainly conifers, 

grasses, forbs, and shrubs. 

The soils in this group are moderately deep and very deep 

and are well drained. They formed in residuum and colluvium 

derived from basalt and containing loess and volcanic ash. 

This group is used mainly as grazable woodland and 

rangeland and for wildlife habitat. 

12. Jumpe-Sutkin-Sapkin 

Very deep and moderately deep, well drained, nearly level to 

very steep soils; on uplands, mountainsides, and smooth 

mountaintops, in canyons, and on long, broad ridges 

This map unit is in the western part of the survey area. Slope is 

0 to 75 percent. The native vegetation is mainly conifers, 

grasses, forbs, and shrubs. Elevation is 2,400 to 5,800 feet. 

The average annual precipitation is 18 to 40 inches, the average 

annual air temperature is about 43 degrees F, and the average 

frost-free season is 95 to 130 days. 

This unit makes up about 18 percent of the survey area. It is 

about 35 percent Jumpe soils, 20 percent Sutkin soils, and 20 

percent Sapkin soils. The remaining 25 percent is 

components of minor extent. 

Jumpe soils are on mountainsides, on long, broad ridges, 

and in canyons. These soils are very deep and well drained. 

They formed in residuum and colluvium derived from basalt 

and containing a minor amount of loess and volcanic ash. The 

surface layer is stony loam. The subsoil and substratum to a 

depth of 60 inches or more are extremely cobbly loam. 

Sutkin soils are on mountainsides and in canyons. They are 

very deep and well drained. They formed in colluvium and 

residuum derived from basalt and containing a minor amount of 

loess. The surface layer is stony loam. The subsoil is very cobbly 

loam or extremely cobbly loam. The substratum to a depth of 60 

inches or more is cobbly loam. 

Sapkin soils are on uplands and mountainsides. These soils 

are moderately deep and well drained. They formed in 

colluvium and residuum derived from basalt and containing a 

minor amount of loess. The surface layer is very stony loam or 

loam. The subsoil is cobbly loam, very cobbly loam, or 

extremely cobbly clay loam. Basalt 

is at a depth of about 27 inches. Depth to basalt ranges from 20 

to 40 inches. 

Of minor extent in this unit are Bocker, Carmack, 

Loneridge, Mippon, and Tekison soils and areas of Rubble 

land and Rock outcrop. 

This unit is used as grazable woodland and for wildlife habitat. 

The Jumpe and Sutkin soils in this unit are suited to the 

production of Douglas-fir and ponderosa pine. Douglas-fir is the 

dominant species on the Jumpe soils, and ponderosa pine is 

the dominant species on the Sutkin soils. The areas of 

Rubble land and Rock outcrop can hinder harvesting. Use 

of conventional methods of harvesting trees may be difficult in 

the steeper areas. 

The Sapkin soils are well suited to the production of forage, 

but the production of forage is low on the Jumpe and Sutkin 

soils. The forage can be improved by seeding adapted species. 

The presence of logging debris limits seeding. 

This unit is well suited to use as habitat for elk, deer, and 

bighorn sheep. 

13. Naxing-Darland 

Very deep, well drained, gently sloping to very steep soils; 

on mountains and broad ridges 

This map unit is in the western part of the survey area. Slope is 

5 to 75 percent. The native vegetation is mainly conifers, grasses, 

forbs, and shrubs. Elevation is 5,000 to 7,000 feet. The 

average annual precipitation is 22 to 50 inches, the average 

annual air temperature is about 41 degrees F, and the average 

growing season, at 28 degrees F, is 80 to 120 days. 

This unit makes up about 5 percent of the survey area. It is 

about 45 percent Naxing soils and 10 percent Darland soils. 

The remaining 45 percent is components of minor extent. 

Naxing soils are on mountains and broad ridges. These soils 

formed in colluvium derived dominantly from basalt, volcanic 

ash, and loess. The surface layer is stony loam or loam. The 

subsoil is very cobbly loam. The substratum to a depth of 60 

inches or more is extremely cobbly loam. 

Darland soils are on south-facing mountainsides. These 

soils formed in colluvium derived from basalt. The surface 

layer is stony loam, very gravelly loam, or very cobbly loam. 

The subsoil is extremely cobbly loam. The substratum to a 

depth of 60 inches or more is extremely cobbly sandy loam. 

Of minor extent in this unit are Tumac soils, Cryumbrepts, 

moderately well drained Saydab soils, and Aquic Cryandepts. 

This unit is used as grazable woodland, as rangeland, and for 

wildlife habitat. 

The Naxing soils are suited to the production of subalpine 

fir, western larch, lodgepole pine, and Engelmann spruce; 

however, stands of merchantable 
timber are not produced on these soils. The large amount of 

volcanic ash in the soils increases the risk of erosion and results 

in low load-bearing strength. Additions of coarse base rock 

are needed for roads. 

The Darland soils are not forested and are suited to the 

production of forage. The main limitations are the short growing 

season, steepness of slope, and stones on the surface. 

Steepness of slope limits accessibility. The production of forage 

on the Naxing soils is limited by the density of the overstory 

canopy and the short growing season. The presence of logging 

debris limits seeding. 

This unit is well suited to habitat for bears and other 

mammals and to summer range for deer and elk. 

broad land use considerations 

The soils in this survey area have potential for a variety of 

uses such as irrigated cropland, orchards, nonirrigated 

cropland, rangeland, grazable woodland, wildlife habitat, 

homesite development, and recreation. 

Approximately 30 percent of the acreage in the survey area 

is used as irrigated cropland. The major crops grown include 

apples, cherries, hops, asparagus, and corn. Grasses and 

legumes are grown for hay, pasture, and seed. The areas of 

cropland are primarily in valleys in general map units 1, 2, 3, 4, 5, 

7, and 8. The Lickskillet and Starbuck soils in map unit 6 are 

shallow and are suited to permanent pasture or to orchards with a 

perennial cover crop. The Ritzville soils in map unit 8 are well 

suited to irrigated crops if irrigation water is available. The main 

limitation is the hazard of erosion. The Tieton soils in map unit 9 

are also used for irrigated crops. 

The soils in map unit 1 have a seasonal high water table, are 

subject to flooding, and are affected by salts or alkali in some 

areas. Installing adequate drains and leaching excess salts may 

be needed to achieve optimum yields. The soils in map unit 2 

have low available water capacity, and frequent applications of 

irrigation water are needed. The soils in map unit 3 are sandy and 

are subject to a high hazard of wind erosion. Frequent 

applications of irrigation water are needed to reduce soil 

blowing and to satisfy crop needs. Map unit 4 is the largest and 

best suited unit for use as irrigated cropland. It consists mainly 

of Warden soils. The hazard of erosion is the main limitation in 

map units 4, 5, 7, and 8. Soils that are moderately deep or 

shallow to a hardpan are a concern in map units 5 and 7 

because the hardpan is a limitation for the construction of 

irrigation systems. 

About 7 percent of the acreage in the area is used 

as nonirrigated cropland. The soils in map units 4, 8, and 9 are well 

suited to a winter wheat-fallow cropping system. These include 

the Warden, Ritzville, and Taneum soils. The Harwood and Willis 

soils in map units 5 and 7 are suited to nonirrigated winter wheat 

but are less productive than the Warden, Ritzville, and Taneum 

soils. 

About 48 percent of the survey area is used as rangeland. 

Most of the areas of rangeland are on soils in map units 6, 7, 10, 

and 11. These include the Lickskillet, Willis, Rock Creek, and 

Roza soils. Soils in most other map units are well suited to use 

as rangeland, but their characteristics allow them to be used for 

more intensive purposes. The soils in map units 12 and 13 are 

forested, but they provide low yields of forage. These include 

the Jumpe, Sutkin, and Naxing soils. 

About 15 percent of the survey area is used as grazable 

woodland, which is mainly in map units 12 and 13. The Jumpe 

and Sutkin soils in unit 12 produce good stands of Douglas-fir. 

The soils in map unit 13 generally are less productive because 

of the climate. 

The soils in all of the map units are suited to wildlife habitat. 

Wetland and shallow water areas in map units 1 and 2 provide 

good habitat for waterfowl and wading birds. Map units 3, 4, 5, 6, 

7, 8, 9, and 10 provide suitable habitat for upland game birds such 

as dove, pheasant, and quail. The soils in map units 9, 11, and 12 

provide good habitat for big game such as deer, elk, and some 

bighorn sheep. 

Most of the map units are suited to use as homesites. In 

general, the nearly level to strongly sloping Warden and Ritzville 

soils in map units 4 and 8 are well suited for use as homesites. 

Depth to the hardpan or bedrock severely limits the soils in map 

units 5, 6, and 7 for use as homesites. Map unit 1 is poorly suited 

because of the hazard of flooding and wetness. The Weirman 

soils in map unit 2 are also subject to flooding. The Roza soils 

in map unit 11 are poorly suited for use as homesites because 

of high shrink-swell potential. In the other map units, steepness 

of slope, depth to rock, permeability, and stones are the main 

limitations. 

The soils in map units 1 and 2 have low potential for use as 

recreation sites because of the hazard of flooding. The 

soils in the other map units have some potential, depending on 

steepness of slope, soil depth, and the characteristics of the 

surface layer. Map units 10, 11, and 12 are used most 

extensively for hiking, horseback riding, cross-country skiing, 

fishing, hunting, and snowmobiling, The Oak Creek and L. 

T. Murray Wildlife Recreation Areas and the Darland 

Loop are in these map units. The Yakima River, north of 

Selah, is used for boating and rafting. 
detailed soil map units 

The map units on the detailed soil maps at the back of this survey 

represent the soils in the survey area. The map unit descriptions 

in this section, along with the soil maps, can be used to 

determine the suitability and potential of a soil for specific uses. 

They also can be used to plan the management needed for 

those uses. More information on each map unit, or soil, is 

given under "Use and management of the soils." 

Each map unit on the detailed soil maps represents an area on 

the landscape and consists of one or more soils for which the unit

is named. 

A symbol identifying the soil precedes the map unit name in 

the soil descriptions. Each description includes general facts 

about the soil and gives the principal hazards and limitations 

to be considered in planning for specific uses. 

Soils that have profiles that are almost alike make up a soil 

series. Except for differences in texture of the surface layer or of 

the underlying material, all the soils of a series have major 

horizons that are similar in composition, thickness, and 

arrangement. 

Soils of one series can differ in texture of the surface layer or of 

the underlying material. They also can differ in slope, stoniness, 

salinity, wetness, degree of erosion, and other characteristics 

that affect their use. On the basis of such differences, a soil 

series is divided into soil phases. Most of the areas shown on 

the detailed soil maps are phases of soil series. The name of a soil 

phase commonly indicates a feature that affects use or 

management. For example, Warden silt loam, 2 to 5 percent 

slopes, is one of several phases in the Warden series. 

Some map units are made up of two or more major soils. 

These map units are called soil complexes. 

A soil complex consists of two or more soils in such an 

intricate pattern or in such small areas that they cannot be 

shown separately on the soil maps. The pattern and proportion 

of the soils are somewhat similar in all areas. Harwood-Gorst 

complex, 0 to 25 percent slopes, is an example. 

Most map units include small scattered areas of soils other 

than those for which the map unit is named. Some of these 

included soils have properties that differ substantially from 

those of the major soil or soils. Such differences could 

significantly affect use and management of the soils in the map 

unit. The included soils are identified in each map unit 

description. Some 

small areas of strongly contrasting soils are identified by a 

special symbol on the soil maps. 

This survey includes miscellaneous areas. Such areas have 

little or no soil material and support little or no vegetation. Rock 

outcrop is an example. Miscellaneous areas are shown on the 

soil maps. Some that are too small to be shown are identified 

by a special symbol on the soil maps. 

Table 4 gives the acreage and proportionate extent of each 

map unit. Other tables (see "Summary of tables") give properties 

of the soils and the limitations, capabilities, and potentials for 

many uses. The Glossary defines many of the terms used in 

describing the soils. 

map unit descriptions 

1-Aquic Cryandepts, gently sloping. These deep, 

moderately well drained soils are in swales on alluvial fans and on 

stream terraces. They formed in alluvium that is derived from 

basalt and contains some volcanic ash and loess. Slope is 0 

to 3 percent. The native vegetation is mainly grasses. 

Elevation is 4,400 to 6,300 feet. The average annual 

precipitation is 30 to 50 inches, the average annual air 

temperature is about 41 degrees F, and the average frost-free 

season is 60 to 95 days. 

No single profile is typical of Aquic Cryandepts, but one 

commonly observed in the survey area has a surface layer of 

dark brown and brown silt loam about 15 inches thick. The 

subsoil is yellowish brown extremely cobbly silt loam and light 

yellowish brown very cobbly sandy loam about 16 inches thick. 

The substratum is yellow very gravelly silt loam about 13 inches 

thick. Basalt is at a depth of about 44 inches. Depth to basalt 

ranges from 40 to 60 inches or more. 

Included in this unit are areas of poorly drained and somewhat 

poorly drained soils in depressional areas and some areas of 

soils that have a clay subsoil. Included areas make up about 

15 percent of the total acreage. 

Permeability of these Aquic Cryandepts is moderate. Effective 

rooting depth is 40 to 60 inches or more. Available water 

capacity is moderate. Runoff is slow, and the hazard of water 

erosion is slight. 

This unit is used as rangeland and for wildlife habitat and 

recreation. 

The present vegetation is mainly bluegrass, fescue, 

sedges, quaking aspen, and false-hellebore. The 

production of forage is limited by the short growing 
season. Because this unit consists of open meadows 

interspersed with heavily timbered areas, grazing 

pressure can be severe. The establishment of salt licks and 

livestock watering facilities away from the meadows or 

construction of management fences improves the distribution 

of grazing by livestock and wildlife and reduces the 

grazing pressure on the meadows. 

Following severe overgrazing, seeding reduces soil 

erosion, preserves water quality, and increases production. 

Seeding can be done at any time of the year, but seeding 

late in summer or in fall is most successful. Soil wetness is 

the major factor limiting seeding. Broadcast seeding is the 

most effective method. Adapted grasses and legumes 

should be seeded on this unit. 

This map unit is in capability subclass 

VIw, nonirrigated. 

2-Ashue loam. This very deep, well drained soil is 

on low terraces. It formed in alluvium. Slope is 0 to 2 

percent. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 700 to 1,700 feet. The 

average annual precipitation is 7 to 9 inches, the average 

annual air temperature is about 51 degrees F, and the 

average frost-free season is 130 to 180 days. 

Typically, the surface layer is brown loam about 10 inches 

thick. The upper part of the subsoil is yellowish brown very 

gravelly loam about 5 inches thick, and the lower part is 

yellowish brown very gravelly sandy clay loam about 14 

inches thick. The upper part of the substratum is dark 

yellowish brown very gravelly sandy loam about 5 inches 

thick, and the lower part to a depth of 60 inches or more is 

dark grayish brown extremely gravelly sand. In some areas 

the surface layer is cobbly or gravelly. 

Included in this unit are small areas of Naches, 

Weirman, Logy, Zillah, and Yakima soils. 

Permeability of this Ashue soil is moderately slow above 

the extremely gravelly sand part of the substratum and very 

rapid through it. Available water capacity is low. Effective 

rooting depth is 60 inches or more. Runoff is slow, and the 

hazard of water erosion is slight. 

This unit is used for irrigated field and orchard crops, 

wildlife habitat, and homesites. The main irrigated crops 

are corn, grapes, mint, peas, tree fruit, and 

asparagus. Grasses and legumes are grown for hay, 

pasture, and seed. 

The main limitation for irrigated crops is the low available 

water capacity. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to the soil in this unit. The 

type of irrigation system used generally depends on the 

kind of crop grown. If surface irrigation is used, the risk of 

erosion can be minimized by keeping runs short. Use of 

sprinkler or drip irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity, the water intake rate, and the crop 

needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content 

and tilth. Using a cropping system that includes closegrowing, high-residue crops in the rotation and maintaining 

crop residue on the surface reduce water erosion. Use of 

vegetated filter strips at the end of rows reduces the 

volume of sediment in the tailwater. Exposing the very 

gravelly part of the substratum when leveling fields should be 

avoided. Shallow cuts are feasible in some areas. 

This unit is poorly suited to homesite development. The 

main limitation is the content of gravel and large stones. 

Dustiness can be a problem during construction on large 

building sites. Building sites should be disturbed as little as 

possible. Cutbanks are not stable and are subject to caving 

in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage from 

onsite sewage disposal systems. Large stones can interfere 

with the installation of absorption fields. 

This map unit is in capability subclass Ills, irrigated. 

3-Bakeoven very cobbly silt loam, 0 to 30 percent 

slopes. This very shallow, well drained soil is on uplands. It 

formed in loess and in residuum derived from basalt. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,500 to 3,200 feet. The average annual 

precipitation is 10 to 12 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 150 days. 

Typically, the surface layer is brown very cobbly silt loam 

about 4 inches thick. The upper part of the subsoil is dark 

yellowish brown gravelly clay loam about 3 inches thick, and 

the lower part is dark yellowish brown very gravelly clay 

loam about 3 inches thick. Basalt is at a depth of about 10 

inches. Depth to basalt ranges from 4 to 12 inches. In some 

areas the surface layer is stony. 

Included in this unit are areas of Lickskillet, Moxee, 

and Starbuck soils. 

Permeability of this Bakeoven soil is moderately slow. 

Available water capacity is low. Effective rooting depth is 4 

to 12 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as rangeland, for wildlife habitat, and as 

homesites. 

The potential native vegetation on this unit is mainly stiff 

sagebrush and Sandberg bluegrass. The production of 

forage is limited by the low available water capacity. If the 

range is overgrazed, the proportion of preferred forage 

plants such as Sandberg bluegrass decreases and the 

proportion of less preferred forage plants such as forbs, 

sagebrush, and annual grasses increases. 
Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

chemical treatment, and prescribed burning. Seeding on this 

unit generally is not practical. 

This unit is poorly suited to homesite development. The main 

limitations are very shallow depth to rock, large stones, and 

steepness of slope in areas where the slope is more than 15 

percent. The very shallow depth to rock hinders excavation. 

The main limitations for septic tank absorption fields are large 

stones, very shallow depth to rock, and steepness of slope. 

Because of the very shallow depth to rock and steepness of 

slope, effluent from absorption fields can surface in downslope 

areas and thus create a hazard to health. Large stones can 

interfere with the installation of absorption lines. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

4-Bickleton silt loam, 0 to 5 percent slopes. This deep, 

well drained soil is on uplands. It formed in loess and in 

residuum derived from basalt. The native vegetation is mainly 

grasses and forbs. Elevation is 2,600 to 3,200 feet. The 

average annual precipitation is 11 to 14 inches, the average 

annual air temperature is about 47 degrees F, and the average 

frost-free season is 120 to 160 days. 

Typically, the surface layer is dark grayish brown silt loam 

about 10 inches thick. The subsoil is brown silt loam about 16 

inches thick. The upper part of the substratum is pale brown 

silt loam about 9 inches thick, and the lower part is calcareous, 

brown extremely gravelly silty clay loam about 7 inches thick. 

Basalt is at a depth of about 42 inches. Depth to basalt 

ranges from 40 to 60 inches. In some areas a thin capping of 

gravel conglomerate overlies the basalt. 

Included in this unit are areas of Renslow and Rock Creek 

soils and areas of Bickleton soils that have slopes of more 

than 5 percent. 

Permeability of this Bickleton soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 60 

inches. Runoff is slow, and the hazard of water erosion is 

slight. 

This unit is used for nonirrigated crops, for wildlife habitat, 

and as rangeland. 

The main limitations for nonirrigated crops are the low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. 

Erosion can be reduced by seeding fall grain early, stubble 

mulching, tilling on the contour or across the slope, and 

shaping waterways and seeding them to perennial grass. 

Drop structures are needed in places to control the flow of 

runoff in waterways. Use of terraces, diversions, and 

stripcropping, either singly or in combination, is advisable on 

long slopes. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Idaho fescue, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less preferred 

forage plants such as Sandberg bluegrass, cheatgrass, big 

sagebrush, and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

beating, chemical treatment, plowing, and prescribed burning. 

Range seeding is a suitable practice if the range vegetation is 

in poor condition. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass Ille, nonirrigated. 

5-Bickleton silt loam, 5 to 20 percent slopes. This deep, 

well drained soil is on uplands. It formed in loess and in 

residuum derived from basalt. Slope is dominantly about 10 

percent. The native vegetation is mainly grasses and forbs. 

Elevation is 2,600 to 3,200 feet. The average annual 

precipitation is 11 to 14 inches, the average annual air 

temperature is about 47 degrees F, and the average frost-free 

season is 120 to 160 days. 

Typically, the surface layer is dark grayish brown silt loam 

about 10 inches thick. The subsoil is brown silt loam about 16 

inches thick. The upper part of the substratum is calcareous, 

pale brown silt loam about 9 inches thick, and the lower part 

is calcareous, brown extremely gravelly silty clay loam about 7 

inches thick. Basalt is at a depth of about 42 inches. Depth to 

basalt ranges from 40 to 60 inches. In some areas a thin capping 

of gravel overlies the basalt. 

Included in this unit are areas of Renslow and Rock Creek 

soils and areas of Bickleton soils that have slopes of more 

than 20 percent. 

Permeability of this Bickleton soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 60 inches. 

Runoff is medium, and the hazard of water erosion is moderate. 

This unit is used for nonirrigated crops and as 

rangeland. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. 

Erosion can be reduced by seeding fall grain early, stubble 

mulching, tilling on the contour or across the slope, and shaping 

waterways and seeding them to perennial grass. Drop 

structures are needed in places to control the flow of runoff in 

waterways. Terracing and stripcropping, either singly or in 

combination, may also be advisable. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Idaho fescue, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 
preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less preferred 

forage plants such as Sandberg bluegrass, cheatgrass, big 

sagebrush, and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

beating, chemical treatment, plowing, and prescribed burning. 

Range seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass Ille, nonirrigated. 

6-Bocker very cobbly loam, 0 to 25 percent slopes. This 

very shallow, well drained soil is on mountaintops and broad 

ridgetops. It formed in residuum that is derived from basalt and 

includes a small amount of loess. The native vegetation is 

mainly grasses and shrubs. Elevation is 2,800 to 5,500 feet. 

The average annual precipitation is 18 to 40 inches, the 

average annual air temperature is about 42 degrees F, and the 

average frost-free season is 85 to 130 days. 

Typically, the surface layer is dark grayish brown very cobbly 

loam about 3 inches thick. The subsoil is dark brown very 

cobbly loam about 4 inches thick. Fractured basalt is at a 

depth of about 7 inches. Depth to basalt ranges from 5 to 10 

inches. 

Included in this unit are about 15 percent Sapkin soils on 

mounds and about 5 percent Jumpe, Sutkin, and Loneridge 

soils. 

Permeability of this Bocker soil is moderate. Available 

water capacity is low. Effective rooting depth is 5 to 10 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on this unit is mainly 

Sandberg bluegrass, bottlebrush squirreltail, and eriogonum. 

The production of forage is limited by cobbles on the surface, 

very shallow depth to rock, and low available water capacity. If 

the range is overgrazed, the proportion of preferred forage 

plants such as Sandberg bluegrass and buckwheat 

decreases and the proportion of less preferred forage plants 

such as forbs and cheatgrass increases. 

This unit is limited for livestock watering ponds and other 

water impoundments because of the very shallow depth to 

rock. Water tanks, springs, wells, and pipeline systems can be 

used to provide water for livestock. Seeding is not feasible 

because of the cobbles on the surface, low available water 

capacity, and very shallow soil depth. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

7-Bocker-Jumpe complex, 0 to 15 percent slopes. This 

map unit is on smooth mountaintops and broad ridges. Slope 

is dominantly 5 percent. The native 

vegetation is mainly grasses, shrubs, and scattered stands of 

conifers. Elevation is 3,500 to 5,000 feet. The average 

annual precipitation is 25 to 40 inches, the average annual 

air temperature is about 42 degrees F, and the average frostfree season is 85 to 130 days. 

This unit is about 60 percent Bocker very cobbly loam and 

about 35 percent Jumpe stony loam. The components of this unit 

are so intricately intermingled that it was not practical to map 

them separately at the scale used. 

Included in this unit is about 5 percent Sapkin soils. Also 

included are areas of Bocker and Jumpe soils that have 

slopes of more than 15 percent and soils that are 30 to 40 

inches deep over basalt. 

The Bocker soil is very shallow and well drained. It formed in 

residuum that is derived from basalt and includes a small 

amount of loess. Typically, the surface layer is dark grayish 

brown very cobbly loam about 3 inches thick. The subsoil is dark

brown very cobbly loam about 4 inches thick. Fractured basalt 

is at a depth of about 7 inches. Depth to basalt ranges from 5 

to 10 inches. 

Permeability of the Bocker soil is moderate. Available water 

capacity is low. Effective rooting depth is 5 to 10 inches, 

Runoff is medium, and the hazard of water erosion is 

moderate. 

The Jumpe soil is very deep and well drained. It formed in 

residuum that is derived from basalt and includes a small 

amount of loess. Typically, the surface is covered with a mat of 

partially decomposed organic material about 2 inches thick. 

The surface layer is brown stony loam about 3 inches thick. 

The subsoil is brown extremely cobbly loam. The substratum to 

a depth of 60 inches or more is yellowish brown extremely 

cobbly loam, In some areas the soil has an ashy mantle 4 to 12 

inches thick. 

Permeability of the Jumpe soil is moderate. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

slight. 

This unit is used for wildlife habitat and as rangeland and 

grazable woodland. 

Ponderosa pine and Douglas-fir are the main woodland 

species on the Jumpe soil. On the basis of a 100-year site 

curve, the mean site index is 67 for ponderosa pine and 80 for 

Douglas-fir. Yield tables for normal, even-aged, unmanaged 

stands indicate that the mean annual increment at culmination 

(CMAI) for trees 0.6 inch in diameter and larger is 52 cubic feet 

per acre for ponderosa pine at age 50 and 69 cubic feet per acre 

for Douglas-fir at age 40. The mean annual increment for trees 

6.6 inches in diameter and larger at 80 years of age is 40 cubic 

feet per acre for ponderosa pine and 55 cubic feet per acre for 

Douglas-fir. However, the typical basal area of stands on the 

Jumpe soil is about 70 percent that of normal stands, and the 

total yield is correspondingly lower. 
The main concern for the harvesting of timber on the 

Jumpe soil is gaining access to the widely scattered, 

irregularly shaped timbered areas. The cobbles on the 

surface of the Bocker soil make access to the forested 

Jumpe soil difficult and thus hinder harvesting. Wheeled and 

tracked equipment can be used in skidding operations. 

Unsurfaced roads and skid trails are slippery when wet, and 

they may be impassable during spring runoff or in rainy 

periods. Logging roads require suitable surfacing for yearround use. Rock for road construction generally is available 

on this unit. 

Seedling establishment is the main concern in the 

production of timber on the Jumpe soil. If seed trees are 

present, natural reforestation of cutover areas by ponderosa 

pine and Douglas-fir occurs infrequently. Reforestation 

can be accomplished by planting ponderosa pine and 

Douglas-fir seedlings. The droughtiness of the surface 

layer during the dry summer months increases seedling 

mortality, especially on south- and southwest-facing slopes. 

The common forest understory plants on the Jumpe soil 

are elk sedge, pinegrass, lupine, ceanothus, and bitterbrush. 

The crown density in the areas where the woodland site 

index was measured is 20 percent. This soil is well suited to 

grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer 

or in fall generally is most successful. 

The potential native rangeland vegetation on the Bocker 

soil is mainly Sandberg bluegrass, carrotleaf lomatium, 

and bottlebrush squirreltail. If the range is overgrazed, the 

proportion of preferred forage plants such as Sandberg 

bluegrass decreases and the proportion of less desirable 

forbs and annual grasses increases. The main limitations for 

the use of the Bocker soil as rangeland are cobbles on the 

surface, low available water capacity, and depth to rock. 

Livestock grazing during the hot summer months may 

concentrate on the tree-shaded Jumpe soil and on nearby 

areas of the Bocker soil. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

8-Bocker-Sapkin complex, 0 to 25 percent slopes. This 

map unit is on smooth mountaintops and broad ridges. Slope 

is dominantly about 5 percent. The native vegetation is 

mainly grasses and shrubs. Elevation is 3,200 to 5,000 

feet. The average annual precipitation is 18 to 35 inches, the 

average annual air temperature is about 42 degrees F, and 

the average frost-free season is 95 to 130 days. 

This unit is about 65 percent Bocker very cobbly loam, 0 

to 25 percent slopes, and about 30 percent Sapkin very 

stony loam, 10 to 25 percent slopes. The components of 

this unit are so intricately intermingled that it was not 

practical to map them separately at the scale used. 

Included in this unit are areas of Sapkin soils that have 

slopes of more than 15 percent, Jumpe and Sutkin soils, 

Rock outcrop, and soils that are similar to these Bocker and 

Sapkin soils but are 40 to 60 inches deep over bedrock. 

Included areas make up about 5 percent of the total 

acreage. 

The Bocker soil is very shallow and well drained. It formed 

in residuum that is derived from basalt and includes a small 

amount of loess. Typically, the surface layer is dark grayish 

brown very cobbly loam about 3 inches thick. The subsoil is 

dark brown very cobbly loam about 4 inches thick. Fractured 

basalt is at a depth of about 7 inches. Depth to basalt 

ranges from 5 to 10 inches. 

Permeability of the Bocker soil is moderate. Available 

water capacity is low. Effective rooting depth is 5 to 10 

inches. Runoff is medium, and the hazard of water erosion 

is moderate. 

The Sapkin soil is moderately deep and well drained. It 

formed in residuum that is derived from basalt and includes a 

small amount of loess. Typically, the surface layer is about 15 

inches thick. It is dark grayish brown very stony loam in the 

upper part and brown loam in the lower part. The upper part 

of the subsoil is brown cobbly loam about 12 inches thick, 

and the lower part is brown cobbly loam and extremely 

cobbly clay loam about 8 inches thick. Basalt is at a depth of 

about 35 inches. Depth to basalt ranges from 20 to 40 

inches. In some areas the surface layer is 4 to 10 inches 

thick. 

Permeability of the Sapkin soil is moderate. Available 

water capacity is low. Effective rooting depth is 20 to 40 

inches. Runoff is rapid, and the hazard of water erosion is 

moderate. 

This unit is used for wildlife habitat and as rangeland. 

The potential native vegetation on the Bocker soil is 

mainly Sandberg bluegrass, eriogonum, and bottlebrush 

squirreltail, and on the Sapkin soil it is mainly Idaho fescue, 

bluebunch wheatgrass, and threetip sagebrush. The 

production of forage is limited by the very cobbly surface 

layer, depth to rock, and low available water capacity. Areas 

that are heavily infested with undesirable vegetation can be 

improved with such practices as chemical treatment and 

prescribed burning. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

9-Bocker-Sutkin complex, 0 to 7 percent slopes. This 

map unit is on smooth mountaintops and broad ridges. 

Slope is dominantly about 5 percent. The native 

vegetation is mainly grasses, shrubs, and scattered 

trees. Elevation is 2,800 to 4,800 feet. The average annual 

precipitation is 18 to 22 inches, the average annual air 

temperature is about 42 degrees F, and the average frostfree season is 95 to 130 days. 

This unit is about 65 percent Bocker very cobbly loam and 

about 30 percent Sutkin stony loam. The components of 

this unit are so intricately intermingled 
that it was not practical to map them separately at the 

scale used. 

Included in the unit are small areas of Sutkin soils that 

have slopes of more than 15 percent or that have a very 

cobbly clay subsoil. Included areas make up about 5 percent 

of the total acreage. 

The Bocker soil is very shallow and well drained. It 

formed in residuum that is derived from basalt and includes 

a small amount of loess. Typically, the surface layer is dark 

grayish brown very cobbly loam about 3 inches thick. The 

subsoil is dark brown very cobbly loam about 4 inches thick. 

Fractured basalt is at a depth of about 7 inches. Depth to 

basalt ranges from 5 to 10 inches. 

Permeability of the Bocker soil is moderate. Available 

water capacity is low. Effective rooting depth is 5 to 10 

inches. Runoff is medium, and the hazard of water erosion 

is Slight.

The Sutkin soil is very deep and well drained. Typically, the 

surface layer is covered with a mat of partially decomposed 

organic material about 1/2 inch thick. The surface layer is dark 

brown stony loam about 10 inches thick. The subsoil is dark 

yellowish brown very cobbly loam and extremely cobbly loam 

about 28 inches thick. The substratum to a depth of 60 

inches or more is dark yellowish brown extremely cobbly 

loam. 

Permeability of the Sutkin soil is moderate. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

slight. 

This unit is used for wildlife habitat and as rangeland 

and grazable woodland. 

Ponderosa pine and Douglas-fir are the main 

woodland species on the Sutkin soil. On the basis of a 100-

year site curve, the mean site index is 67 for ponderosa pine 

and 81 for Douglas-fir. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 52 cubic feet per acre for ponderosa pine at age 50 

and 71 cubic feet per acre for Douglas-fir at age 45. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 40 cubic feet per acre for 

ponderosa pine and 50 cubic feet per acre for Douglas-fir. 

However, the typical basal area of stands on the Sutkin soil 

is about 90 percent that of normal stands, and the total yield 

is correspondingly lower. 

The main concern for the harvesting of timber is gaining 

access to the widely scattered, irregularly shaped 

timbered areas of the Sutkin soil. The cobbles on the surface 

of the Bocker soil make access to the forested Sutkin soil 

difficult and thus hinder harvesting. Wheeled and tracked 

equipment can be used in skidding operations. 

Unsurfaced roads and skid trails are slippery when 

wet, and they may be impassable during spring runoff 

or in rainy periods. Logging roads require suitable 

surfacing for year-round use. Rock for road construction 

generally is available on this unit. 

Seedling establishment on the Sutkin soil is the main 

concern in the production of timber. Where seed trees are 

present, natural reforestation of cutover areas by ponderosa 

pine and Douglas-fir occurs infrequently. Reforestation can 

be accomplished by planting ponderosa pine and 

Douglas-fir seedlings. Droughtiness of the soil increases 

seedling mortality, especially on south- and southwest-facing 

slopes. 

The common forest understory plants on the Sutkin soil 

are mainly pinegrass, elk sedge, yarrow, bitterbrush, 

and common snowberry. The crown density in the areas 

where the woodland site index was measured is 25 percent. 

This soil is well suited to grazing. Seeding to adapted 

grazable vegetation following logging or burning late in 

summer or in fall generally is most successful. 

 The potential native vegetation on the Bocker soil is 

mainly Sandberg bluegrass, eriogonum, and lomatium. The 

production of forage is limited by the very cobbly surface 

layer, depth to rock, and low available water capacity. 

If the range is overgrazed, the proportion of preferred 

forage plants such as Sandberg bluegrass decreases and 

the proportion of less desirable forbs and annual grasses 

increases. Livestock grazing during the hot summer months 

tends to concentrate on the shaded Sutkin soil and on 

nearby areas of the Bocker soil. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

10-Burke silt loam, 2 to 5 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed 

in loess over a lime- and silica-cemented hardpan. Slope 

is dominantly about 4 percent. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,000 to 

1,300 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is pale brown silt loam about 7 

inches thick. The substratum is pale brown silt loam about 18 

inches thick. A hardpan is at a depth of about 25 inches. 

Depth to the hardpan ranges from 20 to 40 inches. The 

hardpan commonly is underlain by basalt. In some areas the 

surface layer is very fine sandy loam, in some areas 

fragments of the hardpan are scattered throughout the profile 

and on the surface, and in some areas the hardpan is 

underlain by gravelly alluvium, tuffaceous sandstone, or 

alternate layers of loess and hardpan. 

Permeability of this Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. 
This unit is used for irrigated field and orchard crops, 

wildlife habitat, and homesites. The main irrigated crops are 

corn, grain, grapes, hops, mint, peas, and tree fruit. Grasses 

and legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

cemented pan and the hazard of water erosion. Furrow, 

corrugation, drip, and sprinkler irrigation systems are 

suited to the soil in this unit. The type of system used 

generally depends on the kind of crop grown. If furrow or 

corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of erosion can be 

minimized by keeping runs short. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content 

and tilth. Using a cropping system that includes closegrowing, high-residue crops in the rotation and maintaining 

crop residue on the surface reduce water erosion. 

Growing mint in meadows rather than in rows greatly 

reduces water erosion. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. Exposing the hardpan 

when leveling fields should be avoided. Shallow cuts are 

feasible in some areas. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the cemented pan, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

depth to the cemented pan, which limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclass Ille, irrigated. 

11-Burke silt loam, 5 to 8 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed 

in loess over a lime- and silica-cemented hardpan. The 

average size of areas is less than 35 acres. Slope is 

dominantly about 7 percent. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,000 to 1,300 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average 

frost-free season is 135 to 180 days. 

Typically, the surface layer is pale brown silt loam about 7 

inches thick. The substratum is pale brown silt loam about 

18 inches thick. A hardpan is at a depth of about 25 inches. 

Depth to the hardpan ranges from 20 to 40 inches. The 

hardpan commonly is underlain by basalt. In some areas the 

surface layer is very fine sandy loam, in some areas 

fragments of the hardpan are scattered throughout the 

profile and on the surface, and in some areas the hardpan is 

underlain by gravelly alluvium, tuffaceous sandstone, or 

alternate layers of loess and hardpan. 

Included in this unit are small areas of Scoon, Shano, 

and Starbuck soils. 

Permeability of this Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is rapid, and the hazard of water erosion is high. 

This unit is used for irrigated field and orchard crops, 

wildlife habitat, and homesites. The main irrigated crops are 

corn, mint, grain, grapes, peas, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

cemented pan, steepness of slope, and the hazard of water 

erosion. Drip and sprinkler irrigation systems are suited to the 

soil in this unit. The type of system used generally depends 

on the kind of crop grown. Use of drip or sprinkler irrigation 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. Cultivation prior to 

irrigation improves the water infiltration rate; however, the 

fine soil particles dislodged during cultivation are highly 

susceptible to water erosion. This makes the initial period of 

irrigation extremely critical. The water application rate should 

be reduced accordingly to help control runoff, erosion, and 

the production of sediment. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity and the crop needs. 

Use of minimum tillage-and return of crop residue to the 

soil improve the organic matter content and tilth. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation and maintaining crop residue on the 

surface reduce water erosion. Growing mint in meadows 

rather than in rows also greatly reduces water erosion. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the cemented pan, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 
The main limitation for septic tank absorption fields is the 

depth to the cemented pan, which limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclass Ille, irrigated. 

12-Burke silt loam, 8 to 15 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed 

in loess over a lime- and silica-cemented hardpan. Slope is 

dominantly about 12 percent. The native vegetation is mainly 

forbs and shrubs. Elevation is 1,000 to 1,300 feet. The

average annual precipitation is 6 to 9 inches, the average 

annual air temperature is about 50 degrees F, and the 

average frost-free season is 135 to 180 days. 

Typically, the surface layer is pale brown silt loam about 7 

inches thick. The substratum is pale brown silt loam about 

18 inches thick. A hardpan is at a depth of about 25 inches. 

Depth to the hardpan ranges from 20 to 40 inches. The 

hardpan is commonly underlain by basalt. In some areas the 

surface layer is very fine sandy loam, in some areas 

fragments of the hardpan are scattered throughout the 

profile and on the surface, and in some areas the hardpan is 

underlain by gravelly alluvium, tuffaceous sandstone, or 

alternate layers of loess and hardpan. 

Included in this unit are small areas of Scoon, Shano, 

and Starbuck soils and areas of Burke soils that have 

slopes of less than 8 percent or more than 15 percent. 

Permeability of this Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 

This unit is used for irrigated field and orchard crops, for 

nonirrigated crops, as rangeland, for wildlife habitat, and as 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. A cover crop is grown in orchards. Grasses and 

legumes are grown for hay, pasture, or seed. 

The main limitations for irrigated crops are depth to the 

cemented pan, steepness of slope, and the hazard of water 

erosion. Because of the steepness of slope, sprinkler and 

drip irrigation systems are best suited to the soil in this unit. If 

sprinkler irrigation is used, puddling reduces the water intake 

rate and impairs aeration. The water application rate should 

be reduced accordingly to help control runoff, erosion, and 

the production of sediment. To avoid loss of water and 

leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity and the crop needs. 

Use of annual or perennial cover crops reduces erosion. 

A rotation of grain followed by alfalfa and grass commonly 

is used. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, using diversions, and 

stripcropping. Drop structures are needed in places to 

control the flow of runoff in waterways. Waterways should 

be shaped and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and Sandberg bluegrass. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and proportion of less 

preferred forage plants such as big sagebrush, Sandberg 

bluegrass, and rabbitbrush increases. Areas that are heavily 

infested with undesirable vegetation can be improved by 

such methods as chaining, railing, beating, plowing, 

chemical treatment, and prescribed burning. Range 

seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses or legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the cemented pan, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

depth to the cemented pan, which restricts the capacity of 

the absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Steepness of slope and the 

cemented pan can cause lateral movement and surfacing of 

effluent in downslope areas. 

This map unit is in capability subclass lVe, irrigated 

and nonirrigated. 

13-Carmack loam, 0 to 25 percent slopes. This very 

deep, well drained soil is on uplands. It formed in residuum 

derived from basaltic conglomerate and tuffaceous 

sandstone. The native vegetation is mainly conifers, 

grasses, and shrubs. Elevation is 2,200 to 3,500 feet. The 

average annual precipitation is 20 to 35 inches, the average 

annual air temperature is about 43 degrees F, and the 

average growing season, at 28 degrees F, is 145 to 170 

days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

upper part of the surface layer, where mixed to a depth of 

about 7 inches, is brown loam. The lower part is pale brown 

loam about 8 inches thick. The upper part of the subsoil is 

brown loam and pale brown silty clay loam about 28 inches 

thick, and the lower part to a depth of 60 inches or more is 

pale brown loam. 

Included in this unit are small depressional areas that are 

poorly drained and areas of Carmack soils that have slopes 

of 25 to 50 percent. Included areas make up about 5 

percent of the total acreage. 
Permeability of this Carmack soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. Among the trees of limited extent are 

western larch and scattered grand fir. On the basis of a 100-

year site curve, the mean site index is 105 for Douglas-fir 

and 82 for ponderosa pine. Yield tables for normal, evenaged, unmanaged stands indicate that the mean annual 

increment at culmination (CMAI) for trees 0.6 inch in diameter 

and larger is 112 cubic feet per acre for Douglas-fir at age 

40 and 72 cubic feet per acre for ponderosa pine at age 40. 

The mean annual increment for trees 6.6 inches in diameter 

and larger at 80 years of age is 100 cubic feet per acre for 

Douglas-fir and 60 cubic feet per acre for ponderosa pine. 

However, the typical basal area of stands on this unit is 

about 70 percent that of normal stands, and the total yield is 

correspondingly lower. 

The main limitation for the harvesting of timber is short 

periods of seasonal soil wetness. Wheeled and tracked 

equipment can be used in skidding operations. Use of 

wheeled and tracked equipment when the soil is moist can 

produce ruts, compact the soil, and damage tree roots. 

Unsurfaced roads and skid trails are soft when wet, and they 

may be impassable during spring runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round 

use. Rock for road construction is not readily available on this 

unit. Skid trails and firebreaks in the steeper areas of this unit 

are subject to rilling and gullying unless adequate water 

bars are provided or they are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by Douglas-fir and ponderosa 

pine occurs periodically. Reforestation can be 

accomplished by planting Douglas-fir and ponderosa 

pine seedlings. Droughtiness of the soil increases seedling 

mortality, especially on south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, and American vetch. The crown 

density in the areas where the woodland site index was 

measured is 30 percent. This unit is well suited to grazing. 

Seeding to adapted grazable vegetation following 

logging or burning late in summer or in fall generally is most 

successful. 

This map unit is in capability subclass IVe, 

nonirrigated. 

14-Carmack cobbly loam, 25 to 50 percent slopes. 

This very deep, well drained soil is on uplands. It formed in 

residuum derived from basaltic conglomerate and tuffaceous 

sandstone. The native vegetation is 

conifers, grasses, and shrubs. Elevation is 2,200 to 3,500 

feet. The average annual precipitation is 20 to 35 inches, 

the average annual air temperature is about 43 degrees F, 

and the average growing season, at 28 degrees F, is 145 

to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

upper part of the surface layer, where mixed to a depth of 

about 7 inches, is brown cobbly loam. The lower part is pale 

brown loam about 8 inches thick. The upper part of the 

subsoil is brown loam and pale brown silty clay loam 28 

inches thick, and the lower part to a depth of 60 inches or 

more is pale brown loam. In some places, along 

drainageways and on convex slopes, the subsoil is gravelly. 

Included in this unit are areas of Rock outcrop and 

Rubble land and areas of Carmack soils that have slopes of 

less than 25 percent. Included areas make up about 5 

percent of the total acreage. 

Permeability of this Carmack soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. On the basis of a 100-year site curve, 

the mean site index is 87 for Douglas-fir and 77 for 

ponderosa pine. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 80 cubic feet per acre for Douglas-fir at age 40 and 

65 cubic feet per acre for ponderosa pine at age 45. The 

mean annual for trees 6.6 inches in diameter and larger at 

80 years of age is 65 cubic feet per acre for Douglas-fir and 

50 cubic feet per acre for ponderosa pine. However, the 

typical basal area of stands on this unit is about 75 percent 

that of normal stands, and the total yield is correspondingly 

lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. Cable yarding systems may be 

safer, and they disturb the soil less. Use of wheeled and 

tracked equipment when the soil is wet can produce ruts, 

compact the soil, and damage tree roots. Unsurfaced roads 

and skid trails are soft when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads require suitable surfacing for year-round use. Rock for 

road construction is not readily available on this unit. Steep 

yarding paths, skid trails, and firebreaks are subject to rilling 

and gullying unless adequate water bars are provided or 

they are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by Douglas-fir and 
ponderosa pine occurs periodically. Reforestation can be 

accomplished by planting Douglas-fir and ponderosa 

pine seedlings. The droughtiness of the soil increases 

seedling mortality, especially on south- and southwestfacing slopes. 

The common forest understory plants are elk sedge, 

bitterbrush, Oregon-grape, and pinegrass. The crown density 

in the areas where the woodland site index was measured is 

25 percent. This unit is suited to grazing and browsing. 

Seeding to adapted grazable vegetation following logging 

or burning late in summer or in fall generally is most 

successful. 

This map unit is in capability subclass Vle, 

nonirrigated. 

15-Carmack cobbly loam, 50 to 75 percent slopes. 

This very deep, well drained soil is on north-facing 

mountainsides. It formed in residuum derived from basaltic 

conglomerate and tuffaceous sandstone. The native 

vegetation is mainly conifers, grasses, and shrubs. 

Elevation is 2,200 to 3,500 feet. The average annual 

precipitation is 20 to 35 inches, the average annual air 

temperature is about 43 degrees F, and the average growing 

season, at 28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

upper part of the surface layer, where mixed to a depth of 

about 7 inches, is brown cobbly loam. The lower part is pale 

brown loam about 8 inches thick. The upper part of the 

subsoil is brown loam and pale brown silty clay loam about 

28 inches thick, and the lower part to a depth of 60 inches 

or more is pale brown loam. In some areas on knolls and 

along drainageways the subsoil is gravelly. 

Included in this unit are areas of Rock outcrop and 

Rubble land and areas of Carmack soils that have slopes 

of 25 to 50 percent. Included areas make up about 10 

percent of the total acreage. 

Permeability of this Carmack soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is high. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. Among the trees of limited extent are 

grand fir and western larch. On the basis of a 100-year site 

curve, the mean site index is 93 for Douglas-fir and 81 for 

ponderosa pine. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual 

increment at culmination (CMAI) for trees 0.6 inch in 

diameter and larger is 90 cubic feet per acre for Douglas-fir 

at age 40 and 71 cubic feet per acre for ponderosa pine at 

age 40. The mean annual increment for trees 6.6 inches in 

diameter and larger at 80 years of age is 55 cubic feet per 

acre for Douglas-fir and 40 cubic feet per acre for ponderosa 

pine. However, the typical 

basal area of stands on this unit is about 95 percent that of 

normal stands, and the total yield is correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which restricts the use of wheeled and 

tracked equipment in skidding operations. Cable yarding 

systems generally are safer, and they disturb the soil less. 

Harvesting systems that lift logs entirely off the ground 

reduce the disturbance of the protective layer of duff. Use of 

wheeled and tracked equipment when the soil is moist, 

produces ruts, compacts the soil, and damages tree roots. 

Unsurfaced roads and skid trails are soft when wet, and they 

may be impassable during spring runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round use. 

Rock for road construction is not readily available on this 

unit. Steep yarding paths, skid trails, and firebreaks are 

subject to rifling and gullying unless adequate water bars are 

provided or they are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas of Douglas-fir and ponderosa 

pine occurs periodically. Reforestation can be accomplished 

by planting Douglas-fir and ponderosa pine seedlings. The 

droughtiness of the soil in this unit increases seedling 

morality, especially on south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, and spirea. The production of understory 

vegetation is limited by the density of the overstory 

canopy. The crown density in the areas where the 

woodland site index was measured is 30 percent. 

This unit is poorly suited to grazing. Steepness of slope 

limits access by livestock. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. Because of the steepness 

of slope, broadcast seeding should be used. 

This map unit is in capability subclass VIle, 

nonirrigated. 

16-Carmack cobbly loam, 25 to 50 percent north 

slopes. This very deep, well drained soil is on north-facing 

mountainsides. It formed in residuum derived from basaltic 

conglomerate and tuffaceous sandstone. The native 

vegetation is mainly conifers, grasses, and shrubs. Elevation 

is 2,200 to 3,500 feet. The average annual precipitation is 20 

to 35 inches, the average annual air temperature is about 43 

degrees F, and the average growing season, at 28 degrees 

F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

upper part of the surface layer, where mixed to a depth of 

about 7 inches, is brown cobbly loam. The lower part is pale 

brown loam about 8 inches thick. The upper part of the 

subsoil is brown loam and pale brown silty clay loam about 

28 inches thick, and the lower part to a 
depth of 60 inches or more is pale brown loam. In some 

areas, on knolls and along drainageways, the subsoil is 

gravelly. 

Included in this unit are small areas of Rock outcrop and 

Rubble land and areas of Carmack soils that have slopes of 

less than 25 percent or more than 50 percent. Included 

areas make up about 10 percent of the total acreage. 

Permeability of this Carmack soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. Among the trees of limited extent are 

grand fir and western larch. On the basis of a 100-year site 

curve, the mean site index is 93 for Douglas-fir and 81 for 

ponderosa pine. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger at age 40 is 90 cubic feet per acre for Douglas-fir and 

71 cubic feet per acre for ponderosa pine. The mean annual 

increment for trees 6.6 inches in diameter and larger at 80 

years of age is 75 cubic feet per acre for Douglas-fir and 55 

cubic feet per acre for ponderosa pine. The basal area 

typically is about the same as that of normal stands. 

The main limitation for the harvesting of timber is 

steepness of slope, making the use of wheeled and tracked 

equipment difficult. Cable yarding systems may be 

safer, and they disturb the soil less. Use of wheeled and 

tracked equipment when the soil is moist can produce ruts, 

compact the soil, and damage tree roots. Unsurfaced roads 

and skid trails are soft when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads require suitable surfacing for year-round use. Rock 

for road construction is not readily available on this unit. 

Steep yarding paths, skid trails, and firebreaks are subject to 

rilling and gullying unless adequate water bars are provided 

or they are protected by plant cover. The protective layer of 

duff should be disturbed as little as possible. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by Douglas-fir and ponderosa 

pine occurs periodically. Reforestation can be accomplished 

by planting Douglas-fir and ponderosa pine seedlings. 

The droughtiness of the soil in this unit increases the 

mortality of seedlings. 

The common forest understory plants are elk sedge, 

pinegrass, spirea, lupine, western yarrow, and Oregongrape. 

The crown density in the areas where the woodland site 

index was measured is 40 percent. This unit is suited to 

grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer 

or in fall generally is most successful. 

This map unit is in capability subclass VIe, 

nonirrigated. 

17-Carmack-Rock outcrop complex, 40 to 70 percent 

slopes. This map unit is on mountainsides. Slope is 

dominantly about 50 percent. Areas face south. The native 

vegetation is mainly conifers, grasses, and shrubs. Elevation 

is 2,200 to 3,500 feet. The average annual precipitation is 20 

to 35 inches, the average annual air temperature is about 43 

degrees F, and the average growing season, at 28 degrees 

F, is 145 to 170 days. 

This unit is about 55 percent Carmack loam and about 35 

percent Rock outcrop. The components of this unit are so 

intricately intermingled it was not practical to map them 

separately at the scale used. 

Included in this unit are small areas of Carmack soils 

that have slopes of less than 40 percent and areas of 

shallow soils and Rubble land below the Rock outcrop. 

Included areas make up about 10 percent of the total 

acreage. 

The Carmack soil is very deep and well drained. It formed 

in residuum derived dominantly from basaltic conglomerate 

and tuffaceous sandstone. Typically, the surface is covered 

with a mat of partially decomposed organic material about 2 

inches thick. The upper part of the surface layer, where 

mixed to a depth of about 7 inches, is brown loam. The 

lower part is pale brown loam about 8 inches thick. The 

upper part of the subsoil is brown loam and silty clay loam 

about 28 inches thick, and the lower part to a depth of 60 

inches or more is pale brown loam. 

Permeability of this Carmack soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is high. 

Rock outcrop is exposed areas of bedrock occurring as 

bands and escarpments that generally extend from east 

to west. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and scattered Douglas-fir are the main 

woodland species on the Carmack soil. On the basis of a 

100-year site curve, the mean site index is 77 for ponderosa 

pine and 87 for Douglas-fir. Yield tables for normal, evenaged, unmanaged stands indicate that the mean annual 

increment at culmination (CMAI) for trees 0.6 inches in 

diameter and larger is 65 cubic feet per acre for ponderosa 

pine at age 45 and 80 cubic feet per acre for Douglas-fir at 

age 40. The mean annual increment for trees 6.6 inches in 

diameter and larger at 80 years of age is 50 cubic feet per 

acre for ponderosa pine and 65 cubic feet per acre for 

Douglas-fir. However, the typical basal area of stands is 

about 75 percent that of normal stands, and the total yield is 

correspondingly lower. 
The main limitations for the harvesting of timber are 

steepness of slope and the areas of Rock outcrop. The 

areas of Rock outcrop hinder harvesting and force yarding 

and skidding paths to converge, which results in increased 

potential for erosion and soil compaction. Unsurfaced roads 

are soft when wet, and they may be impassable during 

spring runoff or in rainy periods. Steep yarding paths, skid 

trails, and firebreaks are subject to rilling and gullying unless 

adequate water bars are provided or they are protected by 

plant cover. Logging roads require suitable surfacing for 

year-round use. Rock for road construction is available on 

this unit. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by ponderosa pine occurs 

infrequently. The areas of Rock outcrop limit the even 

distribution of reforestation. The droughtiness of the soil in 

this unit increases seedling mortality, especially on southand southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, bluebunch wheatgrass, common snowberry, 

and bitterbrush. The crown density in the areas where the 

woodland site index was measured is 20 percent. The 

Carmack soil is poorly suited to grazing. Steepness of slope 

and the areas of Rock outcrop limit access by livestock. 

Seeding to adapted grazable vegetation following logging or 

burning late in summer or in fall generally is most 

successful. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

18-Cleman very fine sandy loam, 0 to 2 percent 

slopes. This very deep, well drained soil is on flood plains 

and alluvial fans. It formed in alluvium. The native vegetation 

is mainly grasses, forbs, and shrubs. Elevation is 700 to 

1,600 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typically, the surface layer is brown very fine sandy loam 

about 10 inches thick. Below this to a depth of 60 inches 

or more is brown and yellowish brown, stratified fine sandy 

loam, sandy loam, very fine sandy loam, and silt loam. In 

some areas the surface layer is silt loam, fine sandy loam, 

or loam, in some areas very gravelly loamy sand is below a 

depth of about 30 inches, and in some areas the subsoil is 

sandy clay loam. 

Included in this unit are areas of Outlook, Esquatzel, 

Warden, Ashue, and Naches soils. 

Permeability of this Cleman soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is very slow, and the hazard of water erosion is 

slight. This unit is subject to rare periods of flooding. The 

hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain, grapes, hops, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitation for irrigated crops is the hazard of soil 

blowing. Using a cropping system that includes closegrowing, high-residue crops in the rotation, maintaining crop 

residue on the surface, and using minimum tillage reduce 

soil blowing. Mulching may be needed to stabilize small 

areas where soil blowing begins. Using vegetated filter 

strips at the end of rows or using sediment ponds, or both, 

reduces the volume of sediment in the tailwater. 

Furrow, corrugation, drip, and sprinkler irrigation systems 

are suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. If surface irrigation 

systems are used, the risk of water erosion can be 

minimized by keeping runs short. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of water erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is the hazard of flooding. Dikes and channels that 

have outlets to bypass floodwater can be used to protect 

buildings and onsite sewage disposal systems from 

flooding. Dustiness can be a problem during construction on 

large building sites; therefore, these sites should be 

disturbed as little as possible. Cutbanks are not stable and 

are subject to caving in. 

This map unit is in capability subclass Ile, irrigated. 

19-Cleman very fine sandy loam, 2 to 5 percent 

slopes. This very deep, well drained soil is on flood plains. 

It formed in alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 700 to 1,600 feet. 

The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 150 days. 

Typically, the surface layer is brown very fine sandy loam 

about 10 inches thick. Below this to a depth of 60 inches 

or more is brown and yellowish brown, stratified fine sandy 

loam, sandy loam, very fine sandy loam, and silt loam. In 

some areas the surface layer is silt loam, fine sandy loam, 

or loam; in some areas very gravelly loamy sand is below a 

depth of about 40 inches; and in some areas the subsoil is 

sandy clay loam. 

Included in this unit are areas of Esquatzel, Warden, 

Outlook, Ashue, Willis, Moxee, and Ritzville soils. Also 

included are areas of Cleman soils that have slopes of 

less than 2 percent. 

Permeability of this Cleman soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is slow, and the hazard of water 
erosion is moderate. This unit is subject to rare periods of 

flooding. The hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grapes, 

hops, peas, and tree fruits. Grasses and legumes are 

grown for hay, pasture, and seed. 

The main limitations for irrigated crops are the hazards of 

soil blowing and water erosion. Using a cropping system 

that includes close-growing, high-residue crops in the 

rotation, maintaining crop residue on the surface, and using 

minimum tillage reduce erosion. Mulching may be needed to 

stabilize small areas where soil blowing begins. Using 

vegetated filter strips at the end of rows or using sediment 

ponds, or both, reduces the volume of sediment in the 

tailwater. 

Furrow, corrugation, drip, or sprinkler irrigation systems 

are suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. If furrow or corrugation 

irrigation systems are used, runs should be on the 

contour or across the slope. The risk of water erosion can 

be minimized by keeping runs short. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of water erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. Pipe, ditch lining, or drop 

structures should be installed in irrigation ditches to facilitate 

irrigation and prevent excessive ditch erosion. 

The main limitations for nonirrigated crops are low annual 

precipitation, the hazard of soil blowing, and the hazard of 

water erosion. Because precipitation is not sufficient for 

annual cropping, a cropping system that includes winter 

wheat and summer fallow is most suitable. Soil blowing can 

be reduced by stripcropping and orienting rows at right 

angles to the prevailing wind. Water erosion can be reduced 

by seeding early in fall, using stubble mulch tillage, and 

shaping and seeding waterways to perennial 

grasses. Drop structures are needed in a few places to 

stabilize the flow of runoff in waterways. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, needleandthread, and big 

sagebrush. The production of forage is limited by the 

hazard of soil blowing. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as railing, chaining, beating, and chemical treatment. 

 This unit is limited for livestock watering ponds and 

other water impoundments because of seepage. Water 

tanks, springs, wells, and pipeline systems can be used to 

provide water for livestock. 

Range seeding is a suitable practice if the range 

vegetation is in poor condition. Seeding should be done in 

fall using a drill. Adapted legumes and grasses should be 

seeded on this unit. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is the hazard of flooding. Dikes and channels that 

have outlets to bypass floodwater can be used to protect 

buildings and onsite sewage disposal systems from flooding. 

These sites should be disturbed as little as possible. 

Cutbanks are not stable and are subject to caving in. 

This map unit is in capability subclasses Ile, irrigated, 

and Ille, nonirrigated. 

20-Cleman very fine sandy loam, 5 to 8 percent 

slopes. This very deep, well drained soil is on alluvial fans. 

It formed in alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 700 to 1,600 feet. 

The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 150 days. 

Typically, the surface layer is brown very fine sandy loam 

about 10 inches thick. Below this to a depth of 60 inches or 

more is brown and yellowish brown, stratified fine sandy 

loam, sandy loam, very fine sandy loam, and silt loam. In 

some areas gravelly loamy sand is below a depth of about 

40 inches, and in some areas the subsoil is sandy clay loam.

Included in this unit are small areas of Ashue and 

Naches soils. 

Permeability of this Cleman soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water erosion 

is moderate. The hazard of soil blowing is high. This unit is 

subject to rare periods of flooding. 

This unit is used for irrigated field and orchard crops, as 

rangeland, for wildlife habitat, and as homesites. The main 

irrigated crops are grain, grapes, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and seed.

The main limitations for irrigated crops are the hazards of 

soil blowing and water erosion. Using a cropping system 

that includes close-growing, high-residue crops in the 

rotation, maintaining crop residue on the surface, and using 

minimum tillage reduce erosion. Mulching may be needed to 

stabilize small areas where soil blowing begins. 

Sprinkler and drip irrigation systems are suited to the soil 

in this unit. The type of system used depends on the kind of 

crop grown. Use of these irrigation systems permits the 

even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from 
overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, needleandthread, and big 

sagebrush. The production of forage is limited by the hazard 

of soil blowing. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. Areas that 

are heavily infested with undesirable vegetation car,

 be 

improved by such methods as railing, chaining, beating, 

and chemical treatment. 

This unit is limited for livestock watering ponds and 

other water impoundments because of seepage. Water 

tanks, springs, wells, and pipeline systems can be used to 

provide water for livestock. 

Range seeding is a suitable practice if the range 

vegetation is in poor condition. This unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is the hazard of flooding. Dikes and channels that 

have outlets to bypass floodwater can be used to protect 

buildings and onsite sewage disposal systems from flooding. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. Cutbanks are not stable and are subject to 

caving in. 

This map unit is in capability subclass Ille, irrigated 

and nonirrigated. 

21-Cleman very fine sandy loam, 8 to 15 percent 

slopes. This very deep, well drained soil is on alluvial fans. It 

formed in alluvium. Native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 700 to 1,600 feet. The 

average annual precipitation is 8 to 12 inches, the average 

annual air temperature is about 50 degrees F, and the 

average frost-free season is 135 to 150 days. 

Typically, the surface layer is brown very fine sandy loam 

about 10 inches thick. Below this to a depth of 60 inches or 

more is brown and yellowish brown, stratified fine sandy 

loam, sandy loam, very fine sandy loam, and silt loam. In 

some areas gravelly loamy sand is below a depth of about 

40 inches, and in some areas the subsoil is sandy clay loam.

Included in this unit are small areas of Ashue and Naches 

soils and areas of Cleman soils that have slopes of less 

than 8 percent. 

Permeability of this Cleman soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more, Runoff is medium, and the hazard of water erosion 

is moderate. The hazard of soil blowing is high. This unit is 

subject to rare periods of flooding. 

This unit is used for irrigated field and orchard crops, for 

nonirrigated crops, as rangeland, for wildlife habitat, and as 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. Grasses and legumes are grown for hay, 

pasture, or seed. A cover crop is grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope, the hazard of soil blowing, and the hazard of water 

erosion. Using a cropping system that includes closegrowing, high-residue crops in the rotation and maintaining 

crop residue on the surface reduce erosion. A rotation of 

grain followed by alfalfa and grass commonly is used. 

Mulching may be needed to stabilize small areas where soil 

blowing begins. 

Sprinkler and drip irrigation systems are suited to the soil 

in this unit. Use of these systems permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of water erosion. To avoid loss of water 

and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted-to the 

available water capacity, the water intake rate, and the crop 

needs. 

The main limitations for nonirrigated crops are low annual 

precipitation, the hazard of soil blowing, and the hazard of 

water erosion. Because precipitation is not sufficient for 

annual cropping, a cropping system that includes winter 

wheat and summer falllow is most suitable. Soil blowing can 

be reduced by stripcropping, stubble mulch farming, and 

seeding early and at right angles to the prevailing wind. 

Seeding early in fall and tilling and chiseling stubble fields 

either on the contour when the soil is dry or across the 

slope reduce water erosion. Construction of level terraces 

and stripcropping, either singly or in combination, may be 

needed. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, needleandthread, and big 

sagebrush. The production of forage is limited by the 

hazard of soil blowing. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as railing, 

chaining, beating, and chemical treatment. 

This unit is poorly suited to livestock watering ponds 

because of seepage. Other water storage systems or 

pipelines should be used to provide water for livestock. 

Range seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. 

The main limitation is the hazard of flooding. Dikes and 
channels that have outlets to bypass floodwater can be 

used to protect buildings. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

the hazard of flooding and steepness of slope. Slope can 

cause lateral seepage of effluent so that it surfaces in 

downslope areas. Septic tank absorption lines should be 

installed on the contour. Cutbanks are not stable and are 

subject to caving in. 

This map unit is in capability subclass IVe, 

irrigated, and Ille, nonirrigated. 

22-Clint very stony loam, 15 to 45 percent slopes. 

This moderately deep, well drained soil is on uplands. It 

formed in loess and in residuum derived from basalt. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 2,300 to 3,300 feet. The average annual 

precipitation is 15 to 18 inches, the average annual air 

temperature is 49 degrees F, and the average frost-free 

season is 120 to 135 days. 

Typically, the upper part of the surface layer is reddish 

brown very stony loam about 6 inches thick, and the lower 

part is reddish brown gravelly loam about 4 inches thick. The 

subsoil is reddish brown very gravelly loam about 9 inches 

thick. The substratum is dark brown extremely gravelly loam 

about 9 inches thick. Basalt is at a depth of about 28 inches. 

Depth to bedrock ranges from 20 to 40 inches. 

Included in this unit are areas of McDaniel and Rock Creek 

soils and Rubble land. The percentage of included 

components varies from one area to another. 

Permeability of this Clint soil is moderate. Available water 

capacity is low. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Idaho fescue, and Sandberg 

bluegrass. The production of forage is limited by the low 

available water capacity and large stones. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass and Idaho fescue decreases and 

the proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

chemical treatment, and prescribed burning. Range 

seeding is a suitable practice if the range vegetation is in 

poor condition, but it is difficult because of stoniness. The 

unit should be seeded in fall using a drill. Adapted legumes 

and grasses should be seeded. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

23-Clint-Rubble land complex, 8 to 75 percent 

slopes. This map unit is on uplands. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

2,300 to 3,300 feet. The average annual precipitation is 15 

to 18 inches, the average annual air temperature is about 

49 degrees F, and the average frost-free season is 120 to 

135 days. 

This unit is 50 percent Clint very stony loam and 25 percent 

Rubble land. The components of this unit are so intricately 

intermingled that it was not practical to map them separately 

at the scale used. 

Included in this unit are about 10 percent McDaniel 

soils and about 15 percent Rock Creek soils. Also 

included are areas of Rock outcrop. Included areas 

make up about 25 percent of the total acreage. 

The Clint soil is moderately deep and well drained. It 

formed in loess and in residuum derived from basalt. 

Typically, the upper part of the surface layer is reddish 

brown very stony loam about 6 inches thick, and the lower 

part is reddish brown gravelly loam about 4 inches thick. 

The subsoil is reddish brown very gravelly loam about 9 

inches thick. The substratum is dark brown extremely 

gravelly loam about 9 inches thick. Basalt is at a depth of 

about 28 inches. Depth to bedrock ranges from 20 to 40 

inches. 

Permeability of the Clint soil is moderate. Available water 

capacity is low. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 

Rubble land is areas of basalt cobbles, stones, and 

boulders. It does not support vegetation. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on the Clint soil is mainly 

bluebunch wheatgrass, Idaho fescue, and Sandberg 

bluegrass. The production of forage is limited by the 

steepness of slope, large stones on the surface, and the 

areas of Rubble land. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass and Idaho fescue decreases and the proportion 

of less preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Brush control is largely limited to aerial applications of 

chemicals or prescribed burning because of the steepness 

of slope and the areas of Rubble land. Steepness of slope 

limits access by livestock and promotes overgrazing of the 

less sloping areas. Proper location of salt licks, stock water 

tanks, and fences promotes more uniform distribution of 

grazing. 

Range seeding on the Clint soil is a suitable practice if the 

range vegetation is in poor condition; however, seeding is 

difficult because of the large stones and the areas of Rubble 

land. The soil should be seeded in fall by broadcasting. 

Adapted legumes and grasses should be seeded. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

24-Cowiche loam, 2 to 5 percent slopes. This very

deep, well drained soil is on uplands. It formed in 
residuum derived from sandstone and has a mantle of 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,000 to 2,000 feet. The average 

annual precipitation is 9 to 12 inches, the average annual 

air temperature is about 49 degrees F, and the average 

frost-free season is 135 to 160 days. 

Typically, the surface layer is grayish brown and brown 

loam about 10 inches thick. The subsoil is brown, yellowish 

brown, and pale brown loam about 25 inches thick. The 

upper part of the substratum is pale brown very fine sandy 

loam about 10 inches thick, and the lower part to a depth of 

60 inches or more is brown loamy fine sand. In some areas 

weathered sandstone is at a depth of 40 to 60 inches. 

Included in this unit are about 10 percent Willis soils, 5 

percent Ritzville soils, and 5 percent Selah and Harwood 

soils. 

Permeability of this Cowiche soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is slow, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field crops and orchards, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain, grapes, hops, peas, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of 

water erosion. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to soil in this unit. The type of 

system used depends on the kind of crop grown. If furrow or 

corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of erosion can be 

minimized by keeping runs short. Sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of water erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. Pipe, ditch lining, or drop structures 

should be installed in irrigation ditches to facilitate irrigation 

and prevent excessive ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve organic matter content, help 

to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop 

residue on the surface reduce water erosion. Use of annual 

or perennial cover crops during the irrigation season 

reduces erosion in fields of hops and in orchards and 

vineyards (fig. 1). Using vegetated filter strips at the end 

of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. A plowpan develops in 

this soil; however, it can be broken by chiseling or 

subsoiling when the soil is dry. 

This unit is suited to homesite development. The main 

limitation is the moderate shrink-swell potential. The effects 

of shrinking and swelling can be minimized by 

using proper engineering designs and by backfilling with 

material that has low shrink-swell potential. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is the 

moderate permeability of the soil. Use of sandy backfill for 

the trench and long absorption lines helps to compensate 

for this limitation. Cutbanks are not stable and are subject 

to caving in. 

 This map unit is in capability subclass IIe, irrigated. 

25-Cowiche loam, 5 to 8 percent slopes. This very 

deep, well drained soil is on uplands. It formed in residuum 

derived from sandstone and has a mantle of loess. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,000 to 2,000 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is 49 degrees F, and the average frost-free 

season is 135 to 160 days. 

Typically, the surface layer is grayish brown and brown 

loam about 10 inches thick. The subsoil is brown, yellowish 

brown, and pale brown loam about 25 inches thick. The 

upper part of the substratum is pale brown very fine sandy 

loam about 10 inches thick, and the lower part to a depth of 

60 inches or more is brown loamy fine sand. In some areas 

weathered sandstone is at a depth of 40 to 60 inches. 

Included in this unit are about 10 percent Willis soils, 5 

percent Ritzville soils, and 5 percent Selah and Harwood 

soils. 

Permeability of this Cowiche soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain, grapes, peas, and tree fruit. Grasses and legumes 

are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of water erosion. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve organic matter content, 

help to maintain soil structure, improve the water 

infiltration rate, and reduce erosion. Using a cropping 

system that includes close-growing, high-residue crops in 

the rotation and maintaining crop 
Figure 1.-Irrigated orchard with a permanent cover crop on Cowiche loam, 2 to 5 percent slopes. 

residue on the surface also reduce erosion. A rotation of 

grain followed by alfalfa and grass commonly is used. Using 

cover crops in orchards and vineyards during the irrigation 

season reduces erosion. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. 

This unit is suited to homesite development. The main 

limitation is the moderate shrink-swell potential. The effects 

of shrinking and swelling can be minimized by using proper 

engineering designs and by backfilling excavations with 

material that has low shrink-swell potential. Dustiness can be 

a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is 

moderate permeability. Use of sandy backfill for the trench 

and long absorption lines helps to compensate 

for this limitation. Cutbanks are not stable and are 

subject to caving in. 

This map unit is in capability subclass Ille, irrigated. 

26-Cowiche loam, 8 to 15 percent slopes. This very 

deep, well drained soil is on uplands. It formed in residuum 

derived from sandstone and has a mantle of loess. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,000 to 2,000 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 135 to 160 days. 

Typically, the surface layer is grayish brown and brown 

loam about 10 inches thick. The subsoil is brown, yellowish 

brown, and pale brown loam about 25 inches thick. The 

upper part of the substratum is pale brown very fine sandy 

loam about 10 inches thick, and the lower part to a depth of 

60 inches or more is brown 
loamy sand. In some areas weathered sandstone is at a 

depth of 40 to 60 inches. 

Included in this unit are about 10 percent Willis soils, 5 

percent Ritzville soils, 5 percent Selah and Harwood soils, 

and areas of Cowiche loam that has slopes of less than 8 

percent. 

Permeability of this Cowiche soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. A cover crop is grown in orchards. Grass and 

legumes are grown for hay, pasture, or seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and 

drip irrigation systems are suited to the soil in this unit.

Use of these systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of water erosion. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain soil structure, and improve the water 

infiltration rate. Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces water 

erosion. A rotation of grain followed by alfalfa and grass 

commonly is used. Use of annual or perennial cover crops in 

orchards and vineyards during the irrigation season reduces 

erosion. A plowpan develops in this soil; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding early and 

using stubble mulch tillage. Use of terraces and 

stripcropping, either singly or in combination, may be 

needed. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be 

shaped and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and Idaho fescue. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the 

proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, and chemical treatment. Seeding is a suitable 

practice if the range vegetation is in poor 

condition. The unit should be seeded in fall using a drill. 

Adapted legumes and grasses should be seeded. 

This unit is suited to homesite development. The main 

limitations are the moderate shrink-swell potential and 

steepness of slope. The effects of shrinking and swelling 

can be minimized by using proper engineering designs and 

by backfilling excavations with material that has low shrinkswell potential. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

the moderate permeability of the soil and steepness of 

slope. Use of sandy backfill for the trench and long 

absorption lines helps to compensate for the moderate 

permeability. Slope can promote lateral seepage and 

surfacing of effluent in downslope areas. Absorption lines 

should be installed on the contour. Cutbanks are not stable 

and are subject to caving in. 

This map unit is in capability subclasses IVe, irrigated, and 

Ille, nonirrigated. 

27-Cowiche loam, 15 to 30 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

residuum derived from sandstone and has a mantle of 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,000 to 2,000 feet. The average 

annual precipitation is 9 to 12 inches, the average annual 

air temperature is about 49 degrees F, and the average 

frost-free season is 135 to 160 days. 

Typically, the surface layer is grayish brown and brown 

loam about 10 inches thick. The subsoil is brown, yellowish 

brown, and pale brown loam about 25 inches thick. The 

upper part of the substratum is pale brown very fine sandy 

loam about 10 inches thick, and the lower part to a depth of 

60 inches or more is brown loamy fine sand. In some areas 

weathered sandstone is at a depth of 40 to 60 inches. 

Included in this unit are about 5 percent Willis soils, 10 

percent Ritzville soils, and 5 percent Selah and Harwood 

soils. 

Permeability of the Cowiche soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or

more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for irrigated and nonirrigated field and 

orchard crops, for wildlife habitat, and as rangeland and 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. A cover crop is grown in orchards. Grasses and 

legumes are grown for hay, pasture, or seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of water 

erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, 
applications of irrigation water should be adjusted to the 

available water capacity and the crop needs. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. 

Perennial cover crops are needed in orchards and vineyards 

to reduce erosion. A plowpan develops in this soil; however, 

it can be broken by chiseling or subsoiling when the soil is 

dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion is reduced if fall grain is seeded early and 

stubble mulch tillage is used. Seeding early in fall, either on 

the contour or across the slope, slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Divided-slope farming and stripcropping are effective 

in reducing erosion. Drop structures are needed in places to 

control the flow of runoff in waterways. Waterways should be 

shaped and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and Idaho fescue. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, and chemical treatment. Seeding is a suitable 

practice if the range vegetation is in poor condition. The 

unit should be seeded in fall using a drill. Adapted legumes 

and grasses should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is steepness of slope. Dustiness can be a 

problem during construction on large building sites; therefore, 

these sites should be disturbed as little as possible. This unit 

should be seeded to reduce erosion and soil slippage. 

The main limitation for septic tank absorption fields is 

steepness of slope, which can promote lateral seepage and 

surfacing of effluent in downslope areas. Cutbanks are not 

stable and are subject to caving in. 

This map unit is in capability subclass IVe, irrigated and 

nonirrigated. 

28-Cowiche-Rock Creek complex, 5 to 15 percent 

slopes. This map unit is on uplands. The native vegetation 

is mainly grasses, forbs, and shrubs. Elevation is 1,500 to 

2,400 feet. The average annual precipitation is about 9 to 12 

inches, the average annual air temperature is about 49 

degrees F, and the frost-free season is about 135 to 160 

days. 

This unit is about 50 percent Cowiche loam and about 30 

percent Rock Creek very stony silt loam. The Cowiche soil is 

on mounds, and the Rock Creek soil is in areas between the 

mounds. The components of this unit 

are so intricately intermingled that it was not practical to 

map them separately at the scale used. 

Included in this unit are areas of Simcoe, Clint, 

Harwood, and Gorst soils. Also included are areas of 

Cowiche soils where about 25 percent of the surface 

layer has been removed by erosion. Included areas make 

up about 20 percent of the total acreage. 

The Cowiche soil is very deep and well drained. It formed 

in residuum derived from sandstone and has a mantle of 

loess. Typically, the surface layer is grayish brown and 

brown loam about 10 inches thick. The subsoil is brown, 

yellowish brown, and pale brown loam about 25 inches thick. 

The upper part of the substratum is pale brown very fine 

sandy loam about 10 inches thick, and the lower part to a 

depth of 60 inches or more is brown loamy fine sand. In 

some areas weathered sandstone is at a depth of 40 to 60 

inches. 

Permeability of the Cowiche soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water erosion 

is moderate. 

The Rock Creek soil is very shallow and well drained. It 

formed in loess and in residuum derived from basalt. 

Typically, the surface layer is grayish brown very stony silt 

loam about 2 inches thick. The subsoil is grayish brown and 

brown very cobbly clay about 8 inches thick. Basalt is at a 

depth of about 10 inches. Depth to basalt ranges from 8 to 

15 inches. 

Permeability of the Rock Creek soil is moderately slow. 

Available water capacity is low. Effective rooting depth is 

8 to 15 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation of the Cowiche soil is 

mainly bluebunch wheatgrass and Idaho fescue. The 

potential native vegetation of the Rock Creek soil is mainly 

stiff sagebrush, Sandberg bluegrass, and eriogonum. The 

main limitations for the production of forage on the Rock 

Creek soil are depth to rock and low available water 

capacity. If the range is overgrazed, the proportion of 

preferred forage plants such as stiff sagebrush and 

Sandberg bluegrass decreases and the proportion of 

less preferred forage plants such as forbs and annual 

grasses increases. 

Areas of the Cowiche soil that are heavily infested with 

undesirable vegetation can be improved by such methods as 

chaining, railing, beating, and chemical treatment. Care 

should be taken during brush control to disturb the Rock 

Creek soil as little as possible. 

Range seeding on the Rock Creek soil is not feasible 

because of low available water capacity and depth to rock. 

Proper range use and periodic rest are the most effective 

methods of range management and erosion control. Range 

seeding on the Cowiche soil is a suitable practice if the 

range vegetation is in poor condition. The soil should be 

seeded in fall using a drill. Adapted legumes and grasses 

should be seeded. 
This map unit is in capability subclass VIs, 

non irrigated. 

29-Cryumbrepts, gently sloping. These very deep, well 

drained soils are on terraces. They formed in old mixed 

alluvium and volcanic ash. Slope is 0 to 10 percent. The 

native vegetation is mainly conifers, grasses, forbs, and 

shrubs. Elevation is 4,700 to 5,200 feet. The average annual 

precipitation is 30 to 50 inches, the average annual air 

temperature is about 41 degrees F, and the average length 

of the growing season, at 28 degrees F, as 100 to 170 days. 

No single profile of Cryumbrepts is typical, but one 

commonly observed in the survey area is covered with a 

mat of partially decomposed organic material about 1 1/2 

inches thick. The surface layer is brown loam about 19 

inches thick. The subsoil is brown loam about 8 inches thick. 

The upper part of the substratum is yellowish brown loam 

about 12 inches thick, and the lower part to a depth of 60 

inches or more is yellowish brown sandy loam. 

Included in this unit are 10 percent Aquic Cryandepts 

along streams and in depressional areas and about 5 

percent Naxing soils in convex areas near the border of the 

unit. 

Permeability of these Cryumbrepts is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is slight. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Lodgepole pine, western larch, and grand fir are the main 

woodland species on this unit. Among the trees of limited 

extent are subalpine fir and Engelmann spruce. On the basis 

of a 100-year site curve, the mean site index is 89 for 

lodgepole pine. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for lodgepole pine is about 100 cubic 

feet per acre at 100 years of age. On the basis of a 50-year 

site curve, the mean site index is 50 for western larch. Yield 

tables for normal, even-aged, unmanaged stands indicate 

that the mean annual increment at culmination for western 

larch trees 0.6 inch in diameter and larger at 70 years of age 

is 63 cubic feet per acre. The mean annual increment for 

trees 7.6 inches in diameter and larger at 80 years of age is 

50 cubic feet per acre. However, the typical basal area of 

stands on this unit is about 105 percent that of normal 

stands, and the total yield is correspondingly higher. 

Snowpack hinders the use of equipment on this unit and 

limits access in winter. Unsurfaced roads and skid trails are 

soft when wet, and they may be impassable during spring 

runoff or in rainy periods. Use of wheeled and tracked 

equipment when the soil in this unit is wet produces ruts, 

compacts the soil, and damages tree roots. Logging roads 

require suitable surfacing for year 

round use. Rock for road construction is not readily 

available on this unit. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by lodgepole pine and 

western larch occurs readily. 

The common forest understory plants are lupine, yarrow, 

and strawberry. The crown density in the areas where the 

woodland site index was measured is 35 percent. This unit is 

suited to grazing and browsing. It has few limitations for the 

production of forage. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This map unit is in capability subclass VIe, 

nonirrigated. 

30-Darland stony loam, 45 to 75 percent slopes. 

This very deep, well drained soil is on south-facing 

mountainsides. It formed in colluvium derived from basalt. 

The native vegetation is mainly grasses, scattered trees, 

forbs, and shrubs. Elevation is 5,000 to 6,900 feet. The 

average annual precipitation is 25 to 45 inches, the 

average annual air temperature is about 42 degrees F, and 

the average length of the growing season, at 28 degrees F, 

is 100 to 120 days. 

Typically, the upper part of the surface layer is dark 

yellowish brown stony loam about 8 inches thick, and the 

lower part is dark brown very gravelly loam and very cobbly 

loam about 23 inches thick. The subsoil is dark yellowish 

brown extremely cobbly loam about 12 inches thick. The 

substratum to a depth of 60 inches or more is dark yellowish 

brown extremely cobbly sandy loam. In some areas the 

surface layer is severely eroded, in some areas there are no 

stones in the surface layer, and in some areas basalt is at a 

depth of 20 to 60 inches. At the southern edge of the 

headwaters of Foundation Creek, the parent material is shale.

Included in this unit are areas of Naxing soils on 

benches; areas of extremely stony soils; small concave 

areas of soils that have slopes of 20 to 45 percent; and 

soils, on ridgetops, that have slopes of 5 to 20 percent. 

Included areas make up about 10 percent of the total 

acreage. 

Permeability of this Darland soil is moderately rapid. 

Available water capacity is moderate. Effective rooting 

depth is 60 inches or more. Runoff is very rapid, and the 

hazard of water erosion is very high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on this unit is mainly Idaho 

fescue, Cusick bluegrass, elk sedge, and mountain brome. 

The main limitations for the production of forage are 

steepness of slope and stones on the surface. Steepness of 

slope promotes overgrazing of the less sloping areas. If the 

range is overgrazed, the proportion of preferred forage plants 

such as Cusick bluegrass decreases and the proportion of 

less preferred forage 
plants such as cheatgrass and sagebrush increases. Brush 

control is largely limited to aerial application of chemicals or 

prescribed burning. Proper location of salt licks, stock water 

tanks, and fences improves the distribution of livestock 

grazing. Seeding is limited by stones on the surface and 

steepness of slope. 

This unit is poorly suited to livestock watering ponds and 

other water impoundments. Water tanks, springs, wells, or 

pipeline systems can be used to provide water for livestock.

This map unit is in capability subclass Vlls, 

nonirrigated. 

31-Darland-Rubble land complex, 45 to 75 percent 

slopes. This map unit is on mountainsides. Slope is 

dominantly about 60 percent. The native vegetation is 

mainly grasses, forbs, shrubs, and scattered trees. 

Elevation is 5,000 to 6,500 feet. The average annual 

precipitation is 25 to 45 inches, the average annual air 

temperature is about 42 degrees F, and the average 

length of the growing season, at 28 degrees F, is 100 to 

120 days. 

This unit is about 55 percent Darland stony loam and 

about 35 percent Rubble land. The Darland soil is in long, 

irregularly shaped areas, and Rubble land is talus fans 

on mountain toe slopes below areas of Rock outcrop. The 

components of this unit are so intricately intermingled that 

it was not practical to map them separately at the scale 

used. 

Included in this unit are about 5 percent Naxing soils and 

Aquic Cryandepts on benches and about 10 percent areas of

Rock outcrop, severely eroded soils, and Darland soils that 

have slopes of 30 to 45 percent. The percentage varies 

from one area to another. 

The Darland soil is very deep and well drained. It formed 

in colluvium derived from basalt. Typically, the upper part of 

the surface layer is dark yellowish brown stony loam about 8 

inches thick. The lower part is dark brown very gravelly loam 

and very cobbly loam about 23 inches thick. The subsoil is 

dark yellowish brown extremely cobbly loam about 12 

inches thick. The substratum to a depth of 60 inches or 

more is dark yellowish brown extremely cobbly sandy 

loam. In some areas the surface layer does not have 

stones. 

Permeability of the Darland soil is moderately rapid. 

Available water capacity is moderate. Effective rooting depth 

is 60 inches or more. Runoff is very rapid, and the hazard of 

water erosion is very high. 

Rubble land is areas of cobbles, stones, and boulders. It is 

mostly free of vegetation. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on the Darland soil is 

mainly Idaho fescue, Cusick bluegrass, elk sedge, and 

mountain brome. The main limitations for the production of 

forage are steepness of slope, large stones in the surface 

layer, and areas of Rubble land. Steepness of slope 

promotes overgrazing of the less sloping areas. If 

the range is overgrazed, the proportion of preferred forage 

plants such as Cusick bluegrass decreases and the 

proportion of less preferred forage plants such as 

sagebrush and cheatgrass increases. Brush control is 

limited mainly to aerial application of chemicals or 

prescribed burning. Proper location of salt licks, stock water 

tanks, and fences improves the distribution of livestock 

grazing. Seeding is limited by very steep slopes and the 

areas of Rock outcrop and Rubble land. 

This unit is poorly suited to livestock watering ponds and 

other water impoundments. Water tanks, springs, -

wells, and 

pipeline systems can be used to provide water for livestock. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

32-Esquatzel silt loam, 0 to 2 percent slopes. This 

very deep, well drained soil is on flood plains dissected by 

intermittent and perennial streams. It formed in silty alluvium. 

The native vegetation is grasses, forbs, and shrubs. Elevation 

is 650 to 1,500 feet. The average annual precipitation is 6 to 

10 inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 130 to 160 

days. 

Typically, the surface layer is brown silt loam about 17 

inches thick. The underlying material to a depth of 60 inches 

or more is pale brown silt loam. In some areas the surface 

layer is fine sandy loam, in some areas the soil is stratified 

with thin lenses of sandy loam, and in some areas very 

gravelly loamy sand is at a depth of 36 inches or more. 

Included in this unit are small areas of Willis, Outlook, 

Warden, Umapine, and Selah soils. 

Permeability of this Esquatzel soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is very slow. This unit is subject to rare 

periods of flooding. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are asparagus, corn, grain, grapes, hops, mint, peas, and 

tree fruit. Grasses and legumes are grown for hay, pasture, 

and seed. 

This unit has few limitations for irrigated crops. Furrow, 

corrugation, drip, and sprinkler irrigation systems are suited 

to the soil in this unit. The type of system used depends on 

the kind of crop grown. If surface irrigation systems are 

used, the risk of erosion can be minimized by keeping runs 

short. Use of sprinkler or drip irrigation permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of water erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

rate of application of water should be reduced accordingly 

to help control runoff, erosion, and the production of 

sediment. To avoid loss of water and 
leaching of plant nutrients from overirrigation, applications of 

irrigation water should also be adjusted to the available 

water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve organic matter content, help 

to maintain tilth, and improve the infiltration rate. A plowpan 

develops in this soil; however, it can be broken by chiseling 

or subsoiling when the soil is dry. Using vegetated filter 

strips at the end of rows or using sediment ponds, or both, 

reduces the volume of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is the hazard of flooding. Dikes and channels that 

have outlets to bypass floodwater can be used to protect 

buildings and onsite sewage disposal systems from 

flooding. Dustiness can be a problem during construction on 

large building sites; therefore, these sites should be 

disturbed as little as possible. 

This map unit is in capability class I, irrigated. 

33-Esquatzel silt loam, 2 to 5 percent slopes. This 

very deep, well drained soil is on flood plains that are 

dissected by intermittent streams. It formed in silty alluvium. 

The native vegetation is grasses, forbs, and shrubs. 

Elevation is 650 to 1,500 feet. The average annual 

precipitation is 6 to 10 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 160 days. 

Typically, the surface layer is brown silt loam about 17 

inches thick. The underlying material to a depth of 60 inches 

or more is pale brown silt loam. In some areas the surface 

layer is fine sandy loam, and in some areas the soil is 

stratified with thin lenses of fine sandy loam. 

Included in this unit are small areas of Warden, 

Quincy, Willis, Scoon, Outlook, Finley, and Selah 

soils and areas of Esquatzel soils that have slopes of less 

than 2 percent. 

Permeability of this Esquatzel soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is slow, and the hazard of water erosion is 

moderate. This unit is subject to rare periods of flooding. 

This unit is used for irrigated and nonirrigated field and 

orchard crops, for wildlife habitat, and as rangeland and 

homesites. The main irrigated crops are asparagus, 

corn, grain, grapes, hops, mint, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and seed.

The main limitation for irrigated crops is the hazard of 

water erosion. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. If furrow 

or corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of erosion can be 

minimized by keeping runs short. Use of sprinkler or drip 

irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of water erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

rate of application of water should be reduced accordingly to 

help control runoff, erosion, and the production of sediment. 

To avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Use of minimum tillage and return of crop residue to 

the soil help to maintain or improve organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. 

Growing mint in meadows rather than in rows greatly 

reduces water erosion. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. A plowpan develops in 

this soil; however, it can be broken by chiseling or subsoiling 

when the soil is dry. 

The main limitations for nonirrigated crops are the low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. 

Erosion can be reduced by seeding fall grain early, 

stubble mulching, and shaping waterways and seeding them 

to perennial grass. Drop structures may be needed in a few 

places to stabilize the flow of runoff in waterways. 

The potential native vegetation on this unit is mainly 

basin wildrye, bluebunch wheatgrass, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, and chemical treatment. Range seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is the hazard of flooding. Dikes-and channels that 

have outlets to bypass floodwater can be used to protect 

buildings and onsite sewage disposal systems from 

flooding. Dustiness can be a problem 
during construction on large building sites; therefore, 

these sites should be disturbed as little as possible. 

This map unit is in capability subclasses lIe, irrigated, 

and llle, nonirrigated. 

34-Fiander silt loam. This very deep, artificially drained 

soil is on flood plains. It formed in alluvium. Slope is 0 to 3 

percent, but it is dominantly about 1 percent. The native 

vegetation is mainly alkali-tolerant grasses, forbs, and 

shrubs. Elevation is 700 to 900 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is moderately alkaline, 

grayish brown silt loam about 2 inches thick. The subsoil is 

strongly alkaline and very strongly alkaline, brown and pale 

brown silty clay loam about 23 inches thick. The upper part 

of the substratum is strongly alkaline, pale brown silt loam 

about 25 inches thick, and the lower part to a depth of 60 

inches or more is mildly alkaline, brown loamy very fine sand.

Included in this unit are small areas of Umapine, 

Kittitas, and Toppenish soils and areas of 

undrained, salt-affected Fiander soils. 

Permeability of this Fiander soil is slow. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal water table that is at a depth of 24 to 36 inches 

from June to December. Runoff is very slow. This unit is 

subject to rare periods of flooding. 

This unit is used for irrigated crops, as rangeland, for 

wildlife habitat, and as homesites. The main irrigated 

crops are corn, grain, and mint. Grasses and legumes 

are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is slow permeability. 

If the drainage systems are not maintained, the soil in this 

unit has a seasonal high water table during the irrigation 

season and a high content of sodium. Tile drainage can be 

used to lower the water table if a suitable outlet is available. 

Dikes are effective in diverting floodwater and reducing the 

risk of flooding. Deep-rooted crops are suited to areas where 

the natural drainage is adequate or where a drainage 

system has been installed and maintained. 

Reclamation may require addition of amendments such as 

gypsum, sulfur, or ferric sulfate to facilitate leaching. 

Furrow, corrugation, and sprinkler irrigation systems are 

suited to this soil. If surface irrigation systems are used, 

the risk of erosion can be minimized by keeping runs 

short. Use of sprinkler irrigation permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of water erosion. 

Cultivation prior to irrigation improves the water 

infiltration rate; however, the fine soil particles dislodged 

during cultivation are highly susceptible to water 

erosion. This makes the initial period of irrigation 

extremely critical. The water application rate should be 

reduced accordingly to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from overirrigation, applications of irrigation 

water should also be adjusted to the available water capacity 

and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to avoid compaction and to maintain or improve 

the organic matter content, improve the water infiltration 

rate, and help to maintain tilth. Using a cropping system that 

includes close-growing, high-residue crops in the rotation 

and maintaining crop residue on the surface reduce water 

erosion. Using vegetated filter strips at the end of rows or 

using sediment ponds, or both, reduces the volume of 

sediment in the tailwater. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. 

The potential native vegetation on this unit is mainly 

basin wildrye, inland saltgrass. and black greasewood. The 

main limitations for the production of forage are wetness 

because of the seasonal high water table and high sodium 

content. If the range is overgrazed, the proportion of less 

preferred forage plants such as black greasewood and 

inland saltgrass increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, and chemical treatment. Range seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted alkalitolerant plants should be seeded. 

The main limitations for homesite development are the 

hazard of flooding and soil wetness. Dikes and channels that 

have outlets to bypass floodwater can be used to protect 

buildings from flooding. Wetness can be reduced by 

installing drain tile around footings. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. Cutbanks are not stable and are subject to caving 

in. Mulching, fertilizing, and irrigating are needed to establish 

lawn grasses and other small seeded plants. 

The main limitations for septic tank absorption fields are 

the hazard of flooding, soil wetness, and slow permeability. 

Flooding can be controlled only by the use of major flood 

control structures. Slow permeability and the seasonal high 

water table increase the possibility of failure of septic tank 

absorption fields. Use of sandy backfill for the trench and 

long absorption lines helps to compensate for the slow 

permeability. 

This map unit is in capability subclasses IVw, irrigated, and 

Vlw, nonirrigated. 

35-Finley fine sandy loam, 0 to 5 percent slopes. 

This very deep, well drained soil is on terraces and alluvial 

fans. It formed in old alluvium. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 800 to 1,400 

feet. The average annual precipitation is 6 to 9 inches, the 

average annual air 
temperature is about 50 degrees F, and the average 

frost-free season is 135 to 180 days. 

Typically, the upper part of the surface layer is brown fine 

sandy loam about 4 inches thick, and the lower part is brown 

sandy loam about 10 inches thick. The subsoil is yellowish 

brown very gravelly loam about 16 inches thick. The 

substratum to a depth of 60 inches or more is yellowish 

brown extremely gravelly sand. In some areas the surface 

layer is cobbly. 

Included in this unit is areas of Quincy soils. 

Permeability of this Finley soil is moderately rapid above 

the substratum and very rapid through it. Available water 

capacity is low. Effective rooting depth is 60 inches or more. 

Runoff is slow, and the hazard of water erosion is slight. The 

hazard of soil blowing is high. 

 This unit is used as rangeland and for wildlife habitat. 

 The potential native vegetation is mainly bluebunch 

wheatgrass, needleandthread, Thurber needlegrass, and 

big sagebrush. The main limitations for the production of 

forage are low available water capacity and the hazard of soil 

blowing. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as annual forbs and big sagebrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, and chemical treatment. Seeding is a suitable 

practice if the range vegetation is in poor condition. This unit 

should be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This map unit is in capability subclass VIe, 

nonirrigated. 

36-Finley cobbly fine sandy loam, 0 to 5 percent 

slopes. This very deep, well drained soil is on terraces and 

alluvial fans. It formed in old alluvium. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 800 to 1,400 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the upper part of the surface layer is brown 

cobbly fine sandy loam about 4 inches thick. The lower 

part is brown sandy loam about 10 inches thick. The 

subsoil is yellowish brown very gravelly loam about 16 

inches thick. The substratum to a depth of 60 inches or 

more is yellowish brown extremely gravelly sand. In some 

areas the surface layer is not cobbly. 

Included in this unit are areas of Quincy soils. 

Permeability of this Finley soil is moderately rapid above 

the substratum and very rapid through it. Available water 

capacity is low. Effective rooting depth is 60 inches or more. 

Runoff is slow, and the hazard of water erosion is slight. The 

hazard of soil blowing is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass, needIeandthread, Thurber needlegrass, and big 

sagebrush. The main limitations for the production of forage 

are low available water capacity and the hazard of soil 

blowing. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as annual forbs and big sagebrush increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as chemical 

treatment and prescribed burning. Seedbed preparation is 

difficult because of large stones. This unit should be seeded 

in fall when moisture conditions are optimal. A drill should 

be used. Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass Vle, 

nonirrigated. 

37-Finley silt loam, 0 to 2 percent slopes. This very 

deep, well drained soil is on terraces and alluvial fans. It 

formed in old alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 600 to 1,300 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 50 degrees F, 

and the average frost-free season is 135 to 180 days. 

Typically, the surface layer is brown silt loam about 12 

inches thick. The subsoil is yellowish brown very gravelly 

loam about 18 inches thick. The substratum to a depth of 60 

inches or more is yellowish brown extremely gravelly sand. In 

some areas the surface layer is sandy loam. 

Included in this unit are small areas of Scooteney, 

Scoon, and Burke soils. 

Permeability of this Finley soil is moderately rapid above 

the substratum and very rapid through it. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is very slow, and the hazard of water erosion is 

slight. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are grain, 

grapes, hops, mint, and peas. Grasses and legumes are 

grown for hay, pasture, and seed. 

The main limitation for irrigated crops is moderate 

available water capacity. Furrow, corrugation, drip, and 

sprinkler irrigation systems are suited to the soil in this 

unit. The type of system used depends on the kind of crop 

grown. If surface irrigation systems are used, the risk of 

erosion can be minimized by keeping runs short. Use of 

sprinkler or drip irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of water erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely 
critical. The water application rate should be reduced 

accordingly to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from overirrigation, applications of irrigation 

water should also be adjusted to the available water 

capacity and the crop needs. 

Use of minimum tillage and return of crop residue to 

the soil help to maintain or improve organic matter 

content, improve infiltration, and help to maintain tilth. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue 

on the surface reduce water erosion. Using vegetated 

filter strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. 

This unit is well suited to homesite development. It has 

few limitations. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Cutbanks are not 

stable and are subject to caving in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage from 

onsite sewage disposal systems. 

This map unit is in capability subclass Ills, irrigated. 

38-Finley silt loam, 2 to 5 percent slopes. This very 

deep, well drained soil is on terraces and alluvial fans. It 

formed in old alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 600 to 1,300 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 180 days. 

Typically, the surface layer is brown silt loam about 12 

inches thick. The subsoil is yellowish brown very gravelly 

loam about 18 inches thick. The substratum to a depth of 60 

inches or more is yellowish brown extremely gravelly sand. 

Included in this unit are small areas of Burke, 

Scooteney, and Scoon soils and areas of Finley soils that 

have slopes of more than 5 percent. 

Permeability of this Finley soil is moderately rapid above 

the substratum and very rapid through it. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is slow, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are grain, 

grapes, hops, mint, and peas. Grasses and legumes 

are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are moderate 

available water capacity and the hazard of water erosion. 

Furrow, corrugation, drip, and sprinkler irrigation 

systems are suited to the soil in this unit. The type of 

system used depends on the kind of crop grown. If furrow or

corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of water erosion 

can be minimized by keeping runs short. Use of sprinkler 

and drip irrigation permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of water 

erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to erosion. This makes the 

initial period of irrigation extremely critical. The water 

application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and reduce ditch 

erosion.

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. 

Growing mint in meadows rather than in rows greatly 

reduces water erosion. Use of annual or perennial cover 

crops during the irrigation season reduces erosion in fields 

of hops, in orchards, and in vineyards. Using vegetated filter 

strips at the end of rows or using sediment ponds, or both, 

reduces the volume of sediment in the tailwater. 

This unit is well suited to homesite development. It has 

few limitations. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Cutbanks are not 

stable and are subject to caving in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage 

from onsite sewage disposal systems. 

This map unit is in capability subclass Ille, irrigated. 

39-Finley silt loam, 5 to 8 percent slopes. This very 

deep, well drained soil is on terraces and alluvial fans. It 

formed in old alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 600 to 1,300 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 50 degrees F, 

and the average frost-free season is 135 to 180 days. 

Typically, the surface layer is brown silt loam about 12 

inches thick. The subsoil is yellowish brown very gravelly 

loam about 18 inches thick. The substratum to a depth 
of 60 inches or more is yellowish brown extremely 

gravelly sand. 

Included in this unit are small areas of Burke, 

Scooteney, and Scoon soils. 

Permeability of this Finley soil is moderately rapid above 

the substratum and very rapid through it. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are grain, 

grapes, and peas. Grasses and legumes are grown for hay, 

pasture, and seed. 

The main limitations for irrigated crops are moderate 

available water capacity, steepness of slope, and the hazard 

of water erosion. Sprinkler and drip irrigation systems are 

suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. Use of these irrigation 

systems permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of water erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to erosion. This makes the 

initial period of irrigation extremely critical. The water 

application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to 

the soil help to maintain or improve organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Growing cover crops reduces erosion in orchards 

and vineyards. 

This unit is well suited to homesite development. It has few 

limitations. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. Cutbanks are not stable and 

subject to caving in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage 

from onsite sewage disposal systems. 

This map unit is in capability subclass Ille, irrigated. 

40-Finley silt loam, 8 to 15 percent slopes. This 

very deep, well drained soil is on terraces and alluvial 

fans. It formed in old alluvium. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 600 to 

1,300 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 

180 days. 

Typically, the surface layer is brown silt loam about 12 

inches thick. The subsoil is yellowish brown very gravelly 

loam about 18 inches thick. The substratum to a depth 

of 60 inches or more is yellowish brown extremely 

gravelly sand. 

Included in this unit are small areas of Burke, 

Scooteney, and Scoon soils and areas of Finley soils 

that have slopes of 15 to 30 percent. 

Permeability of this Finley soil is moderately rapid 

above the substratum and very rapid through it. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are grain and 

grapes. Grasses and legumes are grown for hay, pasture, 

and seed. 

The main limitations for irrigated crops are the moderate 

available water capacity, steepness of slope, and the hazard 

of water erosion. Sprinkler and drip irrigation systems are 

suited to the soil in this unit. Use of these systems permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to erosion. This makes the 

initial period of irrigation extremely critical. The water 

application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue 

on the surface reduce water erosion. Use of annual or 

perennial cover crops is needed in orchards and vineyards 

to reduce erosion. A rotation of grain followed by alfalfa and 

grass commonly is used. 

This unit is suited to homesite development. The main 

limitation is steepness of slope. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. The unit should be seeded to reduce erosion and 

slippage of the soil. Cutbanks are not stable and subject to 

caving in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage 
from onsite sewage disposal systems. Slope can cause 

lateral seepage and surfacing of effluent in downslope 

areas. Absorption lines should be installed on the contour. 

This map unit is in capability subclass IVe, irrigated. 

41-Gorskel very stony loam, 0 to 25 percent slopes. 

This shallow, well drained soil is on terraces and foot slopes. 

It formed in loess and old alluvium. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,200 to 3,000 

feet. The average annual precipitation is 10 to 12 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 120 to 150 days. 

Typically, the surface layer is brown very stony loam 

about 5 inches thick. The upper part of the subsoil is 

yellowish brown gravelly loam about 3 inches thick, and the 

lower part is dark yellowish brown very gravelly clay loam 

about 5 inches thick. A hardpan is at a depth of about 13 

inches. Depth to the hardpan ranges from 9 to 15 inches. In 

some areas the surface layer is stony silt loam. 

Included in this unit are areas of Gorst, Harwood, 

Rock Creek, and Taneum soils. 

Permeability of this Gorskel soil is moderately slow 

above the hardpan and very slow through it. Available 

water capacity is low. Effective rooting depth is 9 to 15 

inches. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used as rangeland, for wildlife habitat, and as 

homesites. 

The potential native vegetation is mainly stiff sagebrush, 

Sandberg bluegrass, and eriogonum. The main limitations for 

the production of forage are large stones on the surface, 

low available water capacity, and low annual precipitation. If 

the range is overgrazed, the proportion of preferred forage 

plants such as stiff sagebrush and Sandberg bluegrass 

decreases and the proportion of less preferred forage plants 

such as forbs and annual grasses increases. 

This unit is poorly suited to homesite development. The 

main limitations are the shallow depth to the hardpan and 

steepness of slope in areas where slopes are more than 15 

percent. The pan hinders excavation. Access roads must be 

designed to control surface runoff and help stabilize cut 

slopes. 

The main limitation for septic tank absorption fields is the 

depth to the cemented pan, which limits the capacity of the 

absorption field. Use of long absorption lines helps to 

compensate for this limitation. Absorption lines should be 

installed on the contour. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

42-Gorskel-Harwood complex, 0 to 25 percent 

slopes. This map unit is on uplifted terraces. The native 

vegetation is mainly forbs and shrubs. Elevation is 1,200 

to 2,300 feet. The average annual precipitation is 10 to 12 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

This unit is about 50 percent Gorskel very stony loam 

and about 40 percent Harwood loam. The Harwood soil is 

on mounds, and the Gorskel soil is in areas between the 

mounds. The components of this unit are so intricately 

intermingled that it was not practical to map them 

separately at the scale used. 

Included in this unit are small areas of Gorst, Rock 

Creek, and Taneum soils. Included areas make up about 10 

percent of the total acreage. 

 The Gorskel soil is shallow and well drained. It formed in 

loess and old alluvium. Typically, the surface layer is brown 

very stony silt loam about 5 inches thick. The upper part of the 

subsoil is yellowish brown gravelly loamabout 3 inches thick, 

and the lower part is dark yellowish brown very gravelly clay 

loam about 5 inches thick. A hardpan is at a depth of about 

13 inches. Depth to the hardpan ranges from 9 to 15 inches. 

Permeability of the Gorskel soil is moderately slow 

above the hardpan and very slow through it. Available 

water capacity is low. Effective rooting depth is 9 to 15 

inches. Runoff is medium, and the hazard of water erosion 

is moderate. 

The Harwood soil is moderately deep and well drained. It 

formed in loess and old alluvium. Typically, the surface layer 

is grayish brown loam about 8 inches thick. The subsoil is 

brown loam about 18 inches thick. The substratum is brown 

gravelly loam about 4 inches thick. A hardpan is at a depth 

of about 30 inches. Depth to the hardpan ranges from 20 to 

40 inches. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation of the Gorskel soil is 

mainly stiff sagebrush, Sandberg bluegrass, and eriogonum. 

If the range plants on the Gorskel soil are overgrazed, the 

proportion of preferred forage plants such as stiff sagebrush 

and Sandberg bluegrass decreases and the proportion of 

less preferred forage plants such as forbs and annual 

grasses increases. The production of forage on the Gorskel 

soil is limited by depth to bedrock, large stones on the 

surface, and low available water capacity. The potential 

native vegetation of the Harwood soil is mainly bluebunch 

wheatgrass, Sandberg bluegrass, and big sagebrush. If the 

range plants on the Harwood soil are overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. 
Areas of the Harwood soil that are heavily infested with 

undesirable vegetation can be improved by such methods as 

chemical treatment and prescribed burning. Care should be 

taken during brush control to disturb the Gorskel soil as little 

as possible. Range seeding on the Harwood soil is a 

suitable practice if the range is in poor condition. The soil 

should be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

43-Gorst loam, 2 to 15 percent slopes. This well 

drained soil is on high, dissected terraces. It is shallow over 

a hardpan. It formed in loess and old alluvium. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

1,200 to 2,000 feet. The average annual precipitation is 8 to 

12 inches, and the average annual air temperature is about 

50 degrees F; and the average frost-free season is 135 to 

150 days. 

Typically, the surface layer is brown loam about 7 inches 

thick. The subsoil is pale brown and brown loam about 8 

inches thick. A hardpan is at a depth of about 15 inches. 

Depth to the hardpan ranges from 12 to 20 inches. In some 

areas the surface layer is cobbly, in some areas the subsoil 

is silty clay loam, and in some areas the soil is underlain by 

sandstone. 

Included in this unit are about 5 percent Harwood soils 

and 5 percent Rock Creek soils. 

Permeability of this Gorst soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 12 to 20 inches. Runoff is 

medium, and the hazard of water erosion is moderate. 

This unit is used for irrigated field and orchard crops and 

as rangeland, wildlife habitat, and homesites. The main 

irrigated crop is tree fruit. Grasses and legumes are grown 

for hay, pasture, and seed. A perennial cover crop is grown 

in orchards. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are suited to 

the soil in this unit. The type of system used depends on the 

kind of crop grown. Use of these systems permits the even, 

controlled application of irrigation water, reduces runoff, and 

minimizes the risk of erosion. The depth to the hardpan and 

steepness of slope make water management extremely 

important. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should be adjusted to the available water capacity, the water 

intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Use of perennial cover crops in orchards 

reduces erosion. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Thurber needlegrass, and Sandberg 

bluegrass. The production of forage is limited by the low 

available water capacity. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as sagebrush increases. Areas that are 

heavily infested with undesirable vegetation can be 

improved by such methods as chaining, railing, chemical 

treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the hardpan, which hinders 

excavation. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

depth to the hardpan, which limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclasses IVe, irrigated, and 

Vle, nonirrigated. 

44-Gorst loam, 15 to 30 percent slopes. This well 

drained soil is on high, dissected terraces. It is shallow over 

a hardpan. It formed in loess and old alluvium. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

1,200 to 2,000 feet. The average annual precipitation is 8 to 

12 inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typically, the surface layer is brown loam about 7 inches 

thick. The subsoil is pale brown and brown loam about 8 

inches thick. A hardpan is at a depth of about 15 inches. 

Depth to the hardpan ranges from 12 to 20 inches. In 

some areas the surface layer is cobbly, in some areas the 

subsoil is silty clay loam, and in some areas the soil is 

underlain by sandstone. 

Included in this unit are about 5 percent Harwood soils 

and about 10 percent Rock Creek soils. 

Permeability of this Gorst soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 12 to 20 inches. Runoff is 

rapid, and the hazard of water erosion is high. 

This unit is used for irrigated field and orchard crops and 

as rangeland, wildlife habitat, and homesites. The main 

irrigated crop is tree fruit. A perennial cover crop is grown in 

orchards. Grasses and legumes are grown for hay, pasture, 

or seed. 

The main limitations for irrigated crops are the depth to 

the hardpan, steepness of slope, and the hazard of 
water erosion. Sprinkler and drip irrigation systems are 

suited to the soil in this unit. Use of these systems permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to 

the available water capacity, the water intake rate, and the 

crop needs. Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces water 

erosion. Use of perennial cover crops is needed in orchards 

to reduce erosion. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Thurber needlegrass, and 

Sandberg bluegrass. The production of forage is limited by 

the low available water capacity. If the range is overgrazed, 

the proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as sagebrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are the depth to the hardpan and steepness 

of slope. The hardpan hinders excavation. Dustiness can be 

a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as possible.

The main limitations for septic tank absorption fields are 

depth to the hardpan and steepness of slope. The pan limits 

the capacity of the absorption fields. Use of long absorption 

lines helps to compensate for this limitation. Slope can cause 

lateral seepage and surfacing of effluent in downslope areas.

This map unit is in capability subclass Vle, irrigated and 

nonirrigated. 

45-Gorst cobbly loam, 0 to 25 percent slopes. This 

shallow, well drained soil is on high, dissected terraces. It 

formed in loess and old alluvium. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,200 to 

2,000 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown cobbly loam about 7 

inches thick. The subsoil is pale brown and brown loam 

about 8 inches thick. A hardpan is at a depth of about 15 

inches. Depth to the hardpan ranges from 12 to 20 inches. In 

some areas the surface layer is gravelly, in some areas the 

subsoil is silty clay loam, and in some areas the soil is 

underlain by sandstone. 

Included in this unit are areas of Gorskel, Harwood, 

Rock Creek, and Simcoe soils. 

Permeability of this Gorst soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

low. Effective rooting depth is 12 to 20 inches. Runoff is 

slow, and the hazard of water erosion is moderate. 

This unit is used for irrigated field and orchard crops, as 

rangeland, and for wildlife habitat. The main irrigated crops 

are permanent grasses and legumes and tree fruit. A 

perennial cover crop is grown in orchards. 

The main limitations for irrigated crops are the depth to 

the hardpan and steepness of slope. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. Using a cropping system that 

includes close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Growing perennial cover crops in orchards reduces 

erosion. Seedbed preparation is difficult, and removal of 

stones may be necessary. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Thurber needlegrass, and Sandberg 

bluegrass. The production of forage is limited by large 

stones on the surface and low available water capacity. If 

the range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass decreases and the 

proportion of less preferred forage plants such as bitterbrush 

increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

Use of equipment is difficult because of the cobbles. 

Removal of cobbles may be needed before seeding with a 

drill. Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass VIe, irrigated and 

nonirrigated. 

46-Harwood loam, 2 to 5 percent slopes. This well 

drained soil is on high, dissected terraces. It is moderately 

deep over a hardpan. It formed in loess and old alluvium. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,200 to 2,000 feet. The average annual 

precipitation is 8 to 12 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 150 days. 

Typically, the surface layer is grayish brown loam about 8 

inches thick. The subsoil is brown loam about 18 inches 

thick. The substratum is brown gravelly loam about 4 inches 

thick. A hardpan is at a depth of about 
30 inches. Depth to the hardpan ranges from 20 to 40 

inches. In some areas the soil is underlain by sandstone. 

Included in this unit are about 10 percent Selah soils, 10 

percent Gorst soils, and 5 percent Ritzville soils. 

Permeability of this Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is slow, and the hazard of water erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, and wildlife habitat. It is also used as 

rangeland and homesites. The main irrigated crops are 

grain, grapes, and tree fruit. Grasses and legumes are 

grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan and the hazard of water erosion. Furrow, 

corrugation, drip, and sprinkler irrigation systems are 

suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. If furrow or corrugation 

systems are used, runs should be on the contour or across 

the slope. The risk of erosion can be minimized by keeping 

runs short. Use of sprinkler or drip irrigation permits the 

even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. Pipe, 

ditch lining, or drop structures should be installed in irrigation 

ditches to facilitate irrigation and prevent excessive ditch 

erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop 

residue on the surface reduce water erosion. Using 

vegetated filter strips at the end of rows or using sediment 

ponds, or both, reduces the volume of sediment in the 

tailwater. Exposing the substratum when leveling fields 

should be avoided. Shallow cuts are feasible in some areas. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, and shaping waterways and 

seeding them to perennial grass. Seeding early in fall, 

either on the contour or across the slope, slows runoff and 

reduces erosion when the snow melts rapidly while the soil 

is still frozen. Drop structures are needed in a few places to 

stabilize the flow of runoff in waterways. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, big sagebrush, and Sandberg 

bluegrass. If the range is overgrazed, the proportion 

of preferred forage plants such as bluebunch 

wheatgrass 

decreases and the proportion of less preferred forage 

plants such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

plowing, beating, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the hardpan, which hinders 

excavation. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

depth to the hardpan. The pan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclass Ille, irrigated 

and nonirrigated. 

47-Harwood loam, 5 to 8 percent slopes. This well 

drained soil is on high, dissected terraces. It is moderately 

deep over a hardpan. It formed in loess and old alluvium. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,200 to 2,000 feet. The average annual 

precipitation is 8 to 12 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 150 days. 

Typically, the surface layer is grayish brown loam about 8 

inches thick. The subsoil is brown loam about 18 inches 

thick. The substratum is brown gravelly loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas the 

soil is underlain by sandstone. 

Included in this unit are about 10 percent Selah soils, 10 

percent Gorst soils, and 5 percent Ritzville soils. 

Permeability of this Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. Grasses and legumes are grown for hay, pasture, 

and seed. 

The main limitations for irrigated crops are the depth to the 

hardpan, the hazard of water erosion, and steepness of 

slope. Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water erosion. 

Sprinkler and drip irrigation systems are suited to the soil in 

this unit. The type of system used depends on the kind of 

crop grown. Use of these irrigation systems permits the 

even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of 
plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. 

The main limitation for nonirrigated crops is low annual 

precipitation. Because precipitation is not sufficient for 

annual cropping, a cropping system that includes winter 

wheat and summer fallow is most suitable. Erosion can be 

reduced by seeding early in fall, using stubble mulch tillage, 

and shaping waterways and seeding them to perennial 

grass. Seeding early in fall, either on the contour or across 

the slope, slows runoff and reduces erosion when the snow 

melts rapidly while the soil is still frozen. Drop structures are 

needed in a few places to stabilize the flow of runoff in 

waterways. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, big sagebrush, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

'decreases and the proportion of less preferred forage 

plants such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, and chemical treatment. Range seeding is a suitable 

practice if the range vegetation is in poor condition. The unit 

should be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the hardpan, which hinders 

excavation. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

depth to the hardpan, which limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclass Ille, irrigated 

and nonirrigated. 

48-Harwood loam, 8 to 15 percent slopes. This well 

drained soil is on high, dissected terraces. It is moderately 

deep over a hardpan. It formed in loess and old alluvium. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,200 to 2,000 feet. The average annual 

precipitation is 8 to 12 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 150 days. 

Typically, the surface layer is grayish brown loam about 8 

inches thick. The subsoil is brown loam about 18 inches 

thick. The substratum is brown gravelly loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas the 

soil is underlain by sandstone. 

Included in this unit are about 10 percent Selah soils, 5 

percent Gorst soils, and 5 percent Ritzville soils. 

Permeability of this Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 

inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. A cover crop is grown in orchards. Grasses and 

legumes are grown for hay, pasture, or seed. 

The main limitations for irrigated crops are depth to the 

hardpan, the hazard of water erosion, and steepness of 

slope. Sprinkler and drip irrigation systems are suited to the 

soil in this unit. Use of these systems permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water erosion. A 

crop rotation of grain followed by alfalfa and grass 

commonly is used. 

The main limitations for nonirrigated crops are the low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, a 

cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

early in fall and using stubble mulch tillage. Seeding early in 

fall, either on the contour or across the slope, slows runoff 

and reduces erosion when the snow melts rapidly while the 

soil is still frozen. Using level or gradient terraces and 

stripcropping, either singly or in combination, also reduce 

erosion. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, big sagebrush, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage 

plants such as big sagebrush and rabbitbrush 

increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, and chemical treatment. Seeding is a suitable 

practice if the range vegetation is in poor condition. The unit 

should be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is the depth to the hardpan, which hinders 

excavation. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

depth to the hardpan, which limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Absorption lines should be 
installed on the contour. Slope can promote lateral 

seepage and surfacing of the effluent in downslope 

areas. 

This map unit is in capability subclasses lVe, irrigated, 

and Ille, nonirrigated. 

49-Harwood loam, 15 to 30 percent slopes. This 

well drained soil is on high, dissected terraces. It is 

moderately deep over a hardpan. It formed in loess and old 

alluvium. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,000 feet. The average annual 

precipitation is 8 to 12 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 150 days. 

Typically, the surface layer is grayish brown loam about 8 

inches thick. The subsoil is brown loam about 18 inches 

thick. The substratum is brown gravelly loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas the 

soil is underlain by sandstone. 

Included in this unit are about 10 percent Selah soils, 5 

percent Gorst soils, and 5 percent Ritzville soils. 

Permeability of this Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

This unit is used for irrigated and nonirrigated crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are grapes and tree fruit. A cover crop is 

grown in orchards. Grasses and legumes are grown for hay, 

pasture, or seed. 

The main limitations for irrigated crops are depth to the 

hardpan, the hazard of water erosion, and steepness of 

slope. Sprinkler and drip irrigation systems are suited to the 

soil in this unit. Use of these systems permits the even, 

controlled application of water, reduces runoff, and minimizes 

the risk of erosion. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. Using a cropping 

system that includes close-growing, high-residue crops in the 

rotation reduces water erosion. Perennial cover crops are 

needed in orchards and vineyards to reduce erosion. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding early in 

fall and using stubble mulch tillage. Seeding early in fall, 

either on the contour or across the slope, slows runoff and 

reduces erosion when the snow melts rapidly while the soil 

is frozen. Divided-slope farming or stripcropping also 

reduces erosion. Drop structures are needed in places to 

control the flow 

of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, big sagebrush, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitations are the depth to the hardpan and steepness 

of slope. The pan hinders excavation. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields are 

the depth to the hardpan and steepness of slope. The 

hardpan limits the capacity of the absorption fields. Use of 

long absorption lines helps to compensate for this limitation. 

Slope can promote lateral seepage and surfacing of effluent 

in downslope areas. 

This map unit is in capability subclass IVe, irrigated 

and nonirrigated. 

50-Harwood-Burke-Wiehl silt loams, 2 to 5 percent 

slopes. This map unit is on uplands. The native vegetation is 

grasses, forbs, and shrubs. Elevation is 1,000 to 2,000 feet. 

The average annual precipitation is 6 to 10 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 170 days. 

This unit is about 30 percent Harwood silt loam, about 30 

percent Burke silt loam, and about 20 percent Wiehl silt 

loam. The components of this unit are so intricately 

intermingled that it was not practical to map them 

separately at the scale used. 

Included in this unit are areas of Selah, Gorst, and Scoon 

soils and areas of soils that have slopes of less than 2 

percent. Also included are areas of soils that have hardpan 

fragments scattered throughout the profile and on the 

surface. Included areas make up about 20 percent of the 

total acreage. 

The Harwood soil is well drained. It is moderately deep 

over a hardpan. It formed in loess and old alluvium. Typically, 

the surface layer is grayish brown silt loam about 8 inches 

thick. The subsoil is brown silt loam about 18 inches thick. 

The substratum is brown gravelly silt loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas the 

surface layer is very fine sandy loam. 
Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is slow, and the hazard of water erosion is moderate.

The Burke soil is well drained. It is moderately deep over a 

hardpan. It formed in loess. Typically, the surface layer is 

pale brown silt loam about 7 inches thick. The substratum is 

pale brown silt loam about 18 inches thick. A hardpan is at a 

depth of about 25 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the surface layer is very fine 

sandy loam. 

Permeability of the Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is slow, and the hazard of water erosion is moderate. 

The Wiehl soil is moderately deep and well drained. It 

formed in loess. Typically, the surface layer is grayish brown 

silt loam about 3 inches thick. The subsoil is brown and pale 

brown silt loam about 18 inches thick. The substratum is 

pale brown gravelly silt loam about 6 inches thick. Weakly 

cemented sandstone is at a depth of about 27 inches. 

Depth to sandstone or laminated sediment ranges from 20 

to 40 inches. In some areas the surface layer is very fine 

sandy loam. 

Permeability of the Wiehl soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 20 to 

40 inches. Runoff is slow, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated and nonirrigated crops, 

rangeland, homesites, and wildlife habitat. The main 

irrigated crops are grain, grapes, and tree fruit. Grasses 

and legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are the hazard of 

water erosion, depth to the hardpan in the Harwood and 

Burke soils, and depth to soft sandstone in the Wiehl soil. 

Furrow, corrugation, drip, and sprinkler irrigation 

systems are suited to the soils in this unit. The type of 

system used depends on the kind of crop grown. If furrow or 

corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of water erosion 

can be minimized by keeping runs short. Sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. To avoid 

loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Use of minimum tillage and return of crop residue to 

the soil help to maintain or improve the organic matter 

content and to maintain tilth. Using a cropping system 

that includes close-growing, high-residue crops in 

the rotation reduces water erosion. Using vegetated filter 

strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. 

Exposing the substratum when leveling fields should be 

avoided. Shallow cuts are feasible in some areas. 

The main limitations for nonirrigated crops are the low 

annual precipitation, the moderate available water capacity, 

and the hazard of water erosion. Because precipitation is 

not sufficient for annual cropping, a cropping system that 

includes winter wheat and summer fallow is most suitable. 

Erosion can be reduced by seeding fall grain early, stubble 

mulching, and shaping waterways and seeding them to 

perennial grass. Drop structures are needed in a few places 

to stabilize the flow of runoff in waterways. 

The potential native vegetation of the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, and big 

sagebrush. The potential native vegetation of the Burke soil 

is mainly bluebunch wheatgrass, Sandberg bluegrass and 

Thurber needlegrass. The potential native vegetation of the 

Wiehl soil is mainly bluebunch wheatgrass and 

needleandthread. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such practices as chaining, railing, 

beating, plowing, chemical treatment, and prescribed 

burning. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are depth to the hardpan in the Harwood 

and Burke soils and depth to soft sandstone in the Wiehl 

soil. The hardpan and sandstone hinder excavation. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

The main limitations for septic tank absorption fields are 

depth to the hardpan in the Harwood and Burke soils and 

depth to soft sandstone in the Wiehl soil. The hardpan and 

sandstone limits the capacity of the absorption fields. Use of 

long absorption lines helps to compensate for these 

limitations. 

This map unit is in capability subclasses Ille, irrigated, 

and IVe, nonirrigated. 

51-Harwood-Burke-Wiehl silt loams, 5 to 8 percent 

slopes. This map unit is on uplands. The native vegetation 

is grasses, forbs, and shrubs. Elevation is 1,000 to 2,000 

feet. The average annual precipitation is 6 to 10 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 170 days. 

This unit is about 30 percent Harwood silt loam, about 30 

percent Burke silt loam, and about 20 percent Wiehl silt 

loam. The components of this unit are so intricately 
intermingled that it was not practical to map them 

separately at the scale used. 

Included in this unit are areas of Gorst, Selah, and Scoon 

soils and areas of soils that have slopes of less than 5 

percent. Also included are areas of soils that have hardpan 

fragments scattered throughout the profile and on the 

surface. Included areas make up about 20 percent of the 

total acreage. 

The Harwood soil is well drained. It is moderately deep 

over a hardpan. It formed in loess and old alluvium. 

Typically, the surface layer is grayish brown silt loam about 

8 inches thick. The subsoil is brown silt loam about 18 

inches thick. The substratum is brown gravelly silt loam 

about 4 inches thick. A hardpan is at a depth of about 30 

inches. Depth to the hardpan ranges from 20 to 40 inches. 

In some areas the surface layer is very fine sandy loam. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. 

The Burke soil is well drained and it is moderately deep 

over a hardpan. It formed in loess. Typically, the surface 

layer is pale brown silt loam about 7 inches thick. The 

underlying material is pale brown silt loam about 18 inches 

thick. A hardpan is at a depth of about 25 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas 

the surface layer is very fine sandy loam. 

Permeability of the Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

The Wiehl soil is moderately deep and well drained. It 

formed in loess. Typically, the surface layer is grayish brown 

silt loam about 3 inches thick. The subsoil is brown and pale 

brown silt loam about 18 inches thick. The substratum is 

pale brown gravelly silt loam about 6 inches thick. Weakly 

cemented sandstone is at a depth of about 27 inches. 

Depth to sandstone or laminated sediment ranges from 20 

to 40 inches. In some areas the surface layer is very fine 

sandy loam. 

Permeability of the Wiehl soil is moderate above the 

sandstone and very slow through it. Available water 

capacity is moderate. Effective rooting depth is 20 to 40 

inches. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used for irrigated crops, rangeland, wildlife 

habitat, and homesites. The main irrigated crops are grain, 

grapes, and tree fruit. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope, the hazard of water erosion, depth to the hardpan in 

the Harwood and Burke soils, and depth to soft sandstone 

in the Wiehl soil. Sprinkler and drip 

irrigation systems are suited to the soils in this unit. The 

type of system used depends on the kind of crop grown. 

Use of these systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should be adjusted to the available water capacity and the 

crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. 

The potential native vegetation of the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, and 

big sagebrush. The potential native vegetation on the Burke 

soil is mainly bluebunch wheatgrass, Sandberg bluegrass, 

and Thurber needlegrass. The potential native vegetation of 

the Wiehl soil is mainly bluebunch wheatgrass and 

needleandthread. If the range is overgrazed, the proportion 

of preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are depth the hardpan in the Harwood and 

Burke soils and depth to soft sandstone in the Wiehl soil. The 

hardpan and soft sandstone hinder excavation. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

depth to the hardpan in the Harwood and Burke soils and 

depth to soft sandstone in the Wiehl soil. The hardpan and 

sandstone limit the capacity of the absorption fields. Use of 

long absorption lines helps to compensate for these 

limitations. 

This map unit is in capability subclass Ille, irrigated. 

52-Harwood-Burke-Wiehl silt loams, 8 to 15 percent 

slopes. This map unit is on uplands. The native vegetation 

is grasses, forbs, and shrubs. Elevation is 1,000 to 1,300 

feet. The average annual precipitation is 6 to 10 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 170 days. 

This unit is about 30 percent Harwood silt loam, about 30 

percent Burke silt loam, and about 20 percent Wiehl silt 

loam. The components of this unit are so intricately 
intermingled that it was not practical to map them 

separately at the scale used. 

Included in this unit are about 10 percent Selah soils, 5 

percent Ritzville soils, and 5 percent Scoon and Scooteney 

soils and areas of soils that have slopes of more than 15 

percent. Also included are areas of soils that have hardpan 

fragments scattered throughout the profile and on the 

surface and areas of soils that have laminated sediment at a 

depth of 20 to 40 inches. These included areas make up 

about 25 percent of the total acreage. 

The Harwood soil is well drained. It is moderately deep 

over a hardpan. It formed in loess and old alluvium. Typically, 

the surface layer is grayish brown silt loam about 8 inches 

thick. The subsoil is brown silt loam about 18 inches thick. 

The substratum is brown gravelly silt loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas the 

surface layer is very fine sandy loam. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

The Burke soil is well drained. It is moderately deep over a 

hardpan. It formed in loess. Typically, the surface layer is pale 

brown silt loam about 7 inches thick. The substratum is pale 

brown silt loam about 18 inches thick. A hardpan is at a 

depth of about 25 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the surface layer is very 

fine sandy loam. 

Permeability of the Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

The Wiehl soil is moderately deep and well drained. It 

formed in loess. Typically, the surface layer is grayish 

brown silt loam about 3 inches thick. The subsoil is brown 

and pale brown silt loam about 18 inches thick. The 

substratum is pale brown gravelly silt loam about 6 inches 

thick. Weakly cemented sandstone is at a depth of about 27 

inches. Depth to sandstone ranges from 20 to 40 inches. In 

some areas the surface layer is very fine sandy loam. 

Permeability of the Wiehl soil is moderate above the soft 

sandstone and very slow through it. Available water 

capacity is moderate. Effective rooting depth is 20 to 40 

inches. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, homesites, and wildlife 

habitat. The main irrigated crops are grain, grapes, 

and tree fruit. A cover crop is grown in orchards. Grasses 

and legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope, the hazard of erosion, depth to the hardpan in the 

Harwood and Burke soils, and depth to soft sandstone in 

the Wiehl soil. Sprinkler and drip irrigation systems are 

suited to the soils in this unit. Use of these systems permits 

the even, controlled application of water, reduces runoff, 

and minimizes the risk of erosion. To avoid loss of water 

and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. A 

rotation of grain followed by alfalfa and grass commonly is 

used. Growing annual or perennial cover crops in orchards 

and vineyards reduces water erosion. 

The main limitations for nonirrigated crops are low annual 

precipitation, moderate available water capacity, and the 

hazard of water erosion. Because precipitation is not 

sufficient for annual cropping, a cropping system that 

includes winter wheat and summer fallow is most suitable. 

Erosion can be reduced by seeding fall grain early and 

stubble mulching. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Using terraces and 

stripcropping, either singly or in combination, also reduce 

erosion. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation on the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, 

and big sagebrush. The potential native vegetation on the 

Burke soil is mainly bluebunch wheatgrass, Sandberg 

bluegrass, and Thurber needlegrass. The potential native 

vegetation on the Wiehl soil is mainly bluebunch wheatgrass 

and needleandthread. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are depth to the hardpan in the Harwood 

and Burke soils, depth to soft sandstone in the Wiehl soil, 

and steepness of slope. The hardpan and soft sandstone 

hinder excavation. Dustiness can be a 
problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are

depth to the hardpan in the Harwood and Burke soils and 

depth to soft sandstone in the Wiehl soil. The hardpan and 

sandstone limit the capacity of the absorption fields. Use of 

long absorption lines helps to compensate for these 

limitations. Absorption lines should be installed on the 

contour. Slope can promote lateral seepage and surfacing of 

effluent in downslope areas. 

This map unit is in capability subclass IVe, irrigated and 

nonirrigated. 

53-Harwood-Burke-Wiehl silt loams, 15 to 30 percent 

slopes. This map unit is on uplands. The native vegetation is 

grasses, forbs, and shrubs. Elevation is 11,000 to 1,300 feet. 

The average annual precipitation is 6 to 10 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 170 days. 

This unit is about 30 percent Harwood silt loam, about 30 

percent Burke silt loam, and about 20 percent Wiehl silt 

loam. The components of this unit are so intricately 

intermingled that it was not practical to map them separately 

at the scale used. 

Included in this unit are areas of Ritzville, Selah, Starbuck, 

and Scoon soils, salt- and alkali-affected soils, Rock outcrop, 

and soils that have slopes of less than 15 percent or more 

than 30 percent. Also included are areas of soils that have 

hardpan fragments scattered through the profile and areas 

of soils that have laminated sediment at a depth of 20 to 40 

inches. These included areas make up about 20 percent of 

the total acreage. 

The Harwood soil is well drained. It is moderately deep 

over a hardpan. It formed in loess and old alluvium. Typically, 

the surface layer is grayish brown silt loam about 8 inches 

thick. The subsoil is brown silt loam about 18 inches thick. 

The substratum is brown gravelly silt loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas the 

surface layer is very fine sandy loam. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is rapid, and the hazard of water erosion is high. 

The Burke soil is well drained and is moderately deep over 

a hardpan. It formed in loess. Typically, the surface layer is 

pale brown silt loam about 7 inches thick. The substratum is 

pale brown silt loam about 18 inches thick. A hardpan is at 

a depth of about 25 inches. Depth to the hardpan ranges 

from 20 to 40 inches. In some areas the surface layer is very 

fine sandy loam. 

 Permeability of the Burke soil is moderate above the 

hardpan and very slow through it. Available water 

capacity is moderate. Effective rooting depth is 20 to 40

inches. Runoff is rapid, and the hazard of water erosion 

is high. 

The Wiehl soil is moderately deep and well drained. It 

formed in loess. Typically, the surface layer is grayish brown 

silt loam about 3 inches thick. The subsoil is brown and 

pale brown silt loam about 18 inches thick. The substratum 

is pale brown gravelly silt loam about 6 inches thick. Weakly 

cemented, soft sandstone is at a depth of about 27 inches. 

Depth to sandstone ranges from 20 to 40 inches. In some 

areas the surface layer is very fine sandy loam. 

Permeability of the Wiehl soil is moderate above the 

sandstone and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 

This unit is used for irrigated hay, pasture, and orchard 

crops, for nonirrigated crops, as rangeland and homesites, 

and for wildlife habitat. The main irrigated crops are grasses, 

legumes, grapes, and tree fruit. A cover crop is grown in 

orchards. 

The main limitations for irrigated crops are steepness of 

slope, the hazard of water erosion, depth to the hardpan in 

the Harwood and Burke soils, and depth to sandstone in the 

Wiehl soil. Sprinkler and drip irrigation systems are suited to 

the soils in this unit. Use of these systems permits the even, 

controlled application of water, reduces runoff, and minimizes 

the risk of erosion. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity and 

the crop needs. Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces water 

erosion. Perennial cover crops are needed in orchards and 

vineyards to reduce water erosion. 

The main limitations for nonirrigated crops are low annual 

precipitation, the hazard of water erosion, and moderate 

available water capacity. Because precipitation is not 

sufficient for annual cropping, a cropping system that 

includes winter wheat and summer fallow is most suitable. 

Seeding fall grain early and stubble mulching reduce the risk 

of erosion. Seeding on the contour or across the slope slows 

runoff and reduces erosion when the snow melts rapidly 

while the soil is still frozen. Divided-slope farming and 

stripcropping also reduce erosion. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial grass. 

The potential native vegetation of the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, 

and big sagebrush. The potential native vegetation of the 

Burke soil is mainly bluebunch wheatgrass, Sandberg 

bluegrass, and Thurber needlegrass. The potential native 

vegetation of the Wiehl soil is mainly bluebunch 
wheatgrass and needleandthread. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as chaining, 

railing, beating, plowing, chemical treatment, and 

prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition. The unit should be 

seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are steepness of slope and depth to the 

hardpan in the Harwood and Burke soils and depth to 

sandstone in the Wiehl soil. The hardpan and sandstone 

hinder excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

steepness of slope, depth to the hardpan in the Harwood 

and Burke soils, and depth to sandstone in the Wiehl soil. 

The hardpan and sandstone limit the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for these limitations. Slope can promote lateral 

seepage and surfacing of effluent in downslope areas. 

This map unit is capability subclass IVe, irrigated 

and nonirrigated. 

54-Harwood-Burke-Wiehl silt loams, 30 to 60 percent 

slopes. This map unit is on uplands. The native vegetation 

is grasses, forbs, and shrubs. Elevation is 1,000 to 

1,200 feet. The average annual precipitation is 6 to 10 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 170 

days. 

This unit is about 30 percent Harwood silt loam, 30 to 60 

percent slopes; about 30 percent Burke silt loam, 30 to 40 

percent slopes; and about 20 percent Wiehl silt loam, 30 to 

60 percent slopes. The components of this unit are so 

intricately intermingled that it was not practical to map them 

separately at the scale used. 

Included in this unit are about 10 percent Kiona soils, 5 

percent Ritzville soils, and 5 percent Scoon soils and soils 

that have slopes of less than 30 percent. Also included are 

areas of soils that have hardpan fragments scattered 

throughout the profile and on the surface and areas of soils 

that have laminated sediment at a depth of 20 to 40 inches. 

These inclusions make up about 25 percent of the total 

acreage. 

The Harwood soil is well drained. It is moderately deep over 

a hardpan. It formed in loess and old alluvium. Typically, the 

surface layer is grayish brown silt loam about 8 inches thick. 

The subsoil is brown silt loam about 18 inches thick. The 

substratum is brown gravelly 

silt loam about 4 inches thick. A hardpan is at a depth of 

about 30 inches. Depth to the hardpan ranges from 20 to 40 

inches. In some areas the surface layer is very fine sandy 

loam or is very stony. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is very rapid, and the hazard of water erosion is very high. 

The Burke soil is well drained and is moderately deep over 

a hardpan. It formed in loess. Typically, the surface layer is 

pale brown silt loam about 7 inches thick. The substratum is 

pale brown silt loam about 18 inches thick. A hardpan is at a 

depth of about 25 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the surface layer is very fine 

sandy loam or is very stony. 

 Permeability of the Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is very rapid, and the hazard of water erosion is very high. 

The Wiehl soil is moderately deep and well drained. It 

formed in loess. Typically, the surface layer is grayish brown 

silt loam about 3 inches thick. The subsoil is brown and pale 

brown silt loam about 18 inches thick. The substratum is 

pale brown gravelly silt loam about 6 inches thick. Weakly 

cemented sandstone is at a depth of about 27 inches. Depth 

to sandstone ranges from 20 to 40 inches. In some areas the 

surface layer is very fine sandy loam or is very stony. 

Permeability of the Wiehl soil is moderate above the 

sandstone and very slow through it. Available water capacity 

is moderate. Effective rooting depth is 20 to 40 inches. 

Runoff is very rapid, and the hazard of water erosion is very 

high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, and big 

sagebrush. The potential native vegetation on the Burke soil 

is mainly bluebunch wheatgrass, Sandberg bluegrass, 

and Thurber needlegrass. The potential native vegetation on 

the Wiehl soil is mainly bluebunch wheatgrass and 

needleandthread. The production of forage is limited by the 

steepness of slope, which restricts access by livestock and 

promotes overgrazing of the less sloping areas. Proper 

location of salt licks, stock water tanks, and fences promotes 

more uniform distribution of grazing. 

If the range is overgrazed, the proportion of preferred 

forage plants such as bluebunch wheatgrass decreases and 

the proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. Areas that are heavily 

infested with undesirable vegetation can be improved by 

such methods as chemical treatment and prescribed 

burning. Seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded 

in fall using a drill. Use of equipment is limited in 
the more steeply sloping areas. Adapted grasses and 

legumes should be seeded. 

This map unit is in capability subclass VIle, 

nonirrigated. 

55-Harwood-Burke-Wiehl very stony silt loams, 15 to 

30 percent slopes. This map unit is on uplands. The native 

vegetation is grasses, forbs, and shrubs. Elevation is 

1,000 to 1,300 feet. The average annual precipitation is 6 to 

10 inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 170 

days. 

This unit is about 30 percent Harwood very stony silt 

loam, about 30 percent Burke very stony silt loam, and 

about 20 percent Wiehl very stony silt loam. The 

components of this unit are so intricately intermingled that 

it was not practical to map them separately at the scale 

used. 

Included in this unit areas of Ritzville and Kiona soils and 

areas of soils that have slopes of less than 15 percent. 

Also included are areas of soils that have hardpan 

fragments scattered throughout the profile and soils that 

have laminated sediment at a depth of 20 to 40 inches. 

These included areas make up about 20 percent of the total 

acreage. 

The Harwood soil is well drained and is moderately deep 

over a hardpan. It formed in loess and old alluvium. 

Typically, the surface layer is grayish brown very stony 

silt loam about 8 inches thick. The subsoil is brown silt loam 

about 18 inches thick. The substratum is brown gravelly silt 

loam about 4 inches thick. A hardpan is at a depth of 30 

inches. Depth to the hardpan ranges from 20 to 40 inches. In 

some areas, the surface layer is fine sandy loam and the soil 

does not have stones on the surface. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

The Burke soil is well drained and is moderately deep 

over a hardpan. It formed in loess. Typically, the surface 

layer is pale brown very stony silt loam about 7 inches thick. 

The substratum is pale brown silt loam about 18 inches 

thick. A hardpan is at a depth of about 25 inches. Depth to 

the hardpan ranges from 20 to 40 inches. In some areas, the 

surface layer is fine sandy loam and the soil does not have 

stones on the surface. 

Permeability of the Burke soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

The Wiehl soil is moderately deep and well drained. It 

formed in loess. Typically, the surface layer is grayish 

brown very stony silt loam about 3 inches thick. The subsoil 

is brown and pale brown silt loam about 18 

inches thick. The substratum is pale brown gravelly silt loam 

about 6 inches thick. Weakly cemented sandstone is at a 

depth of about 27 inches. Depth to sandstone ranges from 

20 to 40 inches. In some areas, the surface layer is fine 

sandy loam and the soil does not have stones on the 

surface. 

Permeability of the Wiehl soil is moderate above the 

sandstone and very slow through it. Available water 

capacity is moderate. Effective rooting depth is 20 to 40 

inches. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, and 

big sagebrush. The potential native vegetation on the Burke 

soil is mainly bluebunch wheatgrass, Sandberg 

bluegrass, and Thurber needlegrass. The potential native 

vegetation on the Wiehl soil is mainly bluebunch wheatgrass 

and needleandthread. The production of forage is limited by 

the large stones on the surface. If the range is overgrazed, 

the proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chemical treatment 

and prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition, but it is difficult 

because of the large stones on the surface. The unit should 

be seeded in fall using a drill or by broadcasting. Adapted 

grasses and legumes should be seeded. 

This map unit is in capability subclass VIs, 

nonirrigated. 

56-Harwood-Gorst complex, 0 to 25 percent slopes. 

This map unit is on dissected terraces. The native vegetation 

is grasses, forbs, and shrubs. Elevation is 1,200 to 2,000 feet. 

The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 51 degrees F, and 

the average frost-free season is 135 to 150 days. 

This unit is about 60 percent Harwood loam and about 30 

percent Gorst cobbly loam. The Harwood soil is on mounds, 

and the Gorst soil is in areas between the mounds. The 

components of this unit are so intricately intermingled that it 

was not practical to map them separately at the scale used. 

Included in this unit are areas of Cowiche, Selah, and 

Rock Creek soils. Also included are areas of Gorst soils that 

have a very cobbly or very gravelly surface layer and areas 

of Harwood and Gorst soils that have slopes of more than 

25 percent. These included areas make up about 10 

percent of the total acreage. 

The Harwood soil is well drained. It is moderately deep 

over a hardpan. It formed in loess and old alluvium. Typically 

the surface layer is grayish brown loam about 8 
inches thick. The subsoil is brown loam about 18 inches 

thick. The substratum is brown gravelly loam about 4 inches 

thick. A hardpan is at a depth of about 30 inches. Depth to 

the hardpan ranges from 20 to 40 inches. 

Permeability of the Harwood soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderate. Effective rooting depth is 20 to 40 inches. Runoff 

is medium, and the hazard of water erosion is moderate. 

The Gorst soil is well drained. It is shallow over a 

hardpan. It formed in loess and old alluvium. Typically, the 

surface layer is brown cobbly loam about 7 inches thick. 

The subsoil is pale brown and brown loam about 8 inches 

thick. A hardpan is at a depth of about 15 inches. Depth to 

the hardpan ranges from 12 to 20 inches. 

Permeability of the Gorst soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low, Effective rooting depth is 12 to 20 inches. Runoff is 

rapid, and the hazard of water erosion is high. 

This unit is used as rangeland and for irrigated field and 

orchard crops, wildlife habitat, and homesites. The main 

irrigated crops are tree fruit and grasses and legumes 

grown for hay, pasture, and seed. A perennial cover crop is 

grown in orchards. 

The potential native vegetation on the Harwood soil is 

mainly bluebunch wheatgrass, Sandberg bluegrass, and big 

sagebrush. The potential native vegetation on the Gorst soil 

is mainly bluebunch wheatgrass and Thurber needlegrass. 

The production of forage is limited by the low annual 

precipitation, depth to the hardpan, very low available water 

capacity, and large stones on the Gorst soil. If the range is 

overgrazed, the proportion of preferred forage plants such as 

bluebunch wheatgrass decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, chemical treatment, and prescribed burning. Seeding 

is a suitable practice if the range vegetation is in poor 

condition. The unit should be seeded in fall using a drill. 

Undesirable vegetation on the Gorst soil can be controlled by 

chemical methods. Use of equipment is difficult because of 

the presence of cobbles. Removal of the cobbles may be 

necessary before using equipment. Adapted grasses and 

legumes should be seeded. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, the hazard of water erosion, 

and large stones on the surface of the Gorst soil. This unit 

can be leveled by spreading the mounds of the Harwood soil 

over the Gorst soil so that the entire area is underlain by a 

hardpan at a depth of about 16 to 25 inches. Exposing the 

hardpan when leveling fields should be avoided. 

Shallow soil depth makes water management extremely 

important. Sprinkler and drip irrigation systems 

are suited to the soils in this unit. Use of these systems 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. To avoid loss of 

water and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity, the water intake rate, and the crop 

needs. Growing perennial cover crops in orchards reduces 

erosion. 

This unit is poorly suited to homesite development. The 

main limitations are depth to the hardpan and steepness of 

slope in areas where the slope is more than 15 percent. The 

hardpan hinders excavation. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

depth to the hardpan, which limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Absorption lines should be 

installed on the contour. Slope can cause lateral seepage and 

surfacing of effluent in downslope areas. 

This map unit is in capability subclass Vle, irrigated 

and nonirrigated. 

57-Hezel loamy fine sand, 0 to 2 percent slopes. 

This very deep, somewhat excessively drained soil is on 

terraces. It formed in lacustrine sediment overlain by a 

mantle of eolian sand. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 650 to 800 feet. The 

average annual precipitation is 6 to 8 inches, the average 

annual air temperature is about 53 degrees F, and the 

average frost-free season is 150 to 180 days. 

Typically, the surface layer is grayish brown loamy fine 

sand about 6 inches thick. The upper part of the underlying 

material is grayish brown and light brownish gray loamy fine 

sand about 16 inches thick, and the lower part to a depth of 

60 inches or more is stratified, light brownish gray very fine 

sandy loam and silt loam. 

Included in this unit are areas of Warden and Quincy 

soils. Also included, in depressional areas, are soils that 

have a high water table and a high salt content if the 

surrounding areas are irrigated. 

Permeability of this Hezel soil is rapid in the loamy fine 

sand part and moderately slow in the underlying stratified 

material. Available water capacity is high. Effective rooting 

depth is 60 inches or more. Runoff is very slow, and the 

hazard of water erosion is slight. The hazard of soil blowing is 

high. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are grain, 

potatoes, and corn. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of soil 

blowing. The type of irrigation system used depends on the 

kind of crop grown. A sprinkler system is best suited to the 

soil in this unit. Use of sprinkler irrigation permits the even, 

controlled application of irrigation 
water, reduces runoff, and minimizes the risk of water 

erosion. Because of rapid permeability, irrigation furrows 

need to be compacted and shaped so that irrigation water 

can reach the entire length of the run. This reduces the 

water intake rate. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. Because this soil is 

droughty, frequent, light applications of irrigation water are 

needed. 

The hazard of sail blowing makes tillage and residue 

management extremely important. This unit should be 

protected with cover crops or crop residue through the 

period of soil blowing in spring until the crop is well 

established. Sufficient crop residue should be left on the 

surface. Fall grain, hay, or pasture should be seeded late in 

August or early in September to provide sufficient cover. 

Use of straw, manure, or other waste material as a mulch 

reduces soil blowing, helps to maintain or improve the 

organic matter content, and conserves moisture. Seedbeds 

should be prepared when irrigation water is available to keep 

the soil surface moist. Vegetative barriers and shelterbelts 

are suitable for controlling soil blowing. Small grain can be 

used as a nurse crop when establishing grasses and 

legumes. 

This unit has few limitations for homesite development. 

Building sites should be disturbed as little as possible. The 

main limitation for septic tank absorption fields is the 

moderately slow permeability, which affects the rate of 

absorption of the effluent. Use of sandy backfill for the 

trench and long absorption lines helps to compensate for this 

limitation. 

This map unit is in capability subclass IVe, irrigated. 

58-Hezel loamy fine sand, 2 to 15 percent slopes. 

This very deep, somewhat excessively drained soil is on 

terraces. It formed in lacustrine sediment overlain by a 

mantle of eolian sand. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 650 to 800 feet. The 

average annual precipitation is 6 to 8 inches, the average 

annual air temperature is about 53 degrees F, and the 

average frost-free season is about 150 to 180 days. 

Typically, the surface layer is grayish brown loamy fine sand 

about 6 inches thick. The upper part of the underlying 

material is grayish brown and light brownish gray loamy 

fine sand about 16 inches thick, and the lower part to a depth 

of 60 inches or more is stratified, light brownish gray loamy 

very fine sandy loam and silt loam. 

Included in this unit are areas of Warden and Quincy soils 

and soils, in depressional areas, that have a high water 

table and a high concentration of salt if the surrounding 

areas are irrigated. Also included are areas of Hezel 

soils that have slopes of more than 15 percent. 

Permeability of this Hezel soil is rapid in the loamy fine 

sand part and moderately slow in the underlying stratified 

material. Available water capacity is high. Effective rooting 

depth is 60 inches or more. Runoff is slow, and the hazard of 

water erosion is slight. The hazard of soil blowing is high. 

This unit is used for irrigated crops and as rangeland, 

wildlife habitat, and homesites. The main irrigated crops are 

grain and potatoes. Grasses and legumes are grown for hay, 

pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of wind erosion. Sprinkler irrigation 

systems are suited to the soil in this unit. Use of these 

systems permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of water erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity the water intake 

rate, and the crop needs. Because of the droughtiness of the 

surface layer, frequent light applications of irrigation water 

are needed. 

The high hazard of wind erosion makes proper tillage and 

residue management extremely important. This unit should be 

protected with a cover crop when it is susceptible to wind 

erosion in winter and with crop residue until crops are well 

established in spring. Crop rows should be at right angles to 

the prevailing wind wherever feasible. Fall grain, hay, or 

pasture should be seeded late in August or early in 

September to provide sufficient winter cover. Use of straw, 

manure, or other waste material as a mulch reduces soil 

blowing, helps to maintain or improve the organic matter 

content, and conserves moisture. Seedbeds should be 

prepared when irrigation water is available to keep the soil 

surface moist. Vegetative barriers and shelterbelts also 

reduce soil blowing. 

The potential native vegetation on this unit is mainly 

needleandthread, Sandberg bluegrass, bluebunch 

wheatgrass, and big sagebrush. The production of forage is 

limited by the hazard of soil blowing. If the range is 

overgrazed, the proportion of preferred forage plants such as 

needleandthread and bluebunch wheatgrass decreases and 

the proportion of less preferred forage plants such as 

balsamroot and big sagebrush increases. 

Brush control is mainly limited to chemical application 

because of the high hazard of soil blowing. Seeding is a 

suitable practice if the range vegetation is in poor 

condition. The unit should be seeded with a rangeland drill 

in fall when the moisture content of the soil is optimal. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is steepness of slope. Building sites should 

be disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

moderately slow permeability, which affects the rate of 

absorption of the effluent. Use of sandy backfill for the 
trench and long absorption lines helps to compensate for 

this limitation. Absorption lines should be installed on the 

contour. 

This map unit is in capability subclasses IVe, 

irrigated, and Vle, nonirrigated. 

59-Jumpe stony loam, 5 to 25 percent slopes. This 

very deep, well drained soil is on long, broad mountain 

ridges. It formed in residuum and colluvium derived from 

basalt and a small amount of loess and volcanic ash. The 

native vegetation is mainly conifers, grasses, forbs, and 

shrubs. Elevation is 3,800 to 5,600 feet. The average annual 

precipitation is 25 to 40 inches, the average annual air 

temperature is about 43 degrees F, and the average length 

of the growing season, at 28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material, about 2 inches thick. The 

surface layer is brown stony loam about 3 inches thick. The 

subsoil is brown and dark yellowish brown extremely cobbly 

loam about 38 inches thick. The substratum to a depth of 60 

inches or more is yellowish brown extremely cobbly loam. In 

some areas at an elevation of more than 5,000 feet, a layer 

of volcanic ash 4 to 12 inches thick is on the surface; in 

some areas the subsoil is clay loam or sandy loam; and in 

some areas basalt is at a depth of 30 to 40 inches. 

Included in this unit are areas of Bocker soils and 

areas of Jumpe soils that have slopes of 25 to 45 

percent. 

Permeability of this Jumpe soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

The unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. Among the trees of limited extent are 

grand fir, western larch, and occasional dense stands of 

lodgepole pine. On the basis of a 100-year site curve, the 

mean site index is 80 for Douglas-fir, 67 for ponderosa pine, 

and 73 for grand fir. On the basis of a 50-year site curve, the 

mean site index is 59 for western larch. Yield tables for 

normal, even-aged, unmanaged stands indicate that the 

mean annual increment at culmination (CMAI) for trees 0.6 

inch in diameter and larger is 69 cubic feet per acre for 

Douglas-fir at age 40 and 52 cubic feet per acre for 

ponderosa pine at age 50. The mean annual increment for 

trees 6.6 inches in diameter and larger at 80 years of age is 

55 cubic feet per acre for Douglas-fir and 40 cubic feet per 

acre for ponderosa pine. However, the typical basal area of 

stands on this unit is about 70 percent that of normal stands, 

and the total yield is correspondingly lower. 

The main limitation for the harvesting of timber is a short 

period of seasonal soil wetness. Unsurfaced roads and skid 

trails are slippery when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads require suitable surfacing for year-round use. Rock 

for road construction is not readily available on this unit. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by Douglas-fir and ponderosa 

pine occurs periodically. Reforestation can be accomplished 

by planting Douglas-fir and ponderosa pine seedlings. The 

droughtiness of the surface layer during the dry summer 

months increases seedling mortality, especially on southand southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, pinemat manzanita, and ceanothus. The crown 

density in the areas where the woodland site index was 

measured is 25 percent. This unit is well suited to grazing 

and browsing. Seeding to adapted grazable vegetation 

following logging or burning late in summer or in fall 

generally is most successful. 

This map unit is in capability subclass Vls, 

nonirrigated. 

60-Jumpe stony loam, 25 to 45 percent slopes. This 

very deep, well drained soil is on mountainsides. It formed in 

residuum and colluvium derived from basalt and a small 

amount of loess and volcanic ash. Areas generally are on 

south-facing side slopes. The native vegetation is mainly 

conifers, grasses, forbs, and shrubs. Elevation is 3,600 to 

5,800 feet. The average annual precipitation is 25 to 40 

inches, the average annual air temperature is about 43 

degrees F, and the average length of the growing season, at 

28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

surface layer is brown stony loam about 3 inches thick. The 

subsoil is brown and dark yellowish brown extremely cobbly 

loam about 38 inches thick. The substratum to a depth of 60 

inches or more is yellowish brown extremely cobbly loam. In 

some areas at an elevation of more than 5,000 feet, the soil 

has a mantle of volcanic ash 4 to 12 inches thick. In some 

areas the subsoil is clay loam or sandy loam. 

Included in this unit are about 10 percent Sapkin soils, 5 

percent Bocker soils, areas of Rock outcrop and Rubble 

land, areas of Jumpe soils that have slopes of 45 to 70 

percent, and small concave areas of soils that have slopes of

5 to 25 percent. 

Permeability of this Jumpe soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. Among the trees of limited extent 
are grand fir, scattered western larch, and lodgepole pine. 

On the basis of a 100-year site curve, the mean site index is 

86 for Douglas-fir, 64 for ponderosa pine, and 73 for grand 

fir. Yield tables for normal, even-aged, unmanaged stands 

indicate that the mean annual increment at culmination 

(CMAI) for trees 0.6 inch in diameter and larger is 79 cubic 

feet per acre for Douglas-fir at age 40 and 50 cubic feet per 

acre for ponderosa pine at age 55. The mean annual 

increment for trees 6.6 inches in diameter and larger at 80 

years of age is 65 cubic feet per acre for Douglas-fir and 40 

cubic feet per acre for ponderosa pine. However, the typical 

basal area of stands on this unit is about 70 percent that of 

normal stands, and the total yield is correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. A cable warding system may be 

safer, and it disturbs the soil less. Unsurfaced roads and 

skid trails are slippery when wet, and they may be 

impassable during spring runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round 

use. Rock for road construction is not readily available on this 

unit. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by Douglas-fir and ponderosa 

pine occurs periodically. Reforestation can be accomplished 

by planting Douglas-fir and ponderosa pine seedlings. The 

droughtiness of the surface layer during the dry summer 

months increases seedling mortality, especially on 

south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, and ceanothus. The crown density in the areas 

where the woodland site index was measured is 25 percent 

This unit is well suited to grazing and browsing. It has few 

limitations for the production of forage. Seeding to adapted 

grazable vegetation following logging or burning late in 

summer or in fall generally is most successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

61-Jumpe stony loam, 45 to 65 percent slopes. This 

very deep, well drained soil is on mountainsides and in 

canyons. It formed in residuum and colluvium derived 

from basalt and small amounts of loess and volcanic ash. 

Areas generally are on south-facing side slopes. The 

native vegetation is mainly conifers, grasses, forbs, and 

shrubs. Elevation is 3,600 to 5,800 feet. The average annual 

precipitation is 25 to 40 inches, the average annual air 

temperature is about 43 degrees F, and the average 

length of the growing season, at 28 degrees F, is 145 to 170 

days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

surface layer is brown stony loam about 3 inches thick. The 

subsoil is brown and dark yellowish brown extremely cobbly 

loam about 38 inches thick. The substratum to a depth of 60 

inches or more is yellowish brown extremely cobbly loam. In 

some areas at an elevation of more than 5,000 feet, the soil 

has a mantle of volcanic ash 4 to 12 inches thick. In some 

areas the subsoil is clay loam or sandy loam. 

Included in this unit are about 10 percent Sapkin soils 

and about 15 percent areas of Rubble land, Rock outcrop, 

and Jumpe soils that have slopes of less than 45 percent. 

Permeability of this Jumpe soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used as grazable woodland and for wildlife 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. Among the trees of limited extent are 

grand fir and western larch. On the basis of a 100-year 

curve, the mean site index is 86 for Douglas-fir, 64 for 

ponderosa pine, and 73 for grand fir. Yield tables for normal, 

even-aged, unmanaged stands indicate that the mean annual 

increment at culmination (CMAI) for trees 0.6 inch in diameter 

and larger is 79 cubic feet per acre for Douglas-fir at age 40 

and 50 cubic feet per acre for ponderosa pine at age 55. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 65 cubic feet per acre for 

Douglas-fir and 50 cubic feet per acre for ponderosa pine. 

However, the typical basal area of stands on this unit is 

about 55 percent that of normal stands, and the total yield is 

correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which restricts the use of wheeled and 

tracked equipment in skidding operations. Cable yarding 

systems generally are safer and disturb the soil less. Areas 

of Rock outcrop and Rubble land hinder harvesting. 

Unsurfaced roads and skid trails are slippery when wet, and 

they may be impassable during spring runoff or in rainy 

periods. Logging roads require suitable surfacing for yearround use. Rock for road construction is readily available in 

areas of Rubble land and Rock outcrop. Steep yarding 

paths, skid trails, and firebreaks are subject to rilling and 

gullying unless adequate water bars are provided or they 

are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by Douglas-fir and ponderosa 

pine occurs periodically. Reforestation can be accomplished 

by planting Douglas-fir and ponderosa pine seedlings. The 

droughtiness of the surface layer during the dry summer 

months increases seedling mortality, especially on southand southwest-facing slopes. 
The common forest understory plants are elk sedge, 

pinegrass, and ceanothus. The crown density in the areas 

where the woodland site index was measured is 25 percent. 

This unit is suited to browsing. Seeding to adapted 

grazable vegetation following logging or burning late in 

summer or in fall generally is most successful. Because of 

the steepness of slope, broadcast seeding should be used. 

This map unit is in capability subclass Vlls, 

non irrigated. 

62-Jumpe stony loam, 25 to 45 percent north 

slopes. This very deep, well drained soil is on 

mountainsides. It formed in residuum and colluvium 

derived from basalt and a small amount of loess and 

volcanic ash. The native vegetation is mainly conifers, 

grasses, forbs, and shrubs. Elevation is 3,200 to 5,600 feet. 

The average annual precipitation is 25 to 40 inches, the 

average annual air temperature is about 42 degrees F, and 

the average length of the growing season, at 28 degrees F, 

is 135 to 160 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick and a 

layer of volcanic ash about 1/2 inch thick. The surface layer, 

where mixed to a depth of about 6 inches, is brown stony 

loam. The subsoil is dark brown and dark yellowish brown 

very cobbly loam about 31 inches thick. The substratum to a 

depth of 60 inches or more is dark yellowish brown very 

cobbly loam. In some areas the soil has a mantle of volcanic 

ash about 12 inches thick. 

Included in this unit are areas of Rock outcrop and 

Rubble land and areas of Jumpe soils that have slopes of 

less than 25 percent or more than 45 percent. 

Permeability of this Jumpe soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir, grand fir, and western larch are the main 

woodland species on this unit. Among the trees of limited 

extent are lodgepole pine, Engelmann spruce, western 

white pine, and some ponderosa pine on the more nearly 

west- and east-facing side slopes. On the basis of a 100-

year site curve, the mean site index is 75 for Douglas-fir, 73 

for grand fir, and 65 for ponderosa pine. On the basis of a 

50-year site curve, the mean site index is 42 for western 

larch. Yield tables for normal, even-aged, unmanaged 

stands indicate that the mean annual increment at 

culmination (CMAI) for Douglas-fir trees 0.6 inch in diameter 

and larger at 45 years of age is 62 cubic feet per acre. The 

mean annual increment for Douglas-fir trees 6.6 inches in 

diameter and larger at 80 years of age is 55 cubic feet per 

acre. However, the typical basal area of stands on this unit 

is about 90 percent that of normal stands, and the total yield 

is correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. A cable yarding system may be 

safer, and it disturbs the soil less. The north-facing slopes 

of this unit retain snowpack, which delays access in spring. 

Unsurfaced roads and skid trails are slippery when wet, and 

they may be impassable during spring runoff or in rainy 

periods. Logging roads require suitable surfacing for yearround use. Rock for road construction generally is available 

in the included areas of Rubble land and Rock outcrop. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting Douglas-fir seedlings. If seed trees are present, 

natural reforestation of cutover areas by grand fir occurs 

readily and can delay establishment of planted seedlings. 

The droughtiness of the surface layer during 

the dry summer months increases seedling mortality. 

The common forest understory plants are elk sedge, 

pinegrass, spirea, and lupine. The crown density in the areas 

where the woodland site index was measured is 35 percent. 

This unit is suited to grazing and browsing. Seeding to 

adapted grazable vegetation following logging or burning late 

in summer or in fall generally is most successful. 

This map unit is in capability subclass Vlls, 

non irrigated. 

63-Jumpe stony loam, 45 to 65 percent north slopes. 

This very deep, well drained soil is on mountainsides and in 

canyons. It formed in residuum and colluvium derived from 

basalt and small amounts of loess and volcanic ash. The 

native vegetation is mainly conifers, grasses, and forbs. 

Elevation is 3,200 to 5,600 feet. The average annual 

precipitation is 25 to 40 inches, the average annual air 

temperature is about 42 degrees F, and the average length 

of the growing season, at 28 degrees F, is 135 to 160 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick and a 

layer of volcanic ash about 1 /2 inch thick. The surface layer, 

where mixed to a depth of about 6 inches, is brown stony 

loam. The subsoil is dark brown and dark yellowish brown 

very cobbly loam about 31 inches thick. The substratum to a 

depth of 60 inches or more is dark yellowish brown very 

cobbly loam. In some areas the soil has a mantle of volcanic 

ash about 12 inches thick. 

Included in this unit are areas of Rubble land and Rock 

outcrop and small concave areas of Jumpe soils that 

have slopes of less than 45 percent. 

Permeability of this Jumpe soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used as grazable woodland and for wildlife 

habitat. 
Douglas-fir and grand fir are the main woodland species 

on this unit. Among the trees of limited extent are Engelmann 

spruce, subalpine fir, and dense pockets of western larch and 

lodgepole pine. On the basis of a 100-year site curve, the 

mean site index is 75 for Douglas-fir, 73 for grand fir, and 68 

for lodgepole pine. Yield tables for normal, even-aged, 

unmanaged stands of Douglas-fir indicate that the mean 

annual increment at culmination (CMAI) for trees 0.6 inch in 

diameter and larger at 45 years of age is 62 cubic feet per 

acre. The mean annual increment for Douglas-fir trees 6.6 

inches in diameter and larger at 80 years of age is 40 cubic 

feet per acre. However, the typical basal area of stands on 

this unit is about 120 percent that of normal stands, and the 

total yield is correspondingly higher. 

The main limitation for the harvesting of timber is 

steepness of slope, which restricts the use of wheeled and 

tracked equipment in skidding operations. Cable 

yarding systems generally are safer and disturb the soil 

less. The north-facing areas of this unit retain snowpack, 

which delays access in spring. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Rock for road 

construction generally is available in included areas of 

Rubble land and Rock outcrop. Steep yarding paths, skid 

trails, and firebreaks are subject to rilling and gullying unless 

adequate water bars are provided or they are protected by 

plant cover. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting Douglas-fir seedlings. If seed trees are present, 

natural reforestation of cutover areas by grand fir and 

subalpine fir occurs readily and can delay establishment of 

planted seedlings. The droughtiness of the surface layer 

during the dry summer months increases seedling mortality. 

The common forest understory plants are lupine, 

pinegrass, and elk sedge. The crown density in the areas 

where the woodland site index was measured is 35 percent. 

This unit is poorly suited to grazing. Steepness of slope limits 

access by livestock. Seeding to adapted grazable vegetation 

following logging or burning late in summer or in fall generally 

is most successful. Because of the steepness of slope, 

broadcast seeding should be used. 

This map unit is in capability subclass VIls, 

nonirrigated. 

64-Jumpe-Rock outcrop complex, 40 to 80 percent 

slopes. This map unit is on mountainsides and in canyons. 

Areas generally are on north-facing side slopes. The 

native vegetation is mainly conifers, grasses, and forbs. 

Elevation is 2,800 to 4,400 feet. The average annual 

precipitation is 25 to 40 inches, the average annual air 

temperature is about 42 degrees F, and the average length of 

the growing season, at 28 degrees F, is 135 to 160 days. 

This unit is about 60 percent Jumpe stony loam, 40 to 65 

percent slopes, and about 20 percent Rock outcrop. The 

components of this unit are so intricately intermingled that it 

was not practical to map them separately at the scale used. 

Included in this unit are areas of Rubble land and areas of 

soils that are underlain by bedrock at a depth of 20 to 40 

inches. Also included are small concave areas of Jumpe soils 

that have slopes of less than 40 percent. These included 

areas make up about 20 percent of the total acreage. 

The Jumpe soil is very deep and well drained. It formed in 

residuum and colluvium derived from basalt and small 

amounts of loess and volcanic ash. Typically, the surface is 

covered with a mat of partially decomposed organic material 

about 2 inches thick and a layer of volcanic ash about 1/2 

inch thick. The surface layer, where mixed to a depth of 

about 6 inches, is brown stony loam. The subsoil is dark 

brown and dark yellowish brown very cobbly loam about 31 

inches thick. The substratum to a depth of 60 inches or more 

is dark yellowish brown very cobbly loam. 

Permeability of the Jumpe soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

Rock outcrop is areas of exposed bedrock. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and grand fir are the main woodland species 

on the Jumpe soil. Among the trees of limited extent are 

Engelmann spruce, subalpine fir, and dense pockets of 

western larch and lodgepole pine. On the basis of a 100-

year site curve, the mean site index is 75 for Douglas- fir, 

73 for grand fir, and 68 for lodgepole pine. Yield tables for 

normal, even-aged, unmanaged stands of Douglas-fir 

indicate that the mean annual increment at culmination 

(CMAI) for trees 0.6 inch in diameter and larger at 45 years 

of age is 62 cubic feet per acre. The mean annual 

increment for Douglas-fir trees 6.6 inches in diameter and 

larger at 80 years of age is 40 cubic feet per acre. However, 

the typical basal area of stands on the Jumpe soil is about 

120 percent that of normal stands, and the total yields are 

correspondingly higher. 

The main limitations for the harvesting of timber are the 

areas of Rock outcrop and Rubble land and steepness of 

slope. When harvesting timber, steepness of slope restricts 

the use of wheeled and tracked equipment in skidding 

operations; cable yarding systems generally are safer and 

disturb the soil less. The areas of Rock outcrop and Rubble 

land may cause breakage of timber during felling, and they 

hinder yarding. The north-facing areas of this unit retain 

snowpack, which may delay access in spring. Unsurfaced 

roads and skid trails are slippery when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads 
require suitable surfacing for year-round use. Rock for road 

construction is readily available on this unit. Steep yarding 

paths, skid trails, and firebreaks are subject to rilling and 

gullying unless adequate water bars are provided or they 

are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting Douglas-fir seedlings. If seed trees are present, 

natural reforestation of cutover areas by grand fir and 

subalpine fir occurs readily and can delay establishment of 

planted seedlings. The areas of Rock outcrop limit the even 

distribution of reforestation. The droughtiness of the surface 

layer during the dry summer months increases seedling 

mortality. 

The common forest understory plants are elk sedge, 

pinegrass, and lupine. The crown density in the areas where 

the woodland site index was measured is 30 percent. The 

Jumpe soil is poorly suited to grazing. Steepness of slope 

and the areas of Rock outcrop limit access by livestock. 

Seeding to adapted grazable vegetation following logging or 

burning late in summer or in fall generally is most successful.

This map unit is in capability subclass VIIs, 

nonirrigated. 

65-Kiona stony silt loam, 15 to 45 percent slopes. 

This very deep, well drained soil is on uplands. It formed in 

loess and colluvium derived from basalt. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 800 to 2,500 feet. The average annual 

precipitation is 7 to 12 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 140 to 200 days. 

Typically, the surface layer is brown stony silt loam about 

5 inches thick. The subsoil is pale brown very cobbly silt 

loam about 9 inches thick. The substratum to a depth of 60 

inches or more is pale brown very cobbly silt loam. 

Included in this unit are areas of Lickskillet, Starbuck, 

Ritzville, Burke, Shano, Renslow, and Bakeoven soils. 

Also included are areas of soils that are underlain by basalt 

at a depth of 30 to 40 inches, areas of Rock outcrop and 

Rubble land, and areas of Kiona soils that have slopes of 

less than 15 percent. 

Permeability of this Kiona soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Sandberg bluegrass, and Thurber 

needlegrass. The production of forage is limited by large 

stones. If the range is overgrazed, the proportion of preferred 

forage plants such as bluebunch wheatgrass decreases and 

the proportion of less preferred forage plants such as big 

sagebrush and rubber rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chemical treatment 

and prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition. Mechanical seeding is 

difficult because of stoniness. This unit should be seeded 

with a drill in fall when the moisture content of the soil is 

optimal. Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass VIs, 

nonirrigated. 

66-Kittitas silt loam. This very deep, artificially drained 

soil is on flood plains. It formed in mixed alluvium. Slope is 

0 to 2 percent. The native vegetation is mainly salt-tolerant 

grasses and shrubs. Elevation is 700 to 1,100 feet. The 

average annual precipitation is 6 to 12 inches, the average 

annual air temperature is about 51 degrees F, and the 

average frost-free season is 130 to 180 days. 

Typically, the surface layer is dark grayish brown and 

grayish brown, very strongly alkaline silt loam about 19 

inches thick. The upper part of the underlying material is 

light brownish gray, moderately alkaline silt loam about 22 

inches thick, and the lower part to a depth of 60 inches or 

more is light brownish gray, moderately alkaline very fine 

sandy loam and fine sandy loam. In some areas the surface 

layer is silty clay loam. 

Included in this unit are small areas of Toppenish and 

Umapine soils, areas of Kittitas soils that are not artificially 

drained and are salt-affected, and areas of Kittitas soils that 

have slopes of more than 2 percent. 

Permeability of this Kittitas soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

limited by a seasonal high water table that is at a depth of 18 

to 42 inches from June to November. Runoff is very slow, 

and the hazard of water erosion is slight. This soil is subject 

to rare periods of flooding. 

This unit is used for crops, for wildlife habitat, and as 

homesites. Where the unit is protected from flooding and is 

drained, leached, and irrigated, the main crops are corn, 

grain, and hops. Grasses and legumes are grown for hay, 

pasture, and seed. Deep-rooted crops are suited to areas 

where the drainage is adequate or where a drainage system 

has been installed and maintained. 

If a drainage system is not maintained, the soil in this unit 

has a seasonal high water table during the irrigation season 

and has a high content of salt. Dikes can be used to divert 

floodwater and thus reduce the risk of flooding. 

Reclamation may require the addition of such amendments 

as gypsum, sulfur, or ferric sulfate to facilitate leaching. 

Furrow, corrugation, and sprinkler irrigation systems are 

suited to the soil in this unit. The water application rate 

should be reduced to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and 

leaching of plant nutrients from overirrigation, 
applications of irrigation water should be adjusted to the 

available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to avoid compaction, to maintain or improve the 

organic matter content, to maintain tilth, and to improve the 

water infiltration rate. Using vegetated filter strips at the end 

of rows and using sediment ponds, or both, reduces the 

amount of sediment in the tailwater. A plowpan develops in 

this soil; however, it can be broken by chiseling or subsoiling 

when the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Dikes and 

channels that have outlets to bypass floodwater can be 

used to protect buildings. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. Selection of 

adapted vegetation is critical for the establishment of lawns, 

shrubs, trees, and vegetable gardens. 

The main limitations for septic tank absorption fields are 

the high water table and moderately slow permeability. 

The moderately slow permeability and the high water table 

increase the possibility of failure of septic tank absorption 

fields. 

This map unit is in capability subclass IIIw, irrigated. 

67-Lickskillet silt loam, 5 to 30 percent slopes. This 

shallow, well drained soil is on uplands. It formed in loess 

and in residuum and colluvium derived from basalt. Most 

slopes are about 10 percent. The native vegetation is 

mainly grasses, forbs, and shrubs (fig. 2). Elevation is 

1,500 to 3,200 feet. The average annual precipitation is 10 

to 12 inches, the average annual air temperature is about 48 

degrees F, and the average frost-free season is 120 to 150 

days. 

Typically, the surface layer is grayish brown silt loam 

about 3 inches thick. The upper part of the subsoil is 

Figure 2.-Typical area of Lickskillet silt loam, 5 to 30 percent slopes, in the foreground. 
brown very gravelly silt loam about 5 inches thick, and the 

lower part is yellowish brown very gravelly loam and very 

cobbly loam about 11 inches thick. Fractured basalt is at a 

depth of about 19 inches. Depth to basalt ranges from 12 to 

20 inches. In some areas the surface layer is stony. 

Included in this unit are areas of Rock Creek, Kiona, 

Starbuck, and Bakeoven soils. 

Permeability of this Lickskillet soil is moderate. Available 

water capacity is low. Effective rooting depth is 12 to 20 

inches. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used as rangeland, for wildlife habitat, and as 

homesites. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and Sandberg bluegrass. The 

production of forage is limited by the low available water 

capacity. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred species such 

as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

beating, chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. This unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are the shallow depth to rock and 

steepness of slope where the slope is more than 15 percent. 

Bedrock hinders excavation. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

depth to rock and steepness of slope. The bedrock limits 

the capacity of the absorption fields. Effluent from 

absorption fields can surface in downslope areas and thus 

create a hazard to health. Absorption lines need to be 

installed on the contour in the more nearly level areas of 

the unit. 

This map unit is in capability subclass Vle, 

nonirrigated. 

68-Lickskillet very stony silt loam, 5 to 45 percent 

slopes. This shallow, well drained soil is on uplands. It 

formed in loess and residuum and colluvium derived from 

basalt. Most slopes are about 25 percent. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,500 to 3,200 feet. The average annual 

precipitation is 10 to 12 inches, the average annual air 

temperature is about 48 degrees F, and the average frostfree season is 120 to 150 days. 

Typically, the surface layer is grayish brown very stony silt 

loam about 3 inches thick. The upper part of the subsoil is 

brown very gravelly silt loam about 5 inches 

thick, and the lower part is yellowish brown very gravelly 

loam and very cobbly loam about 11 inches thick. Fractured 

basalt is at a depth of about 19 inches. Depth to basalt 

ranges from 12 to 20 inches. In some areas the surface layer 

does not have stones. 

Included in this unit are areas of Rock Creek, Kiona, 

Starbuck, and Bakeoven soils and areas of Rock outcrop. 

Permeability of this Lickskillet soil is moderate. Available 

water capacity is low. Effective rooting depth is 12 to 20 

inches. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used as rangeland, for wildlife habitat, and as 

homesites. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and Sandberg bluegrass. The 

production of forage is limited by the low available water 

capacity and large stones on the surface. If the range is 

overgrazed, the proportion of preferred forage plants such as 

bluebunch wheatgrass decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

chemical treatment, and prescribed burning. Seeding is 

a suitable practice if the range vegetation is in poor 

condition, but it is difficult because of stoniness. This unit 

should be seeded in fall when the moisture content of the 

soil is optimal, and a rangeland drill should be used. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are depth to rock and steepness of slope in 

areas where the slope is more than 15 percent. Bedrock 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Removal of stones 

might be necessary before seeding lawns. 

The main limitations for septic tank absorption fields are 

depth to rock and steepness of slope in areas where the 

slope is more than 15 percent. Bedrock limits the capacity of 

the absorption fields. Effluent can surface in downslope 

areas and thus create a hazard to health. Absorption lines 

need to be installed on the contour in the more nearly level 

areas of the unit. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

69-Logy silt loam, 0 to 2 percent slopes. This very 

deep, well drained soil is on flood plains. It formed in 

alluvium. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 700 to 1,200 feet. The average annual 

precipitation is 7 to 10 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 
Typically, the surface layer is dark grayish brown silt loam 

about 12 inches thick. The subsoil is brown extremely 

gravelly loam about 21 inches thick. The upper part of the 

substratum is brown extremely cobbly coarse sand about 12 

inches thick, and the lower part to a depth of 60 inches or 

more is grayish brown extremely gravelly coarse sand. In 

some areas the surface layer is gravelly, cobbly, or stony. 

Included in this unit are areas of Yakima and Weirman 

soils. 

Permeability of this Logy soil is moderate to the 

substratum and very rapid through it. Available water 

capacity is low. Effective rooting depth is 60 inches or 

more. Runoff is very slow, and the hazard of water 

erosion is slight. This soil is subject to occasional periods 

of flooding from January to April. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. Grasses and legumes are grown for hay, 

pasture, and seed. The main irrigated crop is grain. 

The main limitation for irrigated crops is the low available 

water capacity. Corrugation and sprinkler irrigation 

systems are suited to the soil in this unit. If surface irrigation 

systems are used, the risk of erosion can be minimized by 

keeping runs short. Water application rates should be 

reduced to help control runoff, erosion, and the production of 

sediment. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should also be adjusted to the available water capacity and 

the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to avoid compaction, to maintain or improve the 

organic matter content, to maintain tilth, and to improve the 

water infiltration rate. Using vegetated filter strips at the end 

of rows reduces the volume of sediment in the tailwater. 

Exposing the extremely gravelly coarse sand substratum 

when leveling fields should be avoided. Shallow cuts are 

feasible in some areas. Dikes are effective in diverting 

floodwater. 

This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Dikes and channels 

that have outlets to bypass floodwater can be used to 

protect buildings from flooding. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

hazard of flooding. Flooding can be controlled only by use of 

major flood control structures. If the density of housing is 

moderate to high, community sewage systems are needed to 

prevent contamination of water supplies as a result of 

seepage from onsite sewage disposal systems. Cutbanks 

are not stable and are subject to caving in. 

This map unit is in capability subclass lVw, irrigated. 

70-Logy cobbly silt loam, 0 to 5 percent slopes. 

This very deep, well drained soil is on flood plains. It formed 

in alluvium. The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 700 to 1,200 feet. The average 

annual precipitation is 7 to 10 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is dark grayish brown cobbly 

silt loam about 12 inches thick. The subsoil is brown 

extremely gravelly loam about 21 inches thick. The upper 

part of the substratum is brown extremely cobbly coarse 

sand about 12 inches thick, and the lower part to a depth of 

60 inches or more is grayish brown extremely gravelly 

coarse sand. In some areas the surface layer does not have 

cobbles. 

Included in this unit are areas of Logy soils that have 

slopes of more than 5 percent. 

Permeability of this Logy soil is moderate above the 

subsoil and very rapid through it. Available water capacity 

is low. Effective rooting depth is limited by the gravelly 

coarse sand that is at a depth of about 45 inches. Runoff 

is very slow, and the hazard of water erosion is slight. This 

soil is subject to occasional periods of flooding from 

January to April. 

This unit is used as rangeland and homesites and for 

wildlife habitat. Some small areas are used for irrigated 

pasture and grass or legumes. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and basin wildrye. The production of 

forage is limited by the large stones on the surface. If the 

range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass decreases and the 

proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. Areas that are heavily 

infested with undesirable vegetation can be improved with 

such methods as chaining, railing, beating, chemical 

treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition, but it may be difficult because of cobbles. 

The unit should be seeded using a drill. Removal of rocks 

may be necessary before seeding. Adapted grasses should 

be seeded. 

This unit is limited for livestock watering ponds and other 

water impoundments because of seepage. Water tanks, 

springs, wells, or pipeline systems can be used to provide 

water for livestock. 

The main limitations for irrigated pasture are the low 

available water capacity and large stones. Sprinkler irrigation 

systems are suited to the soil in this unit. Use of sprinkler 

irrigation permits the even, controlled application of water. 

To avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. Before tilling or seeding, removal 

of cobbles may be necessary. Dikes can be used to divert 

floodwater. 
This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Dikes and 

channels that have outlets to bypass floodwater can be 

used to protect buildings. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. Cutbanks 

are not stable and are subject to caving in. 

The main limitations for septic tank absorption fields are 

the hazard of flooding and seepage. If the density of 

housing is moderate to high, community sewage systems 

are needed to prevent contamination of water supplies as a 

result of seepage from onsite sewage disposal systems. 

This map unit is in capability subclasses Illw, irrigated, and 

VIw, nonirrigated. 

71-Loneridge stony loam, 0 to 25 percent slopes. 

This very deep, well drained soil is on ridges, benches, and 

mountaintops. It formed in residuum and colluvium derived 

dominantly from basalt that contains small amounts of loess. 

The native vegetation is mainly conifers, grasses, forbs, 

and shrubs. Elevation is 3,200 to 4,500 feet. The average 

annual precipitation is 25 to 40 inches, the average annual 

air temperature is about 43 degrees F, and the average 

length of the growing season, at 28 degrees F, is 145 to 170 

days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The surface 

layer is dark grayish brown stony loam about 3 inches thick. 

The upper part of the subsoil is pale brown very cobbly loam 

about 20 inches thick, and the lower part to a depth of 60 

inches or more is dark yellowish brown and yellowish brown 

very cobbly clay. 

Included in this unit are areas of Bocker soils, areas of 

Rock outcrop, and small convex areas of Loneridge soils 

that have slopes of more than 25 percent. Included areas 

make up about 5 percent of the total acreage. 

Permeability of this Loneridge soil is moderate above 

the lower part of the subsoil and slow through it. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is slow, and the hazard of water 

erosion is slight to moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. Among the trees of limited extent are 

western larch and grand fir. On the basis of a 100-year 

site curve, the mean site index is 75 for ponderosa pine 

and 86 for Douglas-fir. On the basis of a 50-year site curve, 

the mean site index for western larch is 61. Yield tables for 

normal, even-aged, unmanaged stands indicate that the 

mean annual increment at culmination (CMAI) for trees 0.6 

inch in diameter and larger is 62 cubic feet per acre for 

ponderosa pine at age 45 and 79 cubic feet per acre for 

Douglas-fir at age 40. The mean annual increment for trees 

6.6 inches in diameter and larger at 80 years of 

age is 50 cubic feet per acre for ponderosa pine and 65 

cubic feet per acre for Douglas-fir. However, the typical 

basal area of stands on this unit is about 55 percent that of 

normal stands, and the total yield is correspondingly lower. 

The main limitation for the harvesting of timber is a short 

period of seasonal soil wetness. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads 

require suitable surfacing for year-round use. Rock for road 

construction generally is available on this unit. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine and Douglas-fir seedlings. If seed 

trees are present, natural reforestation of cutover areas by 

ponderosa pine and Douglas-fir occurs periodically. The 

droughtiness of the soil increases seedling mortality, 

especially on south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, Oregon-grape, pinemat manzanita, and 

common snowberry. The crown density in the areas where 

the woodland site index was measured is 25 percent. This 

unit is well suited to grazing and browsing. Seeding to 

adapted grazable vegetation following logging or burning late 

in summer or in fall generally is most successful. 

This map unit is in capability subclass Vls, 

nonirrigated. 

72-Loneridge stony loam, 25 to 45 percent slopes. 

This very deep, well drained soil is on mountainsides and 

ridges. It formed in residuum and colluvium derived 

dominantly from basalt that contains small amounts of 

loess. Areas generally are on south-facing slopes. The 

native vegetation is mainly conifers, grasses, and shrubs. 

Elevation is 3,200 to 4,800 feet. The average annual 

precipitation is 25 to 40 inches, the average annual air 

temperature is about 43 degrees F, and the average length 

of the growing season, at 28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The 

surface layer is dark grayish brown stony loam about 3 

inches thick. The upper part of the subsoil is pale brown 

very cobbly loam about 20 inches thick, and the lower part 

to a depth of 60 inches or more is dark yellowish brown and 

yellowish brown very cobbly clay. 

Included in this unit are areas of Bocker soils, areas of 

Rock outcrop, small concave areas of Loneridge soils that 

have slopes of less than 25 percent, and a few areas of 

Loneridge soils that have short slopes of more than 45 

percent. Included areas make up about 5 percent of the total 

acreage. 

Permeability of this Loneridge soil is moderate above 

the lower part of the subsoil and slow through it. 
Available water capacity is moderate. Effective rooting 

depth is 60 inches or more. Runoff is medium, and the 

hazard of water erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. Among the trees of limited extent are 

grand fir, lodgepole pine, and western larch. On the basis of 

a 100-year site curve, the mean site index is 80 for 

ponderosa pine, 92 for Douglas-fir, and 90 for grand fir. 

Yield tables for normal, even-aged, unmanaged stands 

indicate that the mean annual increment at culmination 

(CMAI) for trees 0.6 inch in diameter and larger is 69 cubic 

feet per acre for ponderosa pine at age 40 and 88 cubic feet 

per acre for Douglas-fir at age 40. The mean annual 

increment for trees 6.6 inches in diameter and larger at 80 

years of age is 55 cubic feet per acre for ponderosa pine 

and 75 cubic feet per acre for Douglas-fir. However, the 

typical basal area of stands on this unit is about 80 percent 

that of normal stands, and the total yield is correspondingly 

lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. Cable yarding systems 

may be safer, and they disturb the soil less. Unsurfaced 

roads and skid trails are slippery when wet, and they may 

be impassable during spring runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round 

use. Rock for road construction generally is available on this 

unit. 

Seeding establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine and Douglas-fir seedlings. If 

seed trees are present, natural reforestation of cutover areas 

by ponderosa pine and Douglas-fir occurs periodically. The 

droughtiness of the soil increases seedling mortality, 

especially on south- and southwest-facing slopes. 

Among the common forest understory plants are elk 

sedge, pinegrass, Oregon-grape, pinemat manzanita, lupine, 

and oceanspray. The crown density in the areas where the 

woodland site index was measured is 30 percent. This unit is 

suited to grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

73-Loneridge stony loam, 25 to 45 percent north 

slopes. This very deep, well drained soil is on 

mountainsides and ridges. It formed in residuum and 

colluvium that are derived dominantly from basalt and 

contain small amounts of loess. The native vegetation is 

mainly conifers, grasses, and shrubs. Elevation is 

2,400 to 3,400 feet. The average annual precipitation is 25 

to 

40 inches, the average annual air temperature is about 42 

degrees F, and the average length of the growing season, 

at 28 degrees F, is 135 to 160 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The 

surface layer is dark grayish brown stony loam about 3 

inches thick. The upper part of the subsoil is pale brown 

very cobbly loam about 20 inches thick, and the lower part 

to a depth of 60 inches or more is dark yellowish brown and 

yellowish brown very cobbly clay. 

Included in this unit are areas of Bocker soils, areas of 

Rock outcrop, and small concave areas of Loneridge soils 

that have slopes of less than 25 percent or more than 45 

percent. Included areas make up about 5 percent of the total 

acreage. 

Permeability of this Loneridge soil is moderate above the 

lower part of the subsoil and slow through it. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Douglas-fir and ponderosa pine are the main woodland 

species on this unit. On the basis of a 100-year site curve, 

the mean site index is 96 for Douglas-fir and 80 for 

ponderosa pine. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 95 cubic feet per acre for Douglas-fir at age 40 and 

69 cubic feet per acre for ponderosa pine at age 40. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 110 cubic feet per acre for 

Douglas-fir and 70 cubic feet per acre for ponderosa pine. 

However, the typical basal area of stands on this unit is 

about 70 percent that of normal stands, and the total yield is 

correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. Cable yarding systems may be 

safer, and they disturb the soil less. Unsurfaced roads and 

skid trails are slippery when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads require suitable surfacing for year-round use. Rock for 

road construction generally is available on this unit. The 

north-facing side slopes of this unit retain a snowpack, which 

delays access in spring. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting Douglas-fir and ponderosa pine seedlings. If seed 

trees are present, natural reforestation of cutover areas by 

Douglas-fir and ponderosa pine occurs periodically. The 

droughtiness of the soil increases seedling mortality. 

The common forest understory plants are pinegrass, elk 

sedge, lupine, oceanspray, and common snowberry. The 

crown density in the areas where the woodland site 
index was measured is 40 percent. This unit is suited to 

grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

74-McDaniel very stony loam, 5 to 30 percent slopes. 

This very deep, well drained soil is on uplands. It formed in 

loess and colluvium derived from basalt. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 2,200 to 3,300 feet. The average annual 

precipitation is 15 to 18 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 120 to 135 days. 

Typically, the surface layer is grayish brown very stony 

loam about 8 inches thick. The upper part of the subsoil is 

brown very y gravelly clay loam about 16 inches thick, and 

the lower part to a depth of 60 inches or more is brown very 

cobbly silty clay loam and yellowish brown extremely cobbly 

silty clay loam. In some areas the surface layer does not 

have stones. 

Included in this unit are areas of Clint, Rock Creek, 

and Taneum soils and areas of Rock outcrop and 

McDaniel soils that have slopes of more than 30 

percent. Included areas make up about 15 percent of the 

total acreage. 

Permeability of this McDaniel soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Idaho fescue. The production of forage is 

limited by large stones. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass and Idaho fescue decreases and the proportion 

of less preferred forage plants such as balsamroot and big 

sagebrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chemical treatment 

and prescribed burning. Seeding is difficult because of 

stoniness. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass Vls, 

nonirrigated. 

75-McDaniel very stony loam, 30 to 65 percent slopes. 

This very deep, well drained soil is on uplands. It formed in 

loess and colluvium derived from basalt. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 2,200 to 3,300 feet. The average annual 

precipitation is 15 to 18 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 120 to 135 days. 

Typically, the surface layer is grayish brown very stony 

loam about 8 inches thick. The upper part of the subsoil is 

brown very gravelly clay loam about 16 inches thick, and the 

lower part to a depth of 60 inches or more is brown very 

cobbly silty clay loam and yellowish brown extremely cobbly 

silty clay loam. In some areas the surface layer does not 

have stones. 

Included in this unit are areas of Clint, Rock Creek, 

and Taneum soils, areas of Rock outcrop, and areas of 

McDaniel soils that have slopes of less than 30 percent. 

Permeability of this McDaniel soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Idaho fescue. The production of forage is 

limited by steepness of slope and large stones. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass and Idaho fescue decreases and 

the proportion of less preferred forage plants such as 

balsamroot and big sagebrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chemical treatment 

and prescribed burning. Steepness of slope limits access by 

livestock and promotes overgrazing of the less sloping areas. 

Proper location of salt licks, stock water tanks, and fences 

promotes more uniform distribution of grazing. 

Seeding is a suitable practice if the range vegetation is in 

poor condition, but it is difficult because of stoniness. Use of 

equipment may be difficult on the steeper slopes. The unit 

should be seeded in fall using a drill or by broadcasting. 

Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

76-McDaniel-Rock Creek complex, 5 to 30 percent 

slopes. This map unit is on uplands. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 2,200 to 

3,300 feet. The average annual precipitation is 15 to 18 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 120 to 135 

days. 

This unit is about 60 percent McDaniel very stony loam 

and about 25 percent Rock Creek very stony silt loam. 

The components of this unit are so intricately intermingled 

that it was not practical to map them separately at the 

scale used. 

Included in this unit are areas of Clint, Taneum, and 

Simcoe soils. Included areas make up about 15 percent of 

the total acreage. 

The McDaniel soil is very deep and well drained. It formed 

in loess and in colluvium derived from basalt. Typically, the 

surface layer is grayish brown very stony loam about 8 

inches thick. The upper part of the subsoil 
is brown very gravelly clay loam about 16 inches thick, 

and the lower part to a depth of 60 inches or more is 

brown very cobbly silty clay loam and yellowish brown 

extremely cobbly silty clay loam. In some areas the 

surface layer is stony. 

Permeability of the McDaniel soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

The Rock Creek soil is very shallow and well drained. It 

formed in loess and in residuum derived from basalt. 

Typically, the surface layer is grayish brown very stony silt 

loam about 2 inches thick. The subsoil is grayish brown and 

brown cobbly and very cobbly clay about 8 inches thick. 

Basalt is at a depth of about 10 inches. Depth to basalt 

ranges from 8 to 15 inches. 

Permeability of the Rock Creek soil is moderately slow. 

Available water capacity is low. Effective rooting depth is 8 

to 15 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on the McDaniel soil is 

mainly bluebunch wheatgrass and Idaho fescue. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass and Idaho fescue decreases and 

the proportion of less preferred forage plants such as 

balsamroot and big sagebrush increases. 

The potential native vegetation on the Rock Creek soil is 

mainly Sandberg bluegrass, stiff sagebrush, and 

eriogonum. If the range is overgrazed, the proportion of 

preferred forage plants such as stiff sagebrush and 

Sandberg bluegrass decreases and the proportion of 

less preferred forage plants such as forbs and annual 

grasses increases. 

The production of forage on the McDaniel soil is limited by 

large stones. Droughtiness and depth to rock are the main 

limitations on the Rock Creek soil. Areas of the McDaniel soil 

that are heavily infested with undesirable vegetation can be 

improved with such methods as chaining, railing, 

beating, chemical treatment, and prescribed burning. 

Range seeding on the Rock Creek soil is not feasible 

because of the very shallow soil depth and soil droughtiness. 

Range seeding on the McDaniel soil is a suitable practice if 

the range vegetation is in poor condition, but it is difficult 

because of stoniness. The soil should be seeded in fall using 

a drill or by broadcasting. Adapted grasses and 

legumes should be seeded on this unit. 

This map unit is in capability subclass 

VIIs, nonirrigated. 

77-Meystre loam, 0 to 15 percent slopes. This very 

deep, well drained soil is on uplands. It formed in loess and 

in material weathered from sandstone. The native 

vegetation is mainly conifers, grasses, forbs, and 

shrubs. Elevation is 2,200 to 3,300 feet. The average annual 

precipitation is 15 to 20 inches, the average annual air 

temperature is about 48 degrees F, and the average length 

of the growing season, at 28 degrees F, is 150 to 175 days.

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The 

surface layer is grayish brown and dark grayish brown loam 

about 11 inches thick. The subsoil is brown and yellowish 

brown clay loam and light yellowish brown fine sandy loam 

about 30 inches thick. The substratum to a depth of 60 

inches or more is light yellowish brown fine sandy loam. In 

some areas the subsoil is clay. 

included in this unit are small areas of Taneum and Odo 

soils and areas of Meystre soils that have slopes of more 

than 15 percent. Included areas make up about 10 percent 

of the total acreage. 

Permeability of this Meystre soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. Among the trees of limited extent is 

Oregon white oak. On the basis of a 100-year site curve, 

the mean site index is 63 for ponderosa pine and 74 for 

Douglas-fir. Yield tables for normal, even-aged, unmanaged 

stands indicate that the mean annual increment at 

culmination (CMAI) for trees 0.6 inch in diameter and larger 

is 49 cubic feet per acre for ponderosa pine at age 55 and 61 

cubic feet per acre for Douglas-fir at age 45. The mean 

annual increment for trees 6.6 inches in diameter and larger 

at 80 years of age is 40 cubic feet per acre for ponderosa 

pine and 50 cubic feet per acre for Douglas-fir. However, the 

typical basal area of stands on this unit is about 80 percent 

that of normal stands, and the total yield is correspondingly 

lower. 

The main limitation for the harvesting of timber is a short 

period of seasonal soil wetness. Wheeled and tracked 

equipment can be used in skidding operations. Use of such 

equipment when the soil is moist can produce ruts, 

compact the soil, and damage tree roots. Unsurfaced roads 

and skid trials are soft when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads require suitable surfacing for year-round use. Rock 

for road construction is not readily available on this unit. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine seedlings. If seed trees are present, 

natural reforestation of cutover areas by ponderosa pine 

occurs infrequently. The droughtiness of the soil increases 

seedling mortality, especially on south- and southwest- facing 

slopes. 

The common forest understory plants are elk sedge, 

pinegrass, Idaho fescue, lupine, antelope bitterbrush, and 

Oregon-grape. The crown density in the areas where the 
woodland site index was measured is 35 percent. This unit 

is well suited to grazing. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This map unit is in capability subclass Ille, nonirrigated. 

78-Meystre stony loam, 15 to 45 percent slopes. This 

very deep, well drained soil is on uplands. It formed in loess 

and in material weathered from sandstone. The native 

vegetation is mainly conifers, grasses, forbs, and shrubs. 

Elevation is 2,200 to 3,300 feet. The average annual 

precipitation is 15 to 20 inches, the average annual air 

temperature is about 48 degrees F, and the average length 

of the growing season, at 28 degrees F, is 150 to 175 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The surface 

layer is grayish brown and dark grayish brown stony loam 

about 11 inches thick. The subsoil is brown and yellowish 

brown clay loam and light yellowish brown fine sandy loam 

about 30 inches thick. The substratum to a depth of 60 

inches or more is light yellowish brown fine sandy loam. 

Included in this unit are areas of Taneum and Odo soils 

and areas of Meystre soils that have slopes of less than 15 

percent. Included areas make up about 10 percent of the 

total acreage. 

Permeability of this Meystre soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main 

woodland species on this unit. On the basis of a 100-year 

site curve, the mean site index is 63 for ponderosa pine and 

74 for Douglas-fir. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 49 cubic feet per acre for ponderosa pine at age 55 

and 61 cubic feet per acre for Douglas-fir at age 45. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 35 cubic feet per acre for 

ponderosa pine and 50 cubic feet per acre for Douglas-fir. 

However, the typical basal area of stands on this unit is 

about 80 percent that of normal stands, and the total yield is 

correspondingly lower. 

The main limitations for the harvesting of timber are a 

short period of seasonal soil wetness and steepness of 

slope. Wheeled and tracked equipment can be used in 

skidding operations. Use of such equipment when the soil is 

moist can produce ruts, compact the soil, and damage tree 

roots, especially on parts of the unit that have slopes of 

more than 30 percent. Unsurfaced roads and skid trails are 

soft when wet, and they may be impassable during spring 

runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round use. 

Rock for road construction is not readily available on this 

unit. Steep skid trails and firebreaks are subject to rilling 

and gullying unless adequate water bars are provided or 

they are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine seedlings. If seed trees are present, 

natural reforestation of cutover areas by ponderosa pine 

occurs infrequently. The droughtiness of the soil increases 

seedling mortality, especially on south- and southwest-facing 

slopes. 

The common forest understory plants are elk sedge, 

pinegrass, Oregon-grape, ceanothus, and common 

snowberry. The crown density in the areas where the 

woodland site index was measured is 25 percent. This unit is 

suited to grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This map unit is in capability subclass VIs, 

nonirrigated. 

79-Mikkalo silt loam, 0 to 5 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,500 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is brown silt loam about 15 inches 

thick. The upper part of the substratum is pale brown silt 

loam about 6 inches thick, and the lower part is pale brown 

gravelly silt loam about 4 inches thick. Basalt is at a depth 

of about 30 inches. Depth to basalt ranges from 20 to 40 

inches. 

Included in this unit are areas of Starbuck soils, 

Ritzville soils that are underlain by basalt, and Willis 

soils. 

Permeability of this Mikkalo soil is moderate. Available 

water capacity is moderately high. Effective rooting depth is 

20 to 40 inches. Runoff is slow, and the hazard of water 

erosion is slight. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitation for nonirrigated crops is low annual 

precipitation. Because precipitation is not sufficient for 

annual cropping, a cropping system that includes winter 

wheat and summer fallow is most suitable. Erosion can be 

reduced by seeding fall grain early, stubble mulching, using 

terraces, and stripcropping. Drainageways should be 

shaped and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Cusick bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage 
plants such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. 

The main limitation is depth to rock, which hinders 

excavation. Dustiness can be a problem during 

construction of large building Sites;

 therefore these sites 

should be disturbed as little as possible. 

If this unit is used for septic tank absorption fields, the 

depth to rock limits the capacity of the absorption fields. The 

use of long absorption lines helps to compensate for this 

limitation. 

This map unit is in capability subclass IVe, 

nonirrigated. 

80-Mikkalo silt loam, 5 to 15 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,500 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is brown silt loam about 15 inches 

thick. The upper part of the substratum is pale brown silt 

loam about 6 inches thick, and the lower part is pale brown 

gravelly silt loam about 4 inches thick. Basalt is at a depth 

of about 30 inches. Depth to basalt ranges from 20 to 40 

inches. 

Included in this unit are areas of Starbuck soils, 

Ritzville soils that are underlain by basalt, and Willis soils. 

Included areas make up about 10 percent of the total 

acreage. 

Permeability of this Mikkalo soil is moderate. Available 

water capacity is moderately high. Effective rooting depth is 

20 to 40 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for nonirrigated cropland, 

rangeland, wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall 

grain early, stubble mulching, tilling on the contour or 

across the slope, using terraces, and stripcropping. Seeding 

on the contour or across the slope slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be 

shaped and seeded to perennial grasses. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Cusick bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. Areas that 

are heavily infested with undesirable vegetation can be 

improved by such methods as chaining, railing, beating, 

chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

pour condition. The unit Should be weeded in fall using 

a drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is depth to rock, which hinders excavation. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

The main limitation for septic tank absorption fields is the 

depth to rock. Bedrock limits the capacity of the absorption 

field. The use of long absorption lines helps to compensate 

for this limitation. Slope can promote lateral seepage and 

surfacing of the effluent in downslope areas. Absorption lines 

should be installed on the contour. 

This map unit is in capability subclass IVe, 

nonirrigated. 

81-Mikkalo silt loam, 15 to 30 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is from 1,200 to 2,500 feet. The average 

annual precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is brown silt loam about 15 inches 

thick. The upper part of the substratum is pale brown silt 

loam about 6 inches thick, and the lower part is pale brown 

gravelly silt loam about 4 inches thick. Basalt is at a depth 

of about 30 inches. Depth to basalt ranges from 20 to 40 

inches. 

Included in this unit are areas of Starbuck soils, 

Ritzville soils that are underlain by basalt, and Willis soils. 

Included areas make up about 15 percent of the total 

acreage. 

Permeability of this Mikkalo soil is moderate. Available 

water capacity is moderately high. Effective rooting depth is 

20 to 40 inches. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be 
reduced by seeding fall grain early, stubble mulching, and 

tilling and seeding on the contour or across the slope. 

Drop structures are needed in places to control the flow 

of runoff in waterways. Waterways should be shaped and 

seeded to perennial grasses. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Cusick bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. Areas 

that are heavily infested with undesirable shrubs can be 

improved by such methods as chaining, railing, beating, 

chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. 

The main limitations are the moderate depth to rock and 

steepness of slope. The bedrock hinders excavation. 

Dustiness can be a problem during construction on large 

building sites; therefore these sites should be disturbed as 

little as possible. 

The main limitations for septic tank absorption fields are 

the moderate depth to rock and steepness of slope. The 

moderate depth to bedrock limits the capacity of the 

absorption fields and, along with slope, can promote lateral 

seepage and surfacing of effluent in downslope areas. Use 

of long absorption lines helps to compensate for the 

moderate depth to bedrock. Absorption lines should be 

installed on the contour. 

This map unit is in capability subclass IVe, 

nonirrigated. 

82-Mippon very cobbly silt loam. This very deep, well 

drained soil is on low terraces and flood plains. It formed in 

recent alluvium. Slope is 0 to 5 percent. Areas are long and 

narrow. They are characterized by old dry streambeds. The 

native vegetation is mainly coniferous and deciduous 

trees, grasses, forbs, and shrubs. Elevation is 2,400 to 

4,800 feet. The average annual precipitation is 20 to 40 

inches, the average annual air temperature is about 43 

degrees F, and the average length of the growing season, 

at 28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1/2 inch thick. The 

upper 7 inches of the surface layer is very dark grayish 

brown very cobbly silt loam, and the lower 7 inches is dark 

grayish brown very cobbly loam. The substratum to a depth 

of 60 inches or more is brown and yellowish brown 

extremely gravelly sand. In some areas the surface layer is 

stony or extremely cobbly, the substratum is loam or sandy 

loam, or the soil is mottled and has a seasonal high water 

table in the lower part of the substratum. 

Included in this unit are areas of riverwash along stream 

channels and in old dry streambeds. Also included are 

areas of poorly drained soils in depressional areas. Included 

areas make up about 15 percent of the total acreage. 

Permeability of this Mippon soil is very rapid. Available 

water capacity is low. Effective rooting depth is 60 inches or 

more. Runoff is slow, and the hazard of water erosion is 

slight. A seasonal high water table is at a depth of 36 to 60 

inches during February to April. This soil is subject to 

occasional periods of flooding from March to May. 

Channeling and deposition are common along streambanks. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main coniferous 

species at the lower elevations on this unit. Grand fir is the 

predominant coniferous species above an elevation of 3,000 

feet. Trees of limited extent include western larch, lodgepole 

pine, and Engelmann spruce. On the basis of a 100-year site 

curve, the mean site index is 108 for ponderosa pine, 113 for 

Douglas-fir, 104 for grand fir, and 87 for lodgepole pine. 

Yield tables for normal, even-aged, unmanaged stands 

indicate that the mean annual increment at culmination 

(CMAI) for trees 0.6 inch in diameter and larger at age 40 is 

118 cubic feet per acre for ponderosa pine and 128 cubic 

feet per acre for Douglas-fir. The mean annual increment for 

trees 6.6 inches in diameter and larger at 80 years of age is 

105 cubic feet per acre for ponderosa pine and 135 cubic 

feet per acre for Douglas-fir. However, the typical basal area 

of stands on this unit is about 85 percent that of normal 

stands, and the total yield is correspondingly lower. 

The main limitations for the harvesting of timber are the 

uneven, broken topography, occasional periods of flooding, 

and the very cobbly surface layer. Use of equipment is 

limited by the occasional periods of flooding in spring. 

Routes for roads and skid trails commonly are restricted by 

old stream channels. Leveling and grading the surface layer 

generally are adequate for road construction on this unit. 

Extra caution is required during felling and yarding to prevent 

damage to streambeds, streambanks, and riparian 

vegetation. The large volume of cobbles in the surface layer 

increases the wear of wheeled and tracked equipment. 

Plant competition is the main concern in the production of 

timber. Varying amounts of black cottonwood, mountain 

alder, quaking aspen, redosier dogwood, and willow are 

in the included areas of this unit. These brushy plants can 

invade openings on the Mippon soil in this unit and, unless 

controlled, delay reforestation. The droughtiness of the 

surface layer during the dry summer months increases 

seedling mortality. Reforestation can be accomplished by 

planting ponderosa pine and Douglas-fir seedlings. If seed 

trees 
are present, natural reforestation of cutover areas by 

ponderosa pine and Douglas-fir occurs periodically. 

The common forest understory plants are oceanspray, 

common snowberry, elderberry, currant, rose, redosier 

dogwood, and elk sedge. The crown density in the areas 

where the woodland site index was measured is 30 percent. 

This unit is well suited to grazing and browsing. If the 

understory is overgrazed, the proportion of preferred forage 

plants such as elk sedge decreases and the proportion of 

less desirable forbs and annual grasses increases. Seeding 

to adapted grazable vegetation following logging or burning 

late in summer or in fall generally is most successful. 

This map unit is in capability subclass Vlw, 

nonirrigated. 

83-Moxee silt loam, 2 to 15 percent slopes. This 

well drained soil is on uplands. It is shallow over a 

hardpan. It formed in loess. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,300 to 

2,000 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 125 to 160 

days. 

Typically, the surface layer is brown silt loam about 7 

inches thick. The subsoil is pale brown silt loam about 4 

inches thick. The substratum is pale brown gravelly silt loam 

about 7 inches thick. A lime- and silica-cemented hardpan 

is at a depth of about 18 inches. Depth to the hardpan 

ranges from 10 to 20 inches. The hardpan commonly is 

underlain by basalt. In some areas the surface layer is fine 

sandy loam. 

Included in this unit are small areas of Starbuck, 

Selah, Roza, Willis, and Gorst soils. 

Permeability of this Moxee soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

low. Effective rooting depth is 10 to 20 inches. Runoff is 

medium, and the hazard of water erosion is moderate. 

This unit is used for irrigated pasture and hay, 

rangeland (fig. 3), wildlife habitat, and 

homesites. 

The main limitations for irrigated pasture and hay are 

steepness of slope, depth to the hardpan, and the hazard of 

water erosion. Using a cropping system that includes closegrowing crops in the rotation reduces water erosion. Sprinkler 

irrigation systems are well suited to the soil in this unit. Use 

of these systems permits the even, controlled application of 

irrigation water, reduces runoff, and minimizes the risk of 

erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should be adjusted to the available water capacity and the 

crop needs. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass and Sandberg bluegrass. The 

production of forage is limited by the depth to the 

hardpan. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage 

plants such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed burning.

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is the shallow depth to the hardpan, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

shallow depth to the hardpan, which limits the capacity of 

the absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclasses IVe, irrigated, and 

Vle, nonirrigated. 

84-Moxee silt loam, 15 to 30 percent slopes. This 

well drained soil is on uplands. It is shallow over a hardpan. 

It formed in loess. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 1,300 to 2,000 feet. The 

average annual precipitation is 8 to 12 inches, the average 

annual air temperature is 49 degrees F, and the average 

frost-free season is 125 to 160 days. 

Typically, the surface layer is brown silt loam about 7 

inches thick. The subsoil is pale brown silt loam about 4 

inches thick. The substratum is pale brown gravelly silt loam 

about 7 inches thick. A lime- and silica-cemented hardpan 

is at a depth of about 18 inches. Depth to the hardpan 

ranges from 10 to 20 inches. The hardpan commonly is 

underlain by basalt. 

Included in this unit are small areas of Starbuck, Willis, 

Selah, and Gorst soils and areas of Moxee soils that have 

slopes of more than 30 percent. 

Permeability of this Moxee soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 10 to 20 inches. Runoff is 

rapid, and the hazard of water erosion is high. 

This unit is used for irrigated hay and pasture, for 

wildlife habitat, and as homesites. 

The main limitations for irrigated hay and pasture are 

steepness of slope, depth to the hardpan, and the hazard of 

water erosion. Using a cropping system that includes closegrowing crops in the rotation reduces water erosion. 

Sprinkler irrigation systems are suited to the soil in this unit. 

Use of these systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should be adjusted to the available water capacity, the water 

intake rate, and the crop needs. 
 

Figure 3.-Rangeland on Moxee silt loam, 2 to 15 percent slopes, in the foreground. 

This unit is poorly suited to homesite development. The 

main limitations are the shallow depth to the hardpan and 

steepness of slope. The pan hinders excavation. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

depth to the hardpan and steepness of slope. The pan limits 

the capacity of the absorption fields. Use of long absorption 

lines helps to compensate for this limitation. Slope can 

cause lateral seepage and surfacing of effluent in downslope 

areas. 

This map unit is in capability subclass Vle, irrigated. 

85-Moxee cobbly silt loam, 0 to 30 percent slopes. 

This well drained soil is on uplands. It is shallow over a 

hardpan. It formed in loess. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 1,300 

to 2,000 feet. The average annual precipitation is 8 to 12

inches, the average annual air temperature is 49 degrees F, 

and the average frost-free season is 125 to 160 days. 

Typically, the surface layer is brown cobbly silt loam about 

7 inches thick. The subsoil is pale brown silt loam about 4 

inches thick. The substratum is pale brown gravelly silt loam 

about 7 inches thick. A lime- and silica-cemented hardpan is 

at a depth of about 18 inches. Depth to the hardpan ranges 

from 10 to 20 inches. The hardpan commonly is underlain 

by basalt. 

Included in this unit are areas of Starbuck and Gorst 

soils. 

Permeability of this Moxee soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 10 to 20 inches. Runoff is 

medium, large stones, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated hay and pasture, 

rangeland, wildlife habitat, and homesites. 
The main limitations for irrigated hay and pasture are 

steepness of slope, depth to the hardpan, large stones, and 

the hazard of water erosion. Sprinkler irrigation systems are 

suited to the soil in this unit. Use of these systems permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. Growing 

perennial hay and pasture reduces erosion. Seedbed 

preparation is difficult, and removal of stones might be 

necessary. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production of 

forage is limited by large stones and the low available water 

capacity. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and cheatgrass increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as chaining, 

railing, chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition, but it is difficult because of the cobbles in 

the surface layer. Removal of stones may be needed 

before seeding. The unit should be seeded in the fall using 

a drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are the shallow depth to the hardpan, 

steepness of slope, and large stones, which hinder 

excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. The cobbly surface 

makes the establishment of lawns difficult. 

The main limitations for septic tank absorption fields are 

depth to the hardpan and steepness of slope. The hardpan 

limits the capacity of the absorption fields. Use of long 

absorption lines helps to compensate for this limitation. Slope 

can cause lateral seepage and surfacing of the effluent in 

downslope areas. Absorption lines should be installed on the 

contour. 

This map unit is in capability subclass Vle, nonirrigated and 

irrigated. 

86-Naches loam. This very deep, well drained soil is on 

stream terraces in valleys. It formed in old alluvium. Slope is 

0 to 2 percent. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 700 to 900 feet. The average 

annual precipitation is 7 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is grayish brown loam about 9 

inches thick. The upper part of the subsoil is brown loam 

about 12 inches thick, and the lower part is yellowish 

brown loam about 7 inches thick. The upper part of the 

substratum is yellowish brown gravelly loam 

about 6 inches thick, and the lower part to a depth of 60 

inches or more is dark grayish brown extremely gravelly 

sand. In some areas the surface layer is gravelly, and in 

some areas the substratum is extremely gravelly to a depth 

of about 38 inches or more. 

Included in this unit are small areas of Esquatzel, 

Ashue, and Yakima soils. 

Permeability of this Naches soil is slow above the lower 

part of the substratum and very rapid through it. Available 

water capacity is moderately high. Effective rooting depth 

is 60 inches or more. Runoff is very slow, and the hazard 

of water erosion is slight. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are corn, grain, grapes, hops, mint, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and seed.

This unit has few limitations for irrigated crops. Furrow, 

corrugation, drip, and sprinkler irrigation systems are suited 

to the soil is this unit. The type of system used depends on 

the kind of crop grown. Use of sprinkler or drip irrigation 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. If surface irrigation 

systems are used, the risk of erosion can be minimized by 

keeping runs short. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity and 

the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using vegetated filter strips at the end of rows or using 

sediment ponds, or both, reduces the volume of sediment in 

the tailwater. 

This unit is well suited to homesite development. It has 

few limitations. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Cutbanks are not 

stable and are subject to caving in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage 

from onsite sewage disposal systems. 

This map unit is in capability subclass lls, irrigated. 

87-Naxing loam, 5 to 25 percent slopes. This very 

deep, well drained soil is on mountaintops and broad 

mountain ridges. It formed in colluvium that is derived 

dominantly from basalt and contains small amounts of loess 

and volcanic ash. The native vegetation is mainly conifers, 

forbs, and shrubs. Elevation is 5,000 to 7,000 feet. The 

average annual precipitation is 40 to 50 inches, the average 

annual air temperature is about 41 degrees F, and the 

average length of the growing season, at 28 degrees F, is 80 

to 110 days. 
Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The surface 

layer is brown loam about 14 inches thick. The subsoil is 

yellowish brown very cobbly loam about 7 inches thick. The 

substratum to a depth of 60 inches or more is yellowish 

brown extremely cobbly loam. In some areas the surface 

layer is stony. 

Included in this unit are areas of Cryandepts in swales and 

on alluvial fans, Saydab soils on ridgetops, Darland soils on 

south-facing side slopes, and Naxing soils that have slopes 

of more than 25 percent. Also included are soils, on cirque 

floors, that have a glacial till substratum. Included areas 

make up about 10 percent of the total acreage. 

Permeability of this Naxing soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Subalpine fir, lodgepole pine, and Engelmann spruce 

are the main woodland species on this unit. Among the trees 

of limited extent are whitebark pine and western larch. 

Western larch and lodgepole pine commonly occur in small, 

densely stocked stands. On the basis of a 100-year site 

curve, the mean site index is 70 for lodgepole pine, 68 for 

subalpine fir, and 74 for Engelmann spruce. Yield tables for 

normal, even-aged, unmanaged stands of lodgepole pine 

at 100 years of age indicate that the mean annual increment 

at culmination (CMAI) is 70 cubic feet per acre. On the basis 

of a 50-year site curve, the mean site index for western larch 

is 55. Yield tables for normal, even-aged, unmanaged 

stands of western larch indicate that the mean annual 

increment at culmination for trees 0.6 inch in diameter and 

larger at 70 years of age is 72 cubic feet per acre. The mean 

annual increment for western larch trees 7.6 inches in 

diameter and larger at 80 years of age is 40 cubic feet per 

acre. However, the typical basal area of stands on this unit is 

about 125 percent that of normal stands, and total yield is 

correspondingly higher. The site index is quite variable on 

this unit. The highest site indexes generally are at the lower 

elevations on south-facing slopes, and the lowest site 

indexes are at the higher elevations on north-facing slopes. 

The main limitation for the harvesting of timber is 

snowpack, which hinders the use of equipment and limits 

access in winter. Wheeled and tracked equipment can be 

used in skidding operations. Unsurfaced roads and skid trails 

are soft and slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads 

require suitable surfacing for year-round use. Rock for 

road construction is available in some areas of this unit. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by subalpine fir and 

lodgepole pine occurs periodically. Low soil temperatures, 

heavy snowpack, and the short growing season limit the 

even distribution of natural reforestation, especially on northfacing slopes. The droughtiness of the surface layer during 

the dry summer months increases seedling mortality, 

especially on south- and southwest- facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, vetch, and dwarf huckleberry. The 

crown density in the areas where the woodland site index 

was measured is 40 percent. This unit is well suited to 

grazing and browsing. It has few limitations for the 

production of forage. If the understory is overgrazed, the 

proportion of preferred forage plants such as elk sedge 

decreases and the proportion of less desirable forbs and 

annual grasses increases. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This unit is limited for livestock watering ponds and other 

water impoundments because of seepage. Spring 

developments, wells, or pipeline systems can be used to 

provide stock water. 

This map unit is in capability subclass Vle, 

nonirrigated. 

88-Naxing stony loam, 25 to 45 percent slopes. This 

very deep, well drained soil is on mountainsides. It formed 

in colluvium that is derived dominantly from basalt and 

contains loess and volcanic ash. The native vegetation is 

mainly conifers, forbs, and shrubs. Elevation is 5,000 to 

7,000 feet. The average annual precipitation is 40 to 50 

inches, the average annual air temperature is about 41 

degrees F, and the average length of the growing season, 

at 28 degrees F, is 80 to 110 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The surface 

layer is brown stony loam about 14 inches thick. The subsoil 

is yellowish brown very cobbly loam about 7 inches thick. 

The substratum to a depth of 60 inches or more is yellowish 

brown extremely cobbly loam. 

Included in this unit are areas of Saydab soils on 

ridgetops, areas of Darland soils on south-facing side slopes, 

areas of Rock outcrop, and areas of Naxing soils that have 

slopes of less than 25 percent or more than 45 percent. 

Included areas make up about 10 percent of the total 

acreage. 

Permeability of this Naxing soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Western larch, subalpine fir, and lodgepole pine are the 

main woodland species on this unit. Among the trees of 

limited extent are grand fir, Engelmann spruce, and 

whitebark pine. On the basis of a 50-year site curve, the 
mean site index for western larch is 52. Yield tables for 

normal, even-aged, unmanaged stands of western larch 

indicate that the mean annual increment at culmination 

(CMAI) for trees 0.6 inch in diameter and larger at 70 years 

of age is 67 cubic feet per acre. The mean annual increment 

for western larch trees 7.6 inches in diameter and larger at 

80 years of age is 35 cubic feet per acre. On the basis of a 

100-year site curve, the mean site index is 85 for lodgepole 

pine, 75 for subalpine fir, and about 74 for Engelmann 

spruce. Yield tables for normal, even-aged, unmanaged 

stands of lodgepole pine at 100 years of age indicate that 

the mean annual increment at culmination is about 97 cubic 

feet per acre. However, the typical basal area of stands on 

this unit is about 95 percent that of normal stands, and the 

total yield is correspondingly lower. The site index is quite 

variable on this unit. The highest site indexes generally are 

at the lower elevations on south-facing slopes, and the 

lowest site indexes are at the higher elevations on northfacing slopes. 

The main limitations for the harvesting of timber are 

snowpack and steepness of slope. Snowpack hinders the 

use of equipment and limits access in winter. North-facing 

side slopes retain snowpack longer, which delays access in 

spring. Steepness of slope makes the use of wheeled and 

tracked equipment difficult. Cable yarding systems may be 

safer, and they disturb the soil less. Unsurfaced roads and 

skid trails are soft and slippery when wet, and they may be 

impassable during spring runoff or in rainy periods. Logging 

roads require suitable surfacing for year-round use. Rock for 

road construction is available in some areas of this unit. 

Steep yarding paths, skid trails, and firebreaks are subject to 

rilling and gullying unless adequate water bars are provided 

or they are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by subalpine fir and western 

larch occurs periodically. Low soil temperatures, deep 

snowpack, and the short growing season limit the even 

distribution of natural reforestation, especially on northfacing slopes. The droughtiness of the surface layer during 

the dry summer months increases seedling mortality, 

especially on south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, vetch, currant, and dwarf huckleberry. 

The crown density in the areas where the woodland site 

index was measured is 40 percent. This unit is well suited to 

grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This unit is limited for livestock watering ponds and other 

water impoundments because of seepage. Spring 

developments, wells, or pipeline systems can be used to 

provide stock water. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

89-Naxing stony loam, 45 to 65 percent slopes. 

This very deep, well drained soil is on mountainsides. It 

formed in colluvium that is derived dominantly from basalt 

and contains loess and volcanic ash. The native vegetation 

is mainly conifers, forbs, and shrubs. Elevation is 5,000 to 

7,000 feet. The average annual precipitation is 40 to 50 

inches, the average annual air temperature is about 41 

degrees F, and the average length of the growing season, 

at 28 degrees F, is 80 to 110 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The 

surface layer is brown stony loam about 14 inches thick. 

The subsoil is yellowish brown very cobbly loam about 7 

inches thick. The substratum to a depth of 60 inches or 

more is yellowish brown extremely cobbly loam. 

Included in this unit are Saydab soils on ridgetops, 

Darland soils on south-facing side slopes, areas of Rock 

outcrop, and Naxing soils on concave slopes of less than 

45 percent. Included areas make up about 15 percent of 

the total acreage. 

Permeability of this Naxing soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Subalpine fir, Engelmann spruce, and western larch are the 

main woodland species on this unit. Among the trees of 

limited extent are whitebark pine, Douglas-fir, and grand fir. 

On the basis of a 50-year site curve, the mean site index for 

western larch is 52. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger at 70 years of age is 67 cubic feet per acre. The 

mean annual increment for trees 7.6 inches in diameter and 

larger at 80 years of age is 35 cubic feet per acre. However, 

the typical basal area of stands on this unit is about 90 

percent that of normal stands, and the total yield is 

correspondingly lower. On the basis of 100-year site 

curve, the site index is 59 for subalpine fir and about 74 

for Engelmann spruce. The site index is quite variable on 

this unit. The highest site indexes generally are at the lower 

elevations on south-facing slopes, and the lowest site 

indexes are at the higher elevations on north-facing slopes. 

The main limitations for the harvesting of timber are 

snowpack and steepness of slope. Snowpack hinders the 

use of equipment and limits access in winter. North-facing 

side slopes retain snowpack longer, which delays access in 

spring. Steepness of slope restricts the use of wheeled and 

tracked equipment in skidding operations; cable yarding 

systems are safer and disturb the soil less. Unsurfaced 

roads and skid trails are soft and slippery 
when wet, and they may be impassable during spring runoff 

or in rainy periods. Logging roads require suitable surfacing 

for year-round use. Rock for road construction is available 

in some areas of this unit. Steep yarding paths, skid trails, 

and firebreaks are subject to rilling and gullying unless 

adequate water bars are provided or they are protected by 

plant cover. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by subalpine fir and 

Engelmann spruce occurs periodically. Low soil 

temperatures, deep snowpack, and the short growing 

season increase seedling mortality and limit the even 

distribution of natural reforestation, especially on northfacing slopes. The droughtiness of the surface layer during 

the dry summer months increases seedling mortality, 

especially on south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, vetch, currant, pinemat manzanita, 

and dwarf huckleberry. The crown density in the areas where 

the woodland site index was measured is 30 percent. This 

unit is well suited to browsing. Steepness of slope limits 

access by livestock. Seeding to adapted grazable vegetation 

following logging or burning late in summer or inn fall 

generally is most successful. Because of the steepness of 

slope, broadcast seeding should be used. 

This unit is limited for livestock watering ponds and 

other water impoundments because of seepage potential. 

Spring developments, wells, or pipeline systems can be 

used to provide stock water. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

90-Odo cobbly silt loam, 5 to 35 percent slopes. 

This very deep, well drained soil is on uplands. It formed in 

residuum and colluvium that is derived dominantly from 

basalt and contains some loess and volcanic ash. The 

native vegetation is mainly conifers, grasses, forbs, and 

shrubs. Elevation is 2,000 to 3,200 feet. The average 

annual precipitation is 15 to 19 inches, the average annual 

air temperature is about 46 degrees F, and the average 

length of the growing season, at 28 degrees F, is 150 to 

180 days. 

Typically, the surface is covered with a mat of 

decomposing organic material about 3 inches thick. The 

surface layer is brown cobbly silt loam about 18 inches thick. 

The subsoil to a depth of 60 inches or more is yellowish 

brown gravelly loam. In some areas the subsoil is very 

gravelly or very cobbly. 

Included in this unit are areas of Meystre, Rock Creek, 

Clint, and Tekison soils. Included areas make up about 10 

percent of the total acreage. 

Permeability of the Odo soil is moderate. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is medium, and hazard of water erosion is 

moderate. 

The unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. Among the trees of limited extent are 

Oregon white oak and Rocky Mountain maple. On the basis 

of a 100-year site curve, the mean site index is 75 for 

ponderosa pine and 96 for Douglas-fir. Yield tables for 

normal, even-aged, unmanaged stands indicate that the 

mean annual increment at culmination (CMAI) for trees 0.6 

inch in diameter and larger is 62 cubic feet per acre for 

ponderosa pine at age 45 and 95 cubic feet per acre for 

Douglas fir at age 40. The mean annual increment for trees 

6.6 inches in diameter and larger at 80 years of age is 50 

cubic feet per acre for ponderosa pine and 80 cubic feet per 

acre for Douglas-fir. However, the typical basal area of 

stands on this unit is about 70 percent that of normal 

stands, and the total yield is correspondingly lower. 

The main limitation for the harvesting of timber is a short 

period of seasonal soil wetness. Use of wheeled and 

tracked equipment when the soil is moist can produce ruts, 

compact the soil, and damage tree roots. Unsurfaced roads 

and skid trails are soft and slippery when wet, and they may 

be impassable during spring runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round use. 

Rock for road construction is not readily available on this 

unit. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine seedlings. Where seed trees are 

present, natural reforestation of cutover areas by ponderosa 

pine occurs infrequently. Droughtiness of the soil increases 

seedling mortality, especially on south- and southwest- facing 

slopes. 

The common forest understory plants are elk sedge, 

pinegrass, bitterbrush, common snowberry, and Oregon 

white oak. The crown density in the areas where the 

woodland site index was measured is 25 percent. This unit 

is well suited to grazing and browsing. Seeding to adapted 

grazable vegetation following logging or burning late in 

summer or in fall generally is most successful. 

This map unit is in capability subclass IVe, 

nonirrigated. 

91-Outlook fine sandy loam. This very deep, artificially 

drained soil is on flood plains. It formed in alluvium. Slope 

is 0 to 3 percent. The native vegetation is mainly alkalitolerant grasses and shrubs. Elevation is 650 to 2,000 feet. 

The average annual precipitation is 6 to 12 inches, the 

average annual air temperature is 51 degrees F, and the 

average frost-free season is 130 to 160 days. 

Typically, the surface layer is very dark grayish brown, 

dark grayish brown, and very dark brown fine sandy loam 

about 8 inches thick and has yellowish brown or dark 

yellowish brown mottles. It is strongly alkaline. The subsoil is 

grayish brown, mottled silt loam about 10 
inches thick. The substratum to a depth of 60 inches or more 

is dark brown silt loam. The subsoil and substratum are 

moderately alkaline. 

Included in this unit are small areas of Umapine and 

Sinloc soils and areas of Outlook soils that have not been 

artificially drained. 

Permeability of this Outlook soil is moderate. Available 

water capacity is high. Effective rooting depth is limited by a 

high water table that is at a depth of 24 to 48 inches from 

May to December. Runoff is ponded, and the hazard of 

erosion is slight. The hazard of soil blowing is high. This soil 

is partially protected from flooding, and the hazard of flooding 

is rare. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. In areas that have been drained, leached, and 

irrigated, the main crops are asparagus, corn, grain, hops, 

and mint. Grasses and legumes are grown for hay, pasture, 

and seed. Deep-rooted crops are suited to areas where the 

drainage is adequate or where a drainage system has been 

installed and is adequately maintained. 

The main limitations for irrigated crops are wetness, high 

alkalinity, and the hazard of soil blowing. Dikes can be used 

to divert floodwater. Reclamation may require the addition 

of such amendments as gypsum, sulfur, or ferric sulfate to 

facilitate leaching. 

Furrow, corrugation, and sprinkler irrigation systems are 

suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. Use of sprinkler 

irrigation systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. If 

surface irrigation systems are used, the risk of erosion can 

be minimized by keeping runs short. To avoid loss of water 

and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity, the water intake rate, and the crop 

needs. 

The initial period of irrigation following cultivation is the 

most critical one for the control of erosion. The hazard of 

soil blowing makes proper tillage and crop residue 

management extremely important. This unit should be 

protected with plant cover or residue during the period of 

susceptibility to soil blowing in spring. Seedbeds should be 

prepared when irrigation water is available to saturate the soil 

surface. Use of straw, manure, or other waste material as a 

mulch reduces soil blowing. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation and maintaining crop 

residue on the surface reduce erosion. Using vegetated filter 

strips at the end of rows or using sediment ponds, or both, 

reduces the amount of sediment in the tailwater. A plowpan 

develops in this soil; however, it can be broken by chiseling 

when the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and soil wetness. 

Dikes and channels that have outlets to bypass floodwater 

can be used to protect buildings from 

flooding. Wetness can be reduced by installing drain tile 

around footings. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Plants selected for 

use as ground cover should be alkali tolerant. 

The main limitation for septic tank absorption fields is 

wetness. 

This map unit is in capability subclass Illw, irrigated. 

92-Outlook silt loam. This very deep, artificially drained 

soil is on flood plains. It formed in alluvium. Slope is 0 to 3 

percent. The native vegetation is alkali-tolerant grasses and 

shrubs. Elevation is 650 to 2,000 feet. The average annual 

precipitation is 6 to 12 inches, the average annual air 

temperature is 51 degrees F, and the average frost-free 

season is 130 to 160 days. 

Typically, the surface layer is very dark brown, very dark 

grayish brown and dark grayish brown silt loam about 8 

inches thick and has yellowish brown or dark yellowish brown 

mottles. It is strongly alkaline. The subsoil is grayish brown, 

mottled silt loam about 10 inches thick. The substratum to a 

depth of 60 inches or more is dark brown silt loam. The 

subsoil and substratum are moderately alkaline. 

Included in this unit are small areas of Umapine and 

Sinloc soils and areas of Outlook soils that have not been 

artificially drained. 

Permeability of this Outlook soil is moderate. Available 

water capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 24 to 48 

inches. Runoff is ponded, and the hazard of water erosion is 

slight. This unit is partially protected from flooding, and the 

hazard of flooding is rare. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. Where the soil is this unit is drained, leached, 

and irrigated, the main crops are asparagus, corn, grain, hops, 

and mint. Grasses and legumes are grown for hay, pasture, 

and seed. Deep-rooted crops are suited to areas where the 

drainage is adequate or where a drainage system has been 

installed and is adequately maintained. 

The main limitations for irrigated crops are the hazard of 

water erosion and the high content of alkali. Dikes can be 

used to divert floodwater. Reclamation may require the 

addition of such amendments as gypsum, sulfur, or ferric 

sulfate to facilitate leaching. 

Furrow, corrugation, and sprinkler irrigation systems 

are suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. Use of sprinkler 

irrigation systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. If 

surface irrigation systems are used, the risk of erosion can 

be minimized by keeping runs short. Cultivation prior to 

irrigation improves the water infiltration rate; however, the 

fine soil particles dislodged during cultivation are highly 

susceptible to water erosion. This makes the initial period of 

irrigation extremely 
critical. The water application rate should be reduced 

accordingly to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from overirrigation, applications of irrigation 

water should also be adjusted to the available water capacity 

and the crop needs. 

Proper timing of minimum tillage and return of crop 

residue to the soil reduce compaction, help to maintain or 

improve the organic matter content, help to maintain tilth, 

and improve the water infiltration rate. Using vegetated filter 

strips at the end of rows or using sediment ponds, or both, 

reduces the volume of sediment in the tailwater. A plowpan 

develops in the soil in this unit; however, it can be broken by 

chiseling and subsoiling when the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and soil wetness. 

Dikes and channels that have outlets to bypass floodwater 

can be used to protect buildings and onsite sewage disposal 

systems from flooding. Wetness can be reduced by installing 

drain tile around footings. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Plants selected for 

ground cover need to be alkali tolerant. 

The main limitation for septic tank absorption fields is 

wetness. 

This map unit is in capability subclass Illw, irrigated. 

93-Pits. This unit consists primarily of gravel pits, 

areas used for sanitary landfills, and areas used as a 

source of clay. 

Most of the gravel pits are in areas of Weirman soils 

along the Yakima and Naches Rivers. These pits are mainly 

used as a source of material for roadfill and for surfacing 

roads and as a source of sand and gravel for use in 

concrete. Some gravel pits are in areas of Ashue and 

Scooteney soils and in areas of Harwood, Burke, and Wiehl 

soils on uplands. The Harwood and Burke soils, along with 

included areas of Gorst and Scoon soils, have a hardpan 

that contains gravel. The hardpan can be ripped and the 

material used as roadfill and for surfacing roads. 

This map unit is in capability subclass Vllls, 

nonirrigated. 

94-Prosser silt loam, 0 to 15 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed 

in loess and alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 300 to 1,150 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 160 to 180 days. 

Typically, the surface layer is brown silt loam about 4 

inches thick. The subsoil is pale brown silt loam about 10 

inches thick. The substratum is pale brown and light 

gray silt loam about 19 inches thick. Basalt is at a depth of 

about 33 inches. Depth to basalt ranges from 20 to 40 

inches. 

Included in this unit are areas of Mikkalo, Shano, and 

Starbuck soils. 

Permeability of this Prosser soil is moderate. Available 

water capacity is moderately high. Effective rooting depth is 

20 to 40 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for nonirrigated crops, as rangeland, 

and for wildlife habitat. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, and stripcropping. Seeding on the 

contour or across the slope slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation on this unit is mainly 

bluebunch wheatgrass, Sandberg bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. Areas 

that are heavily infested with undesirable vegetation can be 

improved by such methods as railing, chaining, beating, 

chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass lVe, 

nonirrigated. 

95-Quincy loamy fine sand, 0 to 10 percent slopes. 

This very deep, somewhat excessively drained soil is on 

terraces. It formed in eolian sand. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 650 to 

1,100 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 49 

degrees F, and the frost-free season is 135 to 180 days. 

Typically, the surface layer is grayish brown loamy fine 

sand about 20 inches thick. The underlying material to a 

depth of 60 inches or more is grayish brown medium sand. 

Included in this unit are small areas of Esquatzel, 

Warden, and Hezel soils and areas of Quincy soils that 

have the slopes of more than 10 percent. Also included 

are areas of alkali-affected soils that are somewhat poorly 

drained and soils that are underlain by basalt, 
gravel, or lacustrine sediment at a depth of 40 inches or 

more. 

Permeability of this Quincy soil is rapid. Available water 

capacity is low. Effective rooting depth is 60 inches or more. 

Runoff is very slow, and hazard of water erosion is slight. 

The hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain, potatoes, corn, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are rapid 

permeability, low available water capacity, steepness of 

slope, and the hazard of soil blowing. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water. Because this soil is droughty, frequent, light 

applications of irrigation water are needed. To avoid leaching 

of plant nutrients and loss of water, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. 

This unit should be protected with a cover crop during 

periods when it is susceptible to soil blowing, and it should 

be protected by crop residue until crops are well 

established in spring. To provide adequate cover in winter, 

fall grain, hay, or pasture should be seeded late in August or 

early in September. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation and maintaining crop 

residue on the surface reduce erosion. Use of straw, 

manure, or other waste material as a mulch reduces soil 

blowing, helps to maintain or improve the organic matter 

content, and conserves moisture. Seedbeds should be 

prepared when irrigation water is available to keep the soil 

surface moist. Vegetative barriers and shelterbelts can be 

used to control soil blowing. 

This unit is well suited to homesite development. Soil 

blowing can be a problem on large construction sites; 

therefore, these sites should be disturbed as little as 

possible. Cutbanks are not stable and subject to caving in. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage. 

This map unit is in capability subclass IVe, irrigated.

96-Renslow silt loam, 5 to 15 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 2,500 to 2,800. The average annual 

precipitation is 10 to 13 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is grayish brown and 

brown silt loam about 23 inches thick. The substratum to 

a depth of 60 inches or more is pale brown silt loam. In 

some areas basalt is at a depth of more than 40 inches. 

Included in this unit are areas of Starbuck, Mikkalo, 

and Willis soils and areas of Renslow soils that have 

slopes of less than 5 percent. 

Permeability of this Renslow soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are the low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, a 

cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, using terraces, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and Sandberg bluegrass. If the 

range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass and Idaho fescue 

decreases and the proportion of less preferred forage 

plants such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as railing, 

chaining, beating, plowing, chemical treatment, and 

prescribed burning. Range seeding is a suitable practice if 

the range vegetation is in poor condition. The unit should 

be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation is steepness of slope. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

If this unit is used for septic tank absorption fields, 

steepness of slope can cause lateral seepage and surfacing 

of effluent in downslope areas. Lateral seepage can be 

reduced by installing absorption lines on the contour or 

across the slope. 

This map unit is in capability subclass Ille, nonirrigated. 

97-Renslow silt loam, basalt substratum, 0 to 5 

percent slopes. This deep, well drained soil is on uplands. 

It formed in loess. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 2,500 to 2,800 feet. The 

average annual precipitation is 10 to 13 inches, the 

average annual air temperature is about 49 degrees F, and 

the average frost-free season is 130 to 150 days. 
Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is grayish brown and 

brown silt loam about 23 inches thick. The substratum is pale 

brown silt loam about 14 inches thick. Basalt is at a depth 

of about 44 inches. Depth to basalt ranges from 40 to 60 

inches. In some areas basalt is at a depth of more than 60 

inches. 

Included in this unit are areas of Mikkalo, Rock Creek, 

Starbuck, and Ritzville soils. 

Permeability of this Renslow soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 60 

inches. Runoff is slow, and the hazard of water erosion is 

slight. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are the low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, a 

cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, shaping and seeding 

waterways to perennial grass, using terraces and 

diversions, and stripcropping. Seeding on the contour or 

across the slope slows runoff and reduces erosion when the 

snow melts rapidly while the soil is still frozen. Drop 

structures are needed in a few places to stabilize the flow of 

runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and Sandberg bluegrass. If the 

range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass and Idaho fescue 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. This unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation for homesites is the moderate depth to bedrock, 

which hinders excavation. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

If this unit is used for septic tank absorption fields, the 

moderate depth to bedrock limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. In areas where the bedrock is 

fractured, contamination of ground water by unfiltered 

effluent is possible. 

This map unit is in capability subclass Ille, nonirrigated. 

98-Renslow silt loan, basalt substratum, 5 to 15 

percent slopes. This deep, well drained soil is on 

uplands. It formed in loess. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 2,500 to 2,800 feet. 

The average annual precipitation is 10 to 13 inches, the 

average annual air temperature is about 49 degrees F, and 

the average frost-free season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam about 

7 inches thick. The subsoil is grayish brown and brown silt 

loam about 23 inches thick. The substratum is pale brown silt 

loam about 14 inches thick. Basalt is at a depth of 44 inches. 

Depth to basalt ranges from 40 to 60 inches. In some areas 

basalt is at a depth of more than 60 inches. 

Included in this unit are areas of Mikkalo, Ritzville, Rock 

Creek, Starbuck, and Willis soils. 

Permeability of this Renslow soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 60 

inches. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain early, 

stubble mulching, using terraces and diversions, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial grass.

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and Sandberg bluegrass. If 

the range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass and Idaho fescue 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in poor 

condition. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitations are moderate depth to bedrock and steepness of 

slope. The bedrock hinders excavation. Dustiness can be a 

problem during construction on large building sites; therefore, 

these sites should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

moderate depth to bedrock and steepness of slope. The 

moderate depth to bedrock limits the capacity of the 

absorption fields. Slope can cause lateral seepage and 
surfacing of effluent in downslope areas. Absorption lines 

should be placed on the contour or across the slope. 

Where the bedrock is fractured, contamination of ground 

water by unfiltered effluent is possible. 

This map unit is in capability subclass Ille, nonirrigated. 

99-Ritzville silt loam, 2 to 5 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,500 feet. The average 

annual precipitation is 9 to 12 inches, the average annual 

air temperature is about 49 degrees F, and the average 

frost-free season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam about 

7 inches thick. The subsoil is brown or pale brown silt loam 

about 30 inches thick. The substratum to a depth of 60 

inches or more is light yellowish brown and pale brown silt 

loam. In some areas basalt, a hardpan, or old alluvium is at 

a depth of more than 40 inches. 

Included in this unit are small areas of Mikkalo, Selah, 

Willis, Harwood, Esquatzel, and Tieton soils and areas 

of Ritzville soils that have slopes of less than 2 percent. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is slow, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated and nonirrigated field and 

orchard crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are asparagus, 

corn, grain, grapes, hops, mint, peas, and tree fruit. Grasses 

and legumes are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of water 

erosion. Furrow, corrugation, drip, and sprinkler irrigation 

systems are suited to the soil in this unit. The type of system 

used depends on the kind of crop grown. If furrow or 

corrugation systems are used, runs should be on the contour 

or across the slope. The risk of erosion can be minimized 

by keeping runs short. Use of sprinkler or drip irrigation 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water 

infiltration rate; however, the fine soil particles dislodged 

during cultivation are highly susceptible to water 

erosion. This makes the initial period of irrigation extremely 

critical. The water application rate should be reduced 

accordingly to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from over irrigation, applications of irrigation 

water should also be adjusted to the available water capacity 

and the crop needs. Pipe, ditch lining, or drop structures 

should be installed in irrigation ditches to facilitate irrigation 

and prevent excessive ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Growing mint in meadows rather than in rows 

greatly reduces water erosion. A plowpan develops in the 

soil in this unit; however, it can be broken by chiseling or 

subsoiling when the soil is dry. Using vegetated filter 

strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by shaping waterways and 

seeding them to perennial grass. Seeding on the contour or 

across the slope slows runoff and reduces erosion when the 

snow melts rapidly while the soil is still frozen. Drop 

structures are needed in a few places to stabilize the flow of 

runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is well suited to homesite development. 

Dustiness can be a problem during construction on large 

building sites. Therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclasses Ile, irrigated 

and Ille, nonirrigated. 

100-Ritzville silt loam, 5 to 8 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,500 feet. The average 

annual precipitation is 9 to 12 inches, the average annual 

air temperature is about 49 degrees F, and the average 

frost-free season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is brown or pale brown silt 

loam about 30 inches thick. The substratum to a depth of 60 

inches or more is light yellowish brown and pale brown silt 

loam. In some areas basalt, a hardpan, or old alluvium is at 

a depth of more than 40 inches. 
Included in this unit are small areas of Selah, Willis, 

Harwood, and Tieton soils. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field and orchard crops 

and as rangeland, wildlife habitat, and homesites. The main 

irrigated crops are corn, grain, grapes, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs.

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue on 

the surface reduce water erosion. Cover crops are needed in 

orchards and vineyards to reduce erosion. A plowpan 

develops in the soil in this unit; however, it can be broken by 

chiseling or subsoiling when the soil is dry. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. This unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is well suited to homesite development. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

This map unit is in capability subclass IIIe, 

irrigated and nonirrigated. 

101-Ritzville silt loam, 8 to 15 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,500 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam about 

7 inches thick. T he subsoil is brown or pale brown silt loam 

about 30 inches thick. The substratum to a depth of 60 

inches or more is light yellowish brown and pale brown silt 

loam. In some areas basalt, a hardpan, or old alluvium is at a 

depth of more than 40 inches. 

Included in this unit are areas of Selah, Willis, Harwood, 

and Tieton soils. areas of Rock outcrop, and areas of 

Ritzville soils that have slopes of less than 8 percent. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grasses, 

legumes, grapes, and tree fruit. A cover crop is grown in 

orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to. the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Tillage should be across the slope or on the contour. Using 

a cropping system that includes close-growing, high-residue 

crops in the rotation and maintaining crop residue on the 

surface reduce water erosion. Growing annual or perennial 

cover crops reduces erosion in orchards and vineyards. A 

plowpan develops in the soil in this unit; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 
The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, using terraces, and stripcropping. 

Seeding on the contour or across the slope slows runoff 

and reduces erosion when the snow melts rapidly while the 

soil is still frozen. Waterways should be shaped and seeded 

to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and 

big sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation is steepness of slope. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

steepness of slope, which can cause lateral seepage and 

surfacing of effluent in downslope areas. Absorption lines 

should be installed on the contour or across the slope. 

This map unit is in capability subclasses IVe, irrigated, and 

Ille, nonirrigated. 

102-Ritzville silt loam, 15 to 30 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,500 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam about 

7 inches thick. The subsoil is brown or pale brown silt loam 

about 30 inches thick. The substratum to a depth of 60 

inches or more is light yellowish brown and pale brown silt 

loam. In some areas basalt, a hardpan, or old alluvium is at a 

depth of more than 40 inches. 

Included in this unit are small areas of Selah, Willis, 

Harwood, and Tieton soils. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grasses, 

legumes, grapes, and tree fruit (fig. 4). A cover crop is 

grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to ;

Irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs.

Use of minimum tillage and return of crop residue to the 

soil help to maintain the organic matter content, help to 

maintain tilth, and improve the water infiltration rate. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation reduces water erosion. Growing 

perennial cover in orchards and vineyards reduces erosion. A 

plowpan develops in the soil in this unit; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, using terraces, and 

divided-slope farming. Seeding on the contour or across 

the slope slows runoff and reduces erosion when the 

snow melts rapidly while the soil is still frozen. Drop 

structures are needed in places to control the flow of 

runoff in waterways. Waterways should be shaped and 

seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and 

big sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable shrubs can 

be improved by such methods as railing, chaining, beating, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is steepness of slope. Dustiness can 
Figure 4.-New fruit trees on terraces of Ritzville silt loam, 15 to 30 percent slopes. 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is 

steepness of slope. Slope can cause lateral seepage and 

surfacing of effluent in downslope areas. Lateral seepage 

can be reduced by installing absorption lines on the contour 

or across the slope. 

This map unit is in capability subclass IVe, 

irrigated and nonirrigated. 

103-Ritzville silt loam, 30 to 60 percent slopes. This 

very deep, well drained soil is on uplands. It formed in loess. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,200 to 2,500 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average 

frost-free season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is brown or pale brown silt 

loam about 30 inches thick. The substratum to a depth of 

60 inches or more is light yellowish brown and pale brown 

silt loam. In some areas the surface layer is calcareous. 

Included in this unit are Mikkalo, Starbuck, Willis, and 

Kiona soils. Included areas make up about 15 percent of the 

total acreage. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is very rapid, and the hazard of water 

erosion is very high. 

This unit is used as rangeland and for wildlife habitat. 

The potential vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and big 

sagebrush. If the range is overgrazed the proportion of 

preferred forage plants such as bluebunch wheatgrass 
and Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. Steepness of slope limits access by 

livestock and promotes overgrazing of the less sloping 

areas. Proper location of salt licks, stock water tanks, and 

fences promotes uniform distribution of grazing. 

Areas that are heavily infested with undesirable 

vegetation can be improved by chemical treatment and 

prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition. Use of equipment 

may be difficult in the more steeply sloping areas. The unit 

should be seeded in fall using aerial methods. Adapted 

grasses and legumes should be seeded. 

This map unit is in capability subclass VIle, 

nonirrigated. 

104-Ritzville silt loam, basalt substratum, 0 to 5 

percent slopes. This deep, well drained soil is on uplands. 

It formed in loess. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 1,200 to 2,500 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is brown or pale brown silt 

loam about 30 inches thick. The substratum is light yellowish 

brown silt loam about 8 inches thick. Basalt is at a depth of 

about 45 inches. Depth to bedrock ranges from 40 to 60 

inches. In some areas a lime- and silica-cemented hardpan 

is at a depth of more than 40 inches, and in some areas 

depth to basalt is 60 inches or more. 

Included in this unit are small areas of Mikkalo, Willis, 

and Esquatzel soils. Included areas make up about 15 

percent of the total acreage. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 60 

inches. Runoff is slow, and the hazard of water erosion is 

slight. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall 

grain early, stubble mulching, and shaping waterways 

and seeding them to perennial grass. Seeding on the 

contour or across the slope slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Drop structures are needed in a few places to 

stabilize the flow of runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and 

big sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation is moderate depth to rock, which hinders 

excavation. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

moderate depth to rock, which limits the capacity of the 

absorption fields. The use of long absorption lines helps to 

compensate for this limitation. Where the bedrock is 

fractured, contamination of ground water by unfiltered 

effluent is possible. 

This map unit is in capability subclass Ille, nonirrigated. 

105-Ritzville silt loam, basalt substratum, 5 to 15 

percent slopes. This deep, well drained soil is on uplands. 

It formed in loess. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 1,200 to 2,500 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 130 to,

 150 days. 

Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is brown or pale brown silt 

loam about 30 inches thick. The substratum is light 

yellowish brown silt loam about 8 inches thick. Basalt is at a 

depth of about 45 inches. Depth to basalt ranges from 40 to 

60 inches. In some areas a lime- and silica-cemented 

hardpan is at a depth of more than 40 inches, and in some 

areas depth to basalt is 60 inches or more. 

Included in this unit are areas of Mikkalo and Willis 

soils. Included areas make up about 15 percent of the 

total acreage. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 50 

inches. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

These main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by 

seeding fall grain early, stubble mulching, using terraces, 

and stripcropping. Seeding on the contour or across the 

slope slows runoff and reduces 
erosion when the snow melts rapidly while the soil is still 

frozen. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and 

big sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbit brush 

increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitations are steepness of slope and depth to rock, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

depth to rock and steepness of slope. The depth to rock 

restricts the capacity of the absorption fields. Use of long 

absorption lines helps to compensate for this limitation. 

Where the bedrock is fractured, contamination of ground 

water by unfiltered effluent is possible. Slope can cause 

lateral seepage and surfacing of effluent in downslope 

areas. Lateral seepage can be reduced by installing 

absorption lines on the contour or across the slope. 

This map unit is in capability subclass Ille, nonirrigated. 

106-Ritzville silt loam, basalt substratum, 15 to 30 

percent slopes. This deep, well drained soil is on uplands. It 

formed in loess. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 1,200 to 2,500 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 130 to 150 days. 

Typically, the surface layer is grayish brown silt loam 

about 7 inches thick. The subsoil is brown or pale brown silt 

loam about 30 inches thick. The substratum is light 

yellowish brown silt loam about 8 inches thick. Basalt is at a 

depth of about 45 inches. Depth to basalt ranges from 40 to 

60 inches. In some areas a lime- and silica-cemented 

hardpan is at a depth of more than 40 inches, and in some 

areas depth to basalt is 60 inches or more. 

Included in this unit are areas of Mikkalo and Willis 

soils. Included areas make up about 15 percent of the 

total acreage. 

Permeability of this Ritzville soil is moderate. Available 

water capacity is high. Effective rooting depth is 40 to 60 

inches. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, divided-slope farming, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitation is steepness of slope. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is 

steepness of slope, which can cause lateral seepage and 

surfacing of effluent in downslope areas. Lateral seepage 

can be reduced by installing absorption lines on the contour 

or across the slope. Where the underlying basalt is 

fractured, contamination of ground water by unfiltered 

effluent is possible. 

This map unit is in capability subclass IVe, 

nonirrigated. 

107-Ritzville Variant silt loam, 5 to 15 percent 

slopes. This very deep, well drained soil is on terraces. It 

formed in loess overlying cobbly or gravelly alluvium. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,200 to 1,800 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 150 days. 

Typically, the surface layer is brown silt loam about 7 

inches thick. The subsoil is pale brown silt loam about 11 

inches thick. The upper part of the substratum is pale brown 

gravelly silt loam about 10 inches thick, and the 
lower part to a depth of 60 inches or more is pale brown 

and light gray very cobbly loam. 

Included in this unit are areas of Ritzville and Willis 

soils. 

Permeability of this Ritzville Variant soil is moderate. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain early, 

stubble mulching, using terraces, and stripcropping. Seeding 

on the contour or across the slope slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation for homesites is steepness of slope. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, 

slope can cause lateral seepage and surfacing of 

effluent in downslope areas. Lateral seepage can be 

avoided by installing absorption lines on the contour. 

This map unit is in capability subclass Ille, nonirrigated. 

108-Ritzville Variant cobbly silt loam, 5 to 15 

percent slopes. This very deep, well drained soil is on 

terraces. It formed in loess overlying cobbly alluvium. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,200 to 1,800 feet. The average annual 

precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 150 days. 

Typically, the surface layer is brown cobbly silt loam 

about 7 inches thick. The subsoil is pale brown cobbly 

silt loam about 11 inches thick. The upper part of the 

substratum is pale brown gravelly silt loam about 10 inches 

thick, and the lower part to a depth of 60 inches or more is 

pale brown and light gray very cobbly loam. 

Included in this unit are areas of Ritzville, Willis, and 

Kiona soils. 

Permeability of this Ritzville Variant soil is moderate. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as rangeland, wildlife habitat, and 

homesites. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, Sandberg bluegrass, and 

big sagebrush. If the range is overgrazed, the 

proportion of preferred forage plants such as 

bluebunch wheatgrass and Idaho fescue decreases 

and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as chaining, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Removal of 

stones might be necessary. Adapted grasses and legumes 

should be seeded. 

This unit is suited to homesite development. The main 

limitation for homesites is steepness of slope. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, slope 

can cause lateral seepage and surfacing of effluent in 

downslope areas. Lateral seepage can be reduced by 

installing absorption lines on the contour or across the 

slope. 

This map unit is in capability subclass IVe, 

nonirrigated. 

109-Rock Creek very stony silt loam, 0 to 30 

percent slopes. This shallow, well drained soil is on 

plateaus and ridgetops. It formed in loess and in residuum 

derived from basalt. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 1,200 to 3,200 feet. 

The average annual precipitation is 12 to 16 inches, the 

average annual air temperature is about 48 degrees F, and 

the average frost-free season is 120 to 170 days. 

Typically, the surface layer is grayish brown very stony silt 

loam about 2 inches thick. The subsoil is brown very cobbly 

clay about 8 inches thick. Basalt is at a depth of about 10 

inches. Depth to basalt ranges from 8 to 15 inches. In some 

areas the surface layer is stony. 

Included in this unit are areas of McDaniel, Gorst, 

Clint, Taneum, and Simcoe soils and areas of Rock 

outcrop. 
Permeability of this Rock Creek soil is moderately slow. 

Available water capacity is low. Effective rooting depth is 

8 to 15 inches. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as rangeland, wildlife habitat, and 

homesites. 

The potential native vegetation is mainly Sandberg 

bluegrass, stiff sagebrush, and eriogonum. The main 

limitations for the production of forage are depth to rock 

and low available water capacity. If the range is overgrazed, 

the proportion of preferred forage plants such as stiff 

sagebrush and Sandberg bluegrass decreases and the 

proportion of less preferred forage plants such as forbs and 

annual grasses increases. Areas that are heavily infested 

with undesirable vegetation can be improved by chemical 

treatment. 

This unit is poorly suited to homesite development. The 

main limitations are shallow depth to bedrock, large stones, 

and steepness of slope. Bedrock hinders excavation. 

Removal of the large stones is needed for best results when 

landscaping, particularly in areas used for lawns. 

The main limitations for septic tank absorption fields are 

shallow depth to bedrock, steepness of slope, and large 

stones. The shallow depth to bedrock limits the capacity of 

the absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Absorption lines should be 

placed on the contour or across the slope. The large stones 

can interfere with the location of these lines. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

110-Rock Creek-Clint-Simcoe complex, 0 to 45 

percent slopes. This map unit is on uplands. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 2,000 to 3,300 feet. The average annual 

precipitation is 10 to 18 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 120 to 135 days. 

This unit is about 40 percent Rock Creek very stony silt 

loam, about 20 percent Clint very stony loam, and about 

20 percent Simcoe silt loam. The components of this unit 

are so intricately intermingled that it was not practical to 

map them separately at the scale used. 

Included in this unit are areas of Harwood soils that 

have slopes of less than 25 percent. Also included are 

areas of McDaniel and Taneum soils. Included areas make 

up about 20 percent of the total acreage. 

The Rock Creek soil is very shallow and shallow and is 

well drained. It formed in loess and in residuum derived from 

basalt. Typically, the surface layer is grayish brown very 

stony silt loam about 2 inches thick. The subsoil is brown 

very cobbly clay about 8 inches thick. Basalt is at a depth of 

about 10 inches. Depth to bedrock ranges from 8 to 15 

inches. In some areas the surface layer is stony. 

Permeability of the Rock Creek soil is moderately 

slow. Available water capacity is low. Effective rooting 

depth is 8 to 15 inches. Runoff is rapid, and the hazard 

of water erosion is high. 

The Clint soil is moderately deep and well drained. It 

formed in loess and in residuum derived from basalt. 

Typically, the upper part of the surface layer is reddish 

brown very stony loam about 6 inches thick, and the lower 

part is reddish brown gravelly loam about 4 inches thick. 

The subsoil is reddish brown very gravelly loam about 9 

inches thick. The substratum is dark brown extremely 

gravelly loam about 9 inches thick. Fractured basalt is at a 

depth of about 28 inches. Depth to basalt ranges from 20 to 

40 inches. In some areas the surface layer is stony. 

Permeability of the Clint soil is moderate. Available water 

capacity is low. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 

The Simcoe soil is moderately deep and well drained. It 

formed in loess and in residuum derived from basalt. 

Typically, the surface layer is brown silt loam about 3 inches 

thick. The subsoil is brown silt loam about 24 inches thick. 

Basalt is at a depth of about 27 inches. Depth to basalt 

ranges from 20 to 40 inches. 

Permeability of the Simcoe soil is moderately slow. 

Available water capacity is moderate. Effective rooting depth 

is 20 to 40 inches. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation of the Rock Creek soil is 

mainly stiff sagebrush, Sandberg bluegrass, and eriogonum. 

If the range is overgrazed, the proportion of preferred forage 

plants such as stiff sagebrush and Sandberg bluegrass 

decreases and the proportion of less preferred forage plants 

such as forbs and annual grasses increases. 

The potential native vegetation of the Clint soil is mainly 

bluebunch wheatgrass, Idaho fescue, and Sandberg 

bluegrass. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. 

The potential native vegetation of the Simcoe soil is mainly 

bluebunch wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such as 

bluebunch wheatgrass decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. 

The main limitations for the production of forage is the very 

stony surface layer of the Rock Creek and Clint soils. Areas 

of the Clint and Simcoe soils that are heavily infested with 

undesirable vegetation can be improved with such methods 

as chaining, chemical treatment, and prescribed burning. 

Care should be taken during brush control not to disturb the 

very shallow Rock Creek soil. 
Range seeding on the Rock Creek soil is not feasible 

because of the very shallow and shallow depth to rock and 

low available water capacity. Seeding is difficult because of 

the stoniness of the Clint soil and the predominance of the 

Rock Creek soil between mounds of the Clint and Simcoe 

soils. The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

111-Roza clay loam, 5 to 8 percent slopes. This very 

deep, well drained soil is on uplands. It formed in material 

derived from fine-textured sediment. The native vegetation 

is mainly grasses, forbs, and shrubs. Elevation is 1,300 to 

1,800 feet. The average annual precipitation is 8 to 12 

inches, the average annual air tpmnnrptllro is nhniit rl 

rlenrpcc F nnri tha frost-free season is 135 to 150 days. 

Typically, the surface layer is grayish brown clay loam 

about 2 inches thick. The upper part of the subsoil is grayish 

brown clay loam about 9 inches thick, and the lower part is 

light brownish gray silty clay about 8 inches thick. The 

substratum to a depth of 60 inches or more is light brownish 

gray, pale brown, and light gray silty clay, silty clay loam, 

and clay loam. Vertical cracks 1/2- to 1-inch wide extend 

from the surface to a depth of about 19 inches. In some 

areas the soil is underlain by sandstone, and in some areas 

the soil has an intermittent hardpan. 

Included in this unit are areas of Selah, Cowiche, and 

Cleman soils. Included areas make up about 25 percent of 

the total acreage. 

Permeability of this Roza soil is slow. Available water 

capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain and tree fruit. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are the slow 

permeability and steepness of slope. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. As the moisture content of the soil increases, the 

clay in this soil expands and the water infiltration rate is 

reduced. Irrigation water, therefore, should be applied at a 

slow rate over a long period of time to insure that the root 

zone is properly wetted. This also helps to control erosion 

and the production of sediment. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should also be adjusted to the available water 

capacity and the crop needs. 

When the soil in this unit is excessively moist, operation of 

equipment increases the possibility of soil compaction, 

development of a plowpan, and formation of large clods at 

the surface. If the soil is compacted, it can be chiseled or 

subsoiled when dry. Seedbed preparation and seeding 

should be-done when the soil is dry. Applications of irrigation 

water should follow if needed. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water erosion. 

Cover crops should be grown in orchards and vineyards to 

reduce erosion. 

This unit is poorly suited to homesite development. The 

main limitation is shrink-swell potential, which can damage 

footings and foundations. Properly designing foundations 

and footings and diverting runoff away from buildings. help 

to prevent structural damage. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is slow 

permeability. Use of sandy backfill for the trench and long 

absorption lines helps to compensate for this limitation. 

This map unit is in capability subclass Ille, irrigated. 

112-Roza clay loam, 8 to 15 percent slopes. This very 

deep, well drained soil is on uplands. It formed in material 

derived from fine-textured sediment. The native vegetation 

is mainly grasses, forbs, and shrubs. Elevation is 1,300 to 

1,800 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is about 135 

to 150 days. 

Typically, the surface layer is grayish brown clay loam 

about 2 inches thick. The upper part of the subsoil is grayish 

brown clay loam about 9 inches thick, and the lower part is 

light brownish gray silty clay about 8 inches thick. The 

substratum to a depth of 60 inches or more is light brownish 

gray, pale brown, and light gray silty clay, silty clay loam, 

and clay loam. Vertical cracks 1/2- to 1-inch wide extend 

from the surface to a depth of 19 inches. In some areas the 

soil is underlain by sandstone, and in some areas the soil 

has an intermittent hardpan. 

Included in this unit are areas of Selah, Cowiche, and 

Cleman soils and areas of Roza soils that have slopes of 

less than 8 percent. Included areas make up about 25 

percent of the total acreage. 

Permeability of this Roza soil is slow. Available water 

capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are grain and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope and slow permeability. Sprinkler and drip 
irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. As the moisture content of the soil increases, the 

clay in this soil expands and the water infiltration rate is 

reduced. Irrigation water, therefore, should be applied at a 

slow rate over a long period of time to insure that the root 

zone is properly wetted. This also helps to control erosion 

and the production of sediment. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should also be adjusted to the available 

water capacity and the crop needs. 

The soil in this unit should be cultivated when dry to 

reduce the possibility of soil compaction, development of a 

plowpan, and formation of large clods at the surface. If the 

soil is compacted, it can be chiseled or subsoiled when dry. 

Seedbed preparation and seeding should be done when the 

soil is dry. Applications of irrigation water should follow if 

needed. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water erosion. 

Cover crops can be grown in orchards and vineyards to 

reduce erosion. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Cusick bluegrass, and spiny hopsage. The unit 

has few limitations for the production of forage. If the range 

is overgrazed, the proportion of preferred forage plants 

such as bluebunch wheatgrass decreases and the 

proportion of less preferred forage plants such as big 

sagebrush and rubber rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed burning. 

Seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded just before the 

rains in fall using a drill. Because of the possibility of soil 

compaction and formation of large clods at the surface, the 

soil in this unit should be tilled when dry. Seedbed 

preparation and seeding can be done when the soil is dry. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is shrink-swell potential, which can damage 

footings or foundations. Properly designing 

foundations and footings and diverting runoff away from 

buildings help to prevent structural damage. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is slow 

permeability. Use of sandy backfill for the trench and long 

absorption lines help to compensate for this limitation. Slope 

can cause lateral seepage and surfacing of the effluent in 

downslope areas. Absorption lines should be placed on the 

contour or across the slope. 

This map unit is in capability subclass IVe, irrigated and 

nonirrigated. 

113-Roza clay loam, 15 to 30 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

material derived from fine-textured sediment. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

1,300 to 2,400 feet. The average annual precipitation is 8 to 

12 inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typically, the surface layer is grayish brown clay loam 

about 2 inches thick. The upper part of the subsoil is grayish 

brown clay loam about 9 inches thick, and the lower part is 

light brownish gray silty clay about 8 inches thick. The 

substratum to a depth of 60 inches or more is light brownish 

gray, pale brown, and light gray silty clay, silty clay loam, 

and clay loam. Vertical cracks 1/2 to 1- wide extend from 

the surface to a depth of about 19 inches. In some areas the 

soil is cobbly throughout, in some areas the soil is underlain 

by sandstone, and in some areas the soil has an intermittent 

hardpan. 

Included in this unit are areas of Selah, Cowiche, and 

Cleman soils. Included areas make up about 25 percent of 

the total acreage. 

Permeability of this Roza soil is slow. Available water 

capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crop is tree fruit. A cover crop is grown in 

orchards. Grasses and legumes are grown for hay, 

pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope and slow permeability. Sprinkler and drip irrigation 

systems are suited to the soil in this unit. The type of 

system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. As the moisture content of the soil increases, the 

clay in this soil expands and the water infiltration rate is 

reduced. Irrigation water, therefore, should be applied at a 

slow rate over a long period of time to insure that the root 

zone is properly wetted. This also helps to control erosion 

and the production of sediment. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity and the crop needs. 

When moist, the soil in this unit should not be cultivated 

because of the possibility of soil compaction, development 

of a plowpan, formation of large clods at the surface, and 

an extremely slippery soil condition. Where the soil is 

compacted, it can be chiseled or subsoiled when dry. 

Seedbed preparation and seeding 
should be done when the soil is dry. Applications of 

irrigation water should follow if needed. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water erosion. 

Cover crops can be grown in orchards and vineyards to 

reduce erosion. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Cusick bluegrass, and spiny hopsage. This unit 

has few limitations for the production of forage. If the range 

is overgrazed, the proportion of undesirable forage plants 

such as big sagebrush and rubber rabbitbrush increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved with such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. When moist, the soil in this unit should not 

be tilled because of the possibility of soil compaction and 

formation of large clods at the surface. Seedbed preparation 

and seeding should be done when the soil is dry. Adapted 

grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are shrink-swell potential and steepness of 

slope. Shrinking and swelling of the soil in this unit can 

damage footings and foundations. Properly designing 

foundations and footings and diverting runoff away from 

buildings help to prevent structural damage. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as possible.

The main limitations for septic tank absorption fields are 

steepness of slope and slow permeability. Use of sandy 

backfill for the trench and long absorption lines helps to 

compensate for the slow permeability. Slope can cause 

lateral seepage and surfacing of the effluent in downslope 

areas. 

This map unit is in capability subclass IVe, irrigated 

and nonirrigated. 

114-Roza clay loam, 30 to 60 percent slopes. This 

very deep, well drained soil is on uplands. It formed in finetextured sediment. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 1,300 to 2,400 

feet. The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 51 degrees F, and 

the average frost-free season is 135 to 150 days. 

Typically, the surface layer is grayish brown clay 

loam about 2 inches thick. The upper part of the subsoil is 

grayish brown clay loam about 9 inches thick, and the lower 

part is light brownish gray silty clay about 8 inches thick. 

The substratum to a depth of 60 inches or more is light 

brownish gray silty clay and silty clay loam. Vertical cracks 1 

/2- to 1 -inch wide extend from the surface to a depth of 

about 19 inches. In some areas the soil is cobbly 

throughout, in some areas the soil is underlain by 

sandstone at a depth of 40 to 60 inches, and in some 

areas the soil has an intermittent hardpan. 

Included in this unit are areas of Taneum soils, areas of 

Roza soils that have slopes of less than 30 percent, and 

areas of eroded soils. 

Permeability of this Roza soil is slow. Available water 

capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is very rapid, and the hazard of water erosion 

is very high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Cusick bluegrass, and spiny hopsage. The 

main limitation for the production of forage is steepness of 

slope, which limits access and promotes overgrazing of the 

less sloping areas. The distribution of grazing in the steeply 

sloping areas of this unit can be improved by proper location 

of salt licks, stock watering facilities, and management 

fences. 

If the range is overgrazed, the proportion of preferred 

forage plants such as bluebunch wheatgrass decreases and 

the proportion of less preferred forage plants such as big 

sagebrush and rubber rabbitbrush increases. Areas that are 

heavily infested with undesirable vegetation can be 

improved with such methods as chemical treatment and 

prescribed burning. Aerial range seeding is a suitable 

practice if the range vegetation is in poor condition. Adapted 

grasses and legumes should be seeded. 

This map unit is in capability subclass VIle, 

nonirrigated. 

115-Rubble land-Rock outcrop association. This map 

unit is in canyons and on steep mountainsides and 

escarpments. The native vegetation is scattered grasses and 

shrubs. Elevation is 2,400 to 7,000 feet. The average annual 

precipitation is 18 to 50 inches, the average annual air 

temperature is about 43 degrees F, and the average frostfree season is 95 to 130 days. 

This unit is about 70 percent Rubble land and 15 percent 

Rock outcrop. The components of this unit are so intricately 

intermingled that it was not practical to map them separately 

at the scale used. 

Included in this unit are about 10 percent Sapkin and 

Bocker soils and about 5 percent Jumpe, Sutkin, and 

Naxing soils. Also included, on south-facing mountainsides 

between Darland Mountain and Klickitat Meadows, are 

areas that are about 70 percent Rock outcrop. 

Rubble land consists of areas of cobbles and boulders on 

mountain toe slopes and areas of stone strips on steep 

mountainsides. It commonly is below areas of Rock outcrop 

and is mainly free of vegetation. 

Rock outcrop is areas of exposed basalt. 

This unit is used for wildlife habitat. 

Most areas of the unit support mosses and lichens. 

Grazing is limited by low production and by the difficulty 

of animal movement. Production of timber is very limited. 
Timber harvesting is restricted by stones and cobbles. 

Rubble land is a good source of material for road ballast. 

This map unit is in capability subclass VIlls, 

nonirrigated. 

116-Sapkin very stony loam, 10 to 45 percent 

slopes. This moderately deep, well drained soil is on uplands 

and mountainsides. It formed in colluvium and residuum that 

are derived from basalt and contain small amounts of loess. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 3,200 to 5,000 feet. The average annual 

precipitation is 18 to 35 inches, the average annual air 

temperature is about 43 degrees F, and the average frostfree season is 95 to 130 days. 

Typically, the upper part of the surface layer is dark 

grayish brown very stony loam about 7 inches thick, and the 

lower part is brown loam about 8 inches thick. The upper 

part of the subsoil is brown cobbly loam about 12 inches 

thick, and the lower part is brown very cobbly loam and 

extremely cobbly clay loam about 8 inches thick. Basalt is at 

a depth of about 35 inches. Depth to basalt ranges from 20 

to 40 inches. 

Included in this unit are areas of Bocker, Jumpe, and 

Sutkin soils; areas of Rock outcrop and Rubble land; and 

small convex areas of Sapkin soils that have slopes of 45 to 

75 percent. Included areas make up about 10 percent of the 

total acreage. 

Permeability of this Sapkin soil is moderate. 

Available water capacity is low. Effective rooting depth is 

20 to 40 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly Idaho fescue, 

bluebunch wheatgrass, buckwheat, and threetip 

sagebrush. The production of forage is limited by the very 

stony surface layer. If the range is overgrazed, the proportion 

of preferred forage plants such as Idaho fescue and 

bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as threetip sagebrush 

and cheatgrass increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as 

chaining, railing, chemical treatment, and 

prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition. The unit should 

be seeded in fall using a drill. 

This unit is limited for livestock watering ponds and other 

water impoundments because of moderate depth to 

bedrock. Water tanks, springs, wells, and pipelines are more 

suitable for providing stock water. 

This map unit is in capability subclass 

VIIs, nonirrigated. 

117-Sapkin very stony loam, 45 to 75 percent 

slopes. This moderately deep, well drained soil is on 

uplands and mountainsides. It formed in colluvium and 

residuum that are derived dominantly from basalt and 

contain small amounts of loess. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 3,200 to 

5,000 feet. The average annual precipitation is 18 to 35 

inches, the average annual air temperature is about 43 

degrees F, and the average frost-free season is 95 to 130 

days. 

Typically, the upper part of the surface layer is dark 

grayish brown very stony loam about 7 inches thick. The 

lower part is brown loam about 8 inches thick. The upper 

part of the subsoil is brown cobbly loam about 12 inches 

thick, and the lower part is brown very cobbly loam and 

extremely cobbly clay loam about 8 inches thick. Basalt is at 

a depth of about 35 inches. Depth to basalt ranges from 20 

to 40 inches. 

Included in this unit are areas of Jumpe, Sutkin, and 

Bocker soils; areas of Rock outcrop and Rubble land; and 

small concave areas of Sapkin soils, on toe slopes and in 

convex areas on ridgetops, that have slopes of 10 to 45 

percent. Included areas make up about 15 percent of the 

total acreage. 

Permeability of this Sapkin soil is moderate. Available 

water capacity is low. Effective rooting depth is 20 to 40 

inches. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly Idaho fescue, 

bluebunch wheatgrass, and threetip sagebrush. The main 

limitation for the production of forage is the presence of large 

stones. If the range is overgrazed, the proportion of 

preferred forage plants such as Idaho fescue and bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as threetip sagebrush and cheatgrass 

increases. 

Steepness of slope promotes overgrazing of the less 

sloping areas. Proper location of salt licks, stock water tanks, 

and fences promote more uniform distribution of grazing. 

Brush control is largely limited to aerial application of 

chemicals or to prescribed burning because of steepness of 

slope and stoniness. Seeding is hindered by stones on the 

surface and steepness of slope. Adapted grasses and 

legumes should be seeded. 

This unit is limited for livestock watering ponds and other 

water impoundments because of moderate depth to bedrock. 

Water tanks, springs, wells, and pipelines are more effective 

means for providing stock water. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

118-Sapkin-Rubble land complex, 30 to 75 percent 

slopes. This map unit is on mountainsides. Slope is 

dominantly about 45 percent. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 2,800 

to 5,600 feet. The average annual precipitation is 18 to 35 

inches, the average annual air temperature is about 43 

degrees F, and the average frost-free season is 95 to 130 

days. 
This unit is about 60 percent Sapkin very stony loam and 

about 30 percent Rubble land. The components of this unit 

are so intricately intermingled that it was not practical to 

map them separately at the scale used. 

Included in this unit are areas of Sutkin and Bocker soils 

and areas of Rock outcrop. Included areas make up about 

10 percent of the total acreage. 

The Sapkin soil is moderately deep and well drained. It 

formed in residuum and colluvium derived dominantly 

from basalt and containing small amounts of loess. Typically, 

the upper part of the surface layer is dark grayish brown very 

stony loam about 7 inches thick. The lower part is brown 

loam about 8 inches thick. The upper part of the subsoil is 

brown cobbly loam about 12 inches thick, and the lower part 

is brown very cobbly loam and extremely cobbly clay loam 

about 8 inches thick. Basalt is at a depth of about 35 inches. 

Depth to basalt ranges from 20 to 40 inches. In some areas 

the subsoil is clay loam, and in some areas bedrock is at a 

depth of more than 40 inches. 

Permeability of the Sapkin soil is moderate. Available 

water capacity is low. Effective rooting depth is 20 to 40 

inches. Runoff is rapid, and the hazard of water erosion is 

high. 

Rubble land is areas of cobbles, stones, and boulders. It is 

mainly free of vegetation. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly Idaho fescue, 

bluebunch wheatgrass, and threetip sagebrush on the 

Sapkin soil. The main limitations for the production of forage 

are the presence of large stones and steepness of slope, 

which promotes overgrazing of the less sloping areas. 

Proper location of salt licks, stock water tanks, and fences 

promote more uniform distribution of grazing. If the 

range is overgrazed, the proportion of preferred forage plants 

such as Idaho fescue and bluebunch wheatgrass decreases 

and the proportion of less preferred forage plants such as 

threetip sagebrush and cheatgrass increases. 

Areas that are heavily infested with undesirable 

vegetation can be improved with such methods as chemical 

treatment and prescribed burning. Plant control is mainly 

limited to chemical application by air or to prescribed 

burning because of steepness of slope and stoniness. This 

unit should be seeded in fall. Adapted grasses and legumes 

should be seeded. 

This unit is limited for livestock watering ponds and other 

water impoundments because of moderate depth to 

basalt. Water tanks, springs, wells, and pipelines are 

more effective means for providing stock water. 

This map unit is in capability subclass 

VIIs, nonirrigated. 

119-Saydab cobbly loam, 0 to 5 percent slopes. This 

moderately deep, moderately well drained soil is on smooth 

mountaintops and broad ridgetops. It formed in colluvium 

and residuum derived from basalt and 

containing small amounts of loess. The native vegetation is 

mainly conifers and grasses. Elevation is 5,500 to 7,000 

feet. The average annual precipitation is 40 to 50 inches, 

the average annual air temperature is about 41 degrees F, 

and the average length of the growing season, at 28

degrees F, is 80 to 110 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 inch thick. The upper 

part of the surface layer is dark brown cobbly loam about 5 

inches thick, and the lower part is dark brown loam about 6 

inches thick. The subsoil is yellowish brown very cobbly 

loam about 16 inches thick. Basalt is at a depth of about 27 

inches. Depth to basalt ranges from 25 to 30 inches. 

Included in this unit are areas of Naxing and Darland 

soils, areas of Saydab soils that have slopes of more than 

15 percent, and areas of soils that have basalt at a depth of 

10 to 20 inches. Included areas make upabout 10 percent of 

the total acreage. 

Permeability of this Saydab soil is moderate. Available 

water capacity is low. Effective rooting depth is 25 to 30 

inches. Runoff is slow, and hazard of water erosion is slight. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Subalpine fir and western larch are the main woodland 

species on this unit. Among the trees of limited extent are 

whitebark pine, lodgepole pine, and Engelmann spruce. On 

the basis of a 50-year site curve, the mean site index is 49 

for western larch. Yield tables for normal, even-aged, 

unmanaged stands of western larch indicate that the mean 

annual increment at culmination (CMAI) for trees 0.6 inch in 

diameter and larger at 70 years of age is 61 cubic feet per 

acre. The mean annual increment for trees 7.6 inches in 

diameter and larger at 80 years of age is 30 cubic feet per

acre. On the basis of a 100-year site curve, the mean site 

index is 87 for lodgepole pine and 74 for subalpine fir. Yield 

tables for normal, even-aged, unmanaged stands of 

lodgepole pine at 100 years of age indicate that the mean 

annual increment at culmination is about 100 cubic feet per 

acre. However, the typical basal area of stands on this unit 

is about 60 percent that of normal stands, and the total yield 

is correspondingly lower. 

The main limitation for the harvesting of timber is 

snowpack, which hinders the use of equipment and limits 

access in winter. Unsurfaced roads and skid trails are soft 

when wet, and they may be impassable during spring runoff 

or in rainy periods. Logging roads require suitable surfacing 

for year-round use. Rock for road construction is not readily 

available on this unit. 

Seedling establishment is the main concern in the 

production of timber. If seed trees are present, natural 

reforestation of cutover areas by subalpine fir occurs 

periodically. Low soil temperatures, heavy snowpack, and 

the short growing season limit the even distribution of 

natural reforestation, especially on north-facing 
slopes. Because the rooting depth is restricted by 

underlying bedrock, trees are occasionally subject to 

windthrow. 

The common forest understory plants are elk sedge, 

pinegrass, vetch, yarrow, sagebrush, currant, and 

dwarf huckleberry. The crown density in the areas where 

the woodland site index was measured is 30 percent. This 

unit is well suited to grazing and browsing. Seeding to 

adapted grazable vegetation following logging or burning 

late in summer or in fall generally is most successful. 

This unit is limited for livestock watering ponds and other 

water impoundments because of moderate depth to 

bedrock. Spring developments, wells, or pipelines can be 

used to provide stock water. 

This map unit is in capability subclass Vle, 

nonirrigated. 

120-Scoon silt loam. 2 to 5 percent slopes. This well 

drained soil in on uplands. It is shallow over a lime- and 

silica-cemented hardpan. It formed in loess. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 800 to 1,400 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is light brownish gray silt loam 

about 6 inches thick. The subsoil is light brownish gray silt 

loam about 4 inches thick. The substratum is light brownish 

gray gravelly silt loam about 6 inches thick. A hardpan is at 

a depth of about 16 inches. Depth to the hardpan ranges 

from 10 to 20 inches. The hardpan commonly is underlain 

by basalt, but in some areas it is underlain by sand and 

gravel. In some areas the surface layer is very fine sandy 

loam. 

Included in this unit are small areas of Shano, Burke, 

Roza, and Starbuck soils, areas of Rock outcrop, and 

areas of Scoon soils that have slopes of less than 2 

percent. 

Permeability of this Scoon soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 10 to 20 inches. Runoff is 

slow, and the hazard of water erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are grain, mint, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are suited to 

the soil in this unit. The type of system used depends on 

the kind of crop grown. Use of these irrigation systems 

permits the even, controlled application of irrigation water, 

reduces runoff, and minimizes the risk of erosion. Shallow 

depth to the pan and steepness of slope make water 

management extremely important. To avoid loss of water 

and leaching 

of plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity and 

the crop needs. 

Using a cropping system that includes close-growing, highresidue crops and growing mint in meadows rather than in 

rows reduce water erosion. Perennial cover crops reduce 

erosion in orchards. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production of 

forage is limited by low available water capacity. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as chaining, railing, beating, chemical treatment, 

and prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition, but it is difficult 

because of low available water capacity. The unit should be 

seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites is the shallow depth to the 

hardpan, which hinders excavation. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, the 

shallow depth to the pan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclasses IVe, 

irrigated, and Vle, nonirrigated. 

121-Scoon silt loam, 5 to 8 percent slopes. This well 

drained soil is on uplands. It is shallow over a lime- and 

silica-cemented hardpan. It formed in loess. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 800 to 1,400 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is light brownish gray silt loam 

about 6 inches thick. The subsoil is light brownish gray silt 

loam about 4 inches thick. The substratum is light brownish 

gray gravelly silt loam about 6 inches thick. A hardpan is at 

a depth of about 16 inches. Depth to the hardpan ranges 

from 10 to 20 inches. The hardpan commonly is underlain 

by basalt, but in some areas it is underlain by sand and 

gravel. In some areas the surface layer is very fine sandy 

loam. 

Included in this unit are small areas of Shano, Burke, 

Roza, and Starbuck soils, areas of Rock outcrop, and 

areas of Scoon soils that have slopes of less than 5 

percent. 

Permeability of this Scoon soil is moderate above the 

hardpan and very slow through it. Available water 
capacity is low. Effective rooting depth is 10 to 20 

inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are grain, mint, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are suited to the 

soil in this unit. The type of irrigation system used depends 

on the kind of crop grown. Use of these irrigation systems 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. Shallow soil depth 

and steepness of slope make water management extremely 

important. To avoid loss of water and leaching of plant 

nutrients from over irrigation, applications of irrigation 

water should be adjusted to the available water capacity 

and the crop needs. 

Using a cropping system that includes close-growing, highresidue crops and growing mint in meadows rather than in 

rows reduce water erosion. Perennial cover crops are 

needed in orchards to reduce erosion. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production 

of forage is limited by low available water capacity. If the 

range is overgrazed, the proportion of preferred forage plants 

such as bluebunch wheatgrass decreases and the proportion 

of less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as chaining, railing, beating, chemical treatment, and 

prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition, but it is limited by low 

available water capacity. The unit should be seeded in fall 

using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites is depth to the hardpan, 

which hinders excavation. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

If this unit is used for septic tank absorption fields, the 

shallow depth to the hardpan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclasses IVe, 

irrigated, and VIe, nonirrigated. 

122-Scoon silt loam, 8 to 15 percent slopes. This 

well drained soil is on uplands. It is shallow over a lime- and 

silica-cemented hardpan. It formed in loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

800 to 1,400 feet. The average annual precipitation is 6 to 9 

inches, the average annual air 

temperature is about 50 degrees F, and the average 

frost-free season is 135 to 180 days. 

Typically, the surface layer is light brownish gray silt loam 

about 6 inches thick. The subsoil is light brownish gray silt 

loam about 4 inches thick. The substratum is light brownish 

gray gravelly silt loam about 6 inches thick. A hardpan is at 

a depth of about 16 inches. Depth to the hardpan ranges 

from 10 to 20 inches. The hardpan commonly is underlain by 

basalt, but in some areas it is underlain by sand and gravel. 

In some areas the surface layer is very fine sandy loam. 

Included in this unit are small areas of Shano, Roza, and 

Starbuck soils, areas of Rock outcrop, and areas of Scoon 

soils that have slopes of less than 8 percent or more than 

15 percent. 

Permeability of this Scoon soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 10 to 20 inches. Runoff is 

medium, and the hazard of water erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are grain and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are suited to 

the soil in this unit. The type of system used depends on the 

kind of crop grown. Use of these irrigation systems permits 

the even, controlled application of irrigation water, reduces 

runoff, and minimizes the risk of erosion. Shallow soil depth 

and steepness of slope make water management extremely 

important. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should be adjusted to the available water capacity and the 

crop needs. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water erosion. 

Perennial cover crops reduce erosion in orchards. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production of 

forage is limited by low available water capacity. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods as 

chaining, railing, beating, chemical treatment, and prescribed 

burning. Seeding is a suitable practice if the range 

vegetation is in poor condition, but it is difficult because of 

the low available water capacity. The unit should be seeded 

in fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites is shallow depth to the 

hardpan, which hinders excavation. Dustiness can be a 
problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, the 

shallow depth to the hardpan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

This map unit is in capability subclasses IVe, 

irrigated, and Vle, nonirrigated. 

123-Scoon silt loam, 15 to 30 percent slopes. This 

well drained soil is on uplands. It is shallow over a lime- and 

silica-cemented hardpan. It formed in loess. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 800 to 1,400 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is light brownish gray silt loam 

about 6 inches thick. The subsoil is light brownish gray silt 

loam about 4 inches thick. The substratum is light brownish 

gray gravelly silt loam about 6 inches thick. A hardpan is at a 

depth of about 16 inches. Depth to the hardpan ranges from 

10 to 20 inches. The hardpan commonly is underlain by 

basalt, but in some areas it is underlain by sand and gravel. 

In some areas the surface layer is very fine sandy loam. 

Included in this unit are areas of Shano, Roza, and 

Starbuck soils, areas of Rock outcrop, and areas of 

Scoon soils that have slopes of less than 15 percent. 

Permeability of this Scoon soil is moderate above the 

hardpan and very slow through it. Available water capacity 

is low. Effective rooting depth is 10 to 20 inches. Runoff is 

rapid, and the hazard of water erosion is high. 

This unit is used for irrigated hay, pasture, and orchard 

crops, rangeland, wildlife habitat, and homesites. The 

main irrigated crops are grasses and legumes. 

The main limitations for irrigated orchard, hay, and pasture 

crops are the shallow depth to the hardpan, steepness of 

slope, and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk of 

erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, 

the water intake rate, and the crop needs. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation reduces water 

erosion. Perennial cover crops reduce erosion in 

orchards. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production of 

forage is limited by low available water capacity. If the 

range is overgrazed, the proportion of preferred forage plants 

such as bluebunch wheatgrass decreases and the proportion 

of less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved with such methods 

as chaining, railing, beating, chemical treatment, and 

prescribed burning. Seeding is a suitable practice if the range 

vegetation is in poor condition; however, establishment of 

seedlings is difficult because of the low available water 

capacity. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are the shallow depth to the hardpan and 

steepness of slope. The pan hinders excavation. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as possible.

If this unit is used for septic tank absorption fields, the 

main limitations are the shallow depth to the hardpan and 

steepness of slope. The pan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Absorption lines should be 

installed on the contour. 

This map unit is in capability subclass Vle, irrigated 

and nonirrigated. 

124-Scooteney silt loam, 0 to 2 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

alluvium. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 650 to 1,300 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is 51 degrees F, and the average frost-free 

season is 135 to 170 days. 

Typically, the surface layer is brown silt loam about 6 

inches thick. The subsoil is pale brown silt loam about 16 

inches thick. The upper part of the substratum is light 

brownish gray gravelly fine sandy loam about 11 inches 

thick, and the lower part to a depth of 60 inches or more is 

light brownish gray very gravelly sandy loam. In some areas 

the surface layer is sandy loam. 

Included in this unit are small areas of Starbuck and 

Esquatzel soils. 

Permeability of this Scooteney soil is moderate. 

Available water capacity is moderately high. Effective 

rooting depth is 60 inches or more. Runoff is very slow, 

and the hazard of water erosion is slight. 

This unit is used for irrigated crops, wildlife habitat, 

and homesites. The main irrigated crops are corn, 

grapes, hops, and peas. Grasses and legumes are 

grown for hay, pasture, and seed. 

This unit has few limitations for irrigated crops. Furrow, 

corrugation, drip, and sprinkler irrigation systems are suited 

to the soil in this unit. The type of system used depends on 

the kind of crop grown. If surface irrigation systems are 

used, the risk of erosion can be minimized by keeping runs 

short. Use of sprinkler or drip irrigation 
permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to erosion. This makes the 

initial period of irrigation extremely critical. The water 

application rate should be reduced accordingly to help 

control erosion and the production of sediment. To avoid 

loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs.

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue on 

the surface reduce water erosion. A plowpan develops in this 

soil; however, it can be broken by chiseling or subsoiling 

when the soil is dry. Using vegetated filter strips at the end 

of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. 

This unit is well suited to homesite development. 

Dustiness may be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclass Ils, irrigated. 

125-Scooteney silt loam, 2 to 5 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

alluvium. The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 650 to 1,300 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air 

temperature is 51 degrees F, and the average frost-free 

season is 135 to 170 days. 

Typically, the surface layer is brown silt loam about 6 

inches thick. The subsoil is pale brown silt loam about 16 

inches thick. The upper part of the substratum is light 

brownish gray gravelly fine sandy loam about 11 inches thick, 

and the lower part to a depth of 60 inches or more is light 

brownish gray very gravelly sandy loam. In some areas the 

surface layer is sandy loam, and in some areas the subsoil 

and substratum are gravelly. 

Included in this unit are small areas of Finley, Scoon, 

Burke, and Esquatzel soils and Scooteney soils that have 

slopes of more than 5 percent. 

Permeability of this Scooteney soil is moderate. 

Available water capacity is moderately high. Effective 

rooting depth is 60 inches or more. Runoff is slow, and 

the hazard of water erosion is moderate. 

This unit is used for irrigated and nonirrigated crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are corn, grain, grapes, hops, and peas. 

Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitation for irrigated crops is the hazard of 

water erosion. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. If furrow 

or corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of erosion can be 

minimized by keeping runs short. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to erosion. This makes the 

initial period of irrigation extremely critical. The water 

application rate should be reduced accordingly to help 

control erosion and the production of sediment. To avoid 

loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue on 

the surface reduce water erosion. A plowpan develops in 

this soil; however, it can be broken by chiseling or 

subsoiling when the soil is dry. Using vegetated filter strips 

at the end of rows or using sediment ponds, or both, 

reduces the volume of sediment in the tailwater. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a 

cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, and shaping and seeding 

waterways to perennial grass. Drop structures are needed 

in a few places to stabilize the flow of runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, Thurber needlegrass, and 

big sagebrush. If the range is overgrazed, the proportion of 

less preferred forage plants such as balsamroot and big 

sagebrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods as 

railing, chaining, beating, chemical treatment, and 

prescribed burning. Seeding is a suitable practice if the 

range vegetation is in poor condition. The unit should be 

seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This unit is well suited to homesite development. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 
This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclass Ile, irrigated and 

IVe, nonirrigated. 

 126-Scooteney silt loam, 5 to 15 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

alluvium. The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 650 to 1,300 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air 

temperature is 51 degrees F, and the average frost-free 

season is 135 to 170 days. 

Typically, the surface layer is brown silt loam about 6 

inches thick. The subsoil is pale brown silt loam about 16 

inches thick. The upper part of the substratum is light 

brownish gray gravelly fine sandy loam about 11 inches 

thick, and the lower part to a depth of 60 inches or more is 

light brownish gray very gravelly sandy loam. In some 

areas the surface layer is sandy loam, and in some areas 

the subsoil and substratum are gravelly. 

Included in this unit are small areas of Finley, Scoon, and 

Burke soils and Scooteney soils that have slopes of more 

than 15 percent. 

Permeability of this Scooteney soil is moderate. 

Available water capacity is moderately high. 

Effective rooting depth is 60 inches or more. Runoff is 

medium, and the hazard of water erosion is moderate. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain early, 

stubble mulching, shaping waterways and seeding them 

to perennial grass, using terraces, and stripcropping. 

Drop structures are needed in a few places to stabilize the 

flow of runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, Thurber needlegrass, and 

big sagebrush. If the range is overgrazed, the proportion 

of preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as balsamroot and big sagebrush increases. Areas 

that are heavily infested with undesirable vegetation can 

be improved by such methods as railing, chaining, beating, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation for homesites is steepness of slope. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, 

slope can cause lateral seepage of effluent and 

subsequent surfacing in downslope areas. Absorption 

lines should be installed on the contour or across the 

slope. 

This map unit is in capability subclass IVe, 

nonirrigated. 

127-Scooteney cobbly silt loam, 0 to 5 percent 

slopes. This very deep, well drained soil is on terraces. It 

formed in alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 650 to 1,300 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is 51 degrees F, and the 

average frost-free season is 135 to 170 days. 

Typically, the surface layer is brown cobbly silt loam about 

6 inches thick. The subsoil is pale brown silt loam about 16 

inches thick. The upper part of the substratum is light 

brownish gray gravelly fine sandy loam about 11 inches 

thick, and the lower part to a depth of 60 inches or more is 

light brownish gray very gravelly sandy loam. In some areas 

the surface layer is sandy loam, silt loam, or gravelly silt 

loam. 

Included in this unit are areas of Finley and Esquatzel 

soils. 

Permeability of this Scooteney soil is moderate. Available 

water capacity is moderately high. Effective rooting depth is 

60 inches or more. Runoff is slow, and the hazard of water 

erosion is slight. 

This unit is used as rangeland, wildlife habitat, and 

homesites. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, and Thurber needlegrass. 

The main limitation for the production of forage is low annual 

precipitation. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as balsamroot and big sagebrush increases. Areas that 

are heavily infested with undesirable vegetation can be 

improved by such methods as chemical treatment and 

prescribed burning. Seedbed preparation can be difficult 

because of cobbles. Removal of the cobbles might be 

necessary. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is well suited to homesite development. It has few 

limitations. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclass Vle, 

nonirrigated. 

128-Selah silt loam, 2 to 5 percent slopes. This 

well drained soil is on high dissected terraces. It is 

moderately deep over a lime- and silica-cemented 
hardpan. It formed in loess and old alluvium. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,100 to 1,800 feet. The average annual 

precipitation is 8 to 12 inches, the average annual air 

temperature is about 52 degrees F, and the average frostfree season is 150 to 180 days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 7 inches thick. The subsoil is pale brown, light 

brownish gray, and brown silt loam and silty clay loam about 

27 inches thick. A lime- and silica-cemented hardpan is at a 

depth of about 34 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the hardpan is underlain by 

basalt, and in some areas it is underlain by sand and 

gravel. 

Included in this unit are small areas of Willis, Ritzville, 

and Roza soils. 

Permeability of this Selah soil is moderately slow above 

the hardpan and very slow through it. Available water 

capacity is moderately high. Effective rooting depth is 20 to 

40 inches. Runoff is slow, and the hazard of water erosion 

is moderate. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain and tree fruit. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan and the hazard of water erosion. Furrow, 

corrugation, drip, and sprinkler irrigation systems are 

suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and reduces erosion. If surface irrigation is 

used, erosion can be minimized by keeping runs short. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Using a cropping system that includes closegrowing, high-residue crops in the rotation and growing 

mint in meadows rather than in rows reduce water erosion. 

Annual or perennial cover crops reduce erosion in orchards 

and vineyards. A plowpan develops in the soil in this unit; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. Using vegetated filter strips at the end of 

rows or using sediment ponds, or both, reduces the volume 

of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitation is moderate depth to the hardpan, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitations for septic tank absorption fields 

are the moderate depth to the hardpan and slow 

permeability. Moderate depth to the hardpan limits the 

capacity of the absorption fields. Use of sandy backfill 

for the trench and long absorption lines helps to 

compensate for both of these limitations. 

The map unit is in capability subclass lIe, irrigated. 

129-Selah silt loam, 5 to 8 percent slopes. This well 

drained soil is on high dissected terraces. It is moderately 

deep over a lime- and silica-cemented hardpan. It formed in 

loess and old alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 1,100 to 1,800 feet. 

The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 52 degrees F, and 

the average frost-free season is 150 to 180 days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 7 inches thick. The subsoil is pale brown, light 

brownish gray, and brown silt loam and silty clay loam about 

27 inches thick. A lime- and silica-cemented hardpan is at a 

depth of about 34 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the hardpan is underlain by 

basalt, and in some areas it is underlain by sand and gravel. 

Included in this unit are small areas of Willis, Ritzville, 

and Roza soils. 

Permeability of this Selah soil is moderately slow above 

the hardpan and very slow through it. Available water 

capacity is moderately high. Effective rooting depth is 20 

to 40 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain and tree fruit. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are suited to the 

soil in this unit. The type of system used depends on the 

kind of crop grown. Use of these irrigation systems permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity and the crop needs. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. 

Growing cover crops reduces erosion in orchards and 

vineyards. A plowpan develops in this soil; however, it can 

be broken by chiseling or subsoiling when the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitation is moderate depth to the hardpan, which 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

depth to the hardpan and moderately slow permeability. 

Depth to the hardpan limits the capacity of 
the absorption fields. Use of sandy backfill for the trench 

and long absorption lines helps to compensate for both of 

these limitations. 

This map unit is in capability subclass llle, irrigated. 

130-Selah silt loam, 8 to 15 percent slopes. This well 

drained soil is on high dissected terraces. It is moderately 

deep over a lime- and silica-cemented hardpan. It formed in 

loess and old alluvium. The native vegetation is mainly 

grasses, forbs, and shrubs. Elevation is 1,100 to 1,800 

feet. The average annual precipitation is 8 to 12 inches, the 

average annual air temperature is about 52 degrees F, and 

the average frost-free season is 150 to 180 days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 7 inches thick. The subsoil is pale brown, light 

brownish gray, and brown silt loam and silty clay loam about 

27 inches thick. A lime- and silica-cemented hardpan is at a 

depth of about 34 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the hardpan is underlain by 

basalt, and in some areas it is underlain by sand and 

gravel. 

Included in this unit are small areas of Willis, Ritzville, and 

Roza soils. 

Permeability of this Selah soil is moderately slow above 

the hardpan and very slow through it. Available water 

capacity is moderately high. Effective rooting depth is 20 

to 40 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, 

grasses, legumes, and tree fruit. A cover crop is grown in 

orchards. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are 

suited to the soil in this unit. Use of these systems permits 

the even, controlled application of water, reduces runoff, 

and minimizes the risk of erosion. To avoid loss of water 

and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity and the crop needs. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. Growing 

annual or perennial cover crops reduces erosion in 

orchards. A plowpan develops in this soil; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by 

seeding fall grain early, stubble mulching, using 

terraces, and stripcropping. Seeding on the 

contour or across the slope slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Drop structures are needed in places to control the 

flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, big sagebrush, and needleandthread. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved with such methods 

as chaining, railing, beating, plowing, chemical treatment, and 

prescribed burning. Seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. 

The main limitation is moderate depth to the hardpan, 

which hinders excavation. Dustiness can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

depth to the hardpan and the moderately slow permeability. 

Depth to the hardpan limits the capacity of the absorption 

fields. Use of sandy backfill for the trench and long 

absorption lines helps to compensate for both of these 

limitations. Slope can cause lateral seepage and surfacing of 

effluent in downslope areas. 

This map unit is in capability subclasses IVe, irrigated, and 

Ille, nonirrigated. 

131-Selah silt loam, 15 to 30 percent slopes. This 

well drained soil is on high dissected terraces. It is 

moderately deep over a lime- and silica-cemented hardpan. 

It formed in loess and old alluvium. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,100 to 

1,800 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 52 

degrees F, and the average frost-free season is 150 to 180 

days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 7 inches thick. The subsoil is pale brown, light 

brownish gray, and brown silt loam and silty clay loam about 

27 inches thick. A lime- and silica-cemented hardpan is at a 

depth of about 34 inches. Depth to the hardpan ranges from 

20 to 40 inches. In some areas the hardpan is underlain by 

basalt, and in some areas it is underlain by sand and 

gravel. 

Included in this unit are small areas of Willis, Ritzville, 

and Roza soils. 

Permeability of the Selah soil is moderately slow above the 

hardpan and very slow through it. Available water capacity is 

moderately high. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 
This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain; grasses 

and legumes for hay, pasture, and seed; and tree fruit. A 

cover crop is grown in orchards. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are 

suited to the soil in this unit. Use of these systems permits 

the even, controlled application of water, reduces runoff, 

and minimizes the risk of erosion. To avoid loss of water 

and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to 

the available water capacity and the crop needs. 

Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces water 

erosion. Perennial cover crops are needed in orchards and 

vineyards to reduce erosion. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when the 

soil is dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, using diversions, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, big sagebrush, and needIeandthread. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as chaining, railing, beating, plowing, chemical 

treatment, and prescribed burning. Seeding is a suitable 

practice if the range vegetation is in poor condition. The unit 

should be seeded in fall using a drill. Adapted grasses 

and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are moderate depth to the hardpan and 

steepness of slope. The hardpan hinders excavation. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

The main limitations for septic tank absorption fields are 

moderate depth to the hardpan, steepness of slope, and 

moderately slow permeability. The moderate depth to 

the hardpan limits the capacity of the absorption fields. 

Slope can cause lateral seepage and surfacing of the 

effluent in downslope areas. Use of sandy backfill for 

the trench and long absorption lines helps to compensate 

for the moderate depth to the hardpan and the moderately 

slow permeability. 

This map unit is in capability subclass IVe, irrigated and 

nonirrigated. 

 132-Shano silt loam, 2 to 5 percent slopes. This very 

deep, well drained soil is on uplands. It formed in loess. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 650 to 1,200 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 170 days. 

Typically, the surface layer is brown silt loam about 4 

inches thick. The subsoil is pale brown silt loam about 26 

inches thick. The substratum to a depth of 60 inches or 

more is pale brown silt loam. In some areas the surface 

layer is fine sandy loam. 

Included in this unit are small areas of Warden, Burke, and 

Esquatzel soils and areas of Shano soils that have slopes of 

less than 2 percent. 

Permeability of this Shano soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used for irrigated and nonirrigated crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are corn, grain, grapes, hops, mint, and 

peas. Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitation for irrigated crops is the hazard of 

water erosion. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. If furrow 

or corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of erosion can be 

minimized by keeping runs short. Use of sprinkler and drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rates should be reduced accordingly to 

help control runoff, erosion, and the production of sediment. 

To avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 
close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Growing mint in meadows rather than in rows 

greatly reduces erosion. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. Using vegetated filter strips at the end of 

rows or using sediment ponds, or both, reduces the volume 

of sediment in the tailwater. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall grain 

early and stubble mulching. Seeding on the contour or 

across the slope slows runoff and reduces erosion when the 

snow melts rapidly while the soil is still frozen. Drop 

structures are needed in a few places to stabilize the flow of 

runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such as 

bluebunch wheatgrass decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as railing, chaining, beating, plowing, chemical 

treatment, and prescribed burning. Seeding is a suitable 

practice if the range vegetation is in poor condition. This 

unit should be seeded in fall using a drill. Adapted grasses 

and legumes should be seeded. 

This unit is well suited to homesite development. It has 

few limitations. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclass Ile, irrigated, 

and IVe, nonirrigated. 

133-Shano silt loam, 5 to 8 percent slopes. This very 

deep, well drained soil is on uplands. It formed in loess. The 

native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 650 to 1,200 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 170 days. 

Typically, the surface layer is brown silt loam about 4 

inches thick. The subsoil is pale brown silt loam about 26 

inches thick. The substratum to a depth of 60 inches or 

more is pale brown silt loam. In some areas the surface 

layer is loam. 

Included in this unit are small areas of Warden and Burke 

soils and areas of Shano soils that have slopes of more than 

8 percent. 

Permeability of this Shano soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used for irrigated crops and as rangeland, 

wildlife habitat, and homesites. The main irrigated crops are 

grain, grapes, peas, and mint. Grasses and legumes are 

grown for hay, pasture, and seed. 

 The main limitations for irrigated crops are 

steepness of slope and the hazard of water erosion. 

Sprinkler and drip irrigation systems are suited to the 

soil in this unit. The type of system used depends on 

the kind of crop grown. Use of these irrigation systems 

permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs.

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue on 

the surface reduce water erosion. Cover crops reduce 

erosion in orchards and vineyards. A plowpan develops in 

this soil; however, it can be broken by chiseling or subsoiling 

when the soil is dry. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such as 

bluebunch wheatgrass decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as railing, chaining, beating, plowing, 

chemical treatment, and prescribed burning. Seeding is 

a suitable practice if the range vegetation is in poor 

condition. The unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is well suited to homesite development. It has 

few limitations. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclasses Ille, irrigated, and 

IVe, nonirrigated. 

134-Shano silt loam, 8 to 15 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess. The native vegetation is mainly grasses, forbs, 
and shrubs. Elevation is 650 to 1,200 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 170 days. 

Typically, the surface layer is brown silt loam about 4 

inches thick. The subsoil is pale brown silt loam about 26 

inches thick. The substratum to a depth of 60 inches or 

more is pale brown silt loam. In some areas the surface 

layer is fine sandy loam. 

Included in this unit are small areas of Warden, 

Scooteney, and Burke soils and Shano soils that have 

slopes of less than 8 percent. 

Permeability of this Shano soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for irrigated and nonirrigated crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are grain and grapes. Grasses and legumes 

are grown for hay, pasture, and seed. A cover crop is grown 

in orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity and the crop needs.

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. Annual 

or perennial cover crops reduce erosion in orchards and 

vineyards. A plowpan develops in this soil; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, divided-slope farming, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial grass.

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as railing, chaining, beating, plowing, 

chemical treatment, and prescribed burning. 

Range seeding is a suitable practice if the range vegetation 

is in poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation for homesites is steepness of slope. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If the unit is used for septic tank absorption fields, 

steepness of slope can cause lateral seepage and 

surfacing of effluent in downslope areas. Absorption 

lines should be installed on the contour. 

This map unit is in capability subclass IVe, irrigated 

and nonirrigated. 

135-Shano silt loam, 15 to 30 percent slopes. This 

very deep, well drained soil is on uplands. It formed in loess. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 600 to 1,200 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 170 days. 

Typically, the surface layer is brown silt loam about 4 

inches thick. The subsoil is pale brown silt loam about 26 

inches thick. The substratum to a depth of 60 inches or more 

is pale brown silt loam. 

Included in this unit are areas of Warden and Burke 

soils. 

Permeability of this Shano soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain early, 

stubble mulching, divided-slope farming, and stripcropping. 

Seeding on the contour or across the slope slows runoff and 

reduces erosion when the snow melts rapidly while the soil 

is still frozen. Drop structures are needed in places to control 

the flow of runoff in waterways. Waterways should be shaped 

and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as railing, chaining, beating, plowing, chemical treatment, 

and prescribed burning. Range seeding is a suitable 

practice if the range 
vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites is steepness of slope. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as possible.

If this unit is used for septic tank absorption fields, 

steepness of slope can cause lateral seepage and 

surfacing of effluent in downslope areas. 

This map unit is in capability subclass IVe, 

nonirrigated. 

136-Simcoe silt loam, 5 to 15 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed in 

loess and in residuum derived from basalt and a small 

amount of volcanic ash. Slope is dominantly about 10 

percent. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 1,200 to 2,300 feet. The average annual 

precipitation is 10 to 12 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 120 to 170 days. 

Typically, the surface layer is brown silt loam about 3 

inches thick. The upper part of the subsoil is brown silt loam 

about 11 inches thick, and the lower part is brown silt loam 

about 13 inches thick. Basalt is at a depth of about 27 

inches. Depth to basalt ranges from 20 to 40 inches. In 

some areas the surface layer is loam. 

Included in this unit are areas of Harwood, Rock Creek, 

and Selah soils, areas of Rock outcrop, and areas of 

Simcoe soils that have slopes of more than 15 percent. 

Permeability of this Simcoe soil is moderately slow. 

Available water capacity is moderate. Effective rooting 

depth is 20 to 40 inches. Runoff is medium, and the 

hazard of water erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain and tree fruit. 

Grasses and legumes are grown for hay, pasture, and 

seed. A cover crop is grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope, depth to rock, and the hazard of water erosion. 

Sprinkler and drip irrigation systems are suited to the soil in 

this unit. Use of these systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should be adjusted to the available water capacity and the 

crop needs. 

Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces 

water erosion. Annual or perennial cover crops reduce 

erosion in orchards. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, a 

cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, using terraces and 

diversions, and stripcropping. Seeding on the contour or 

across the slope slows runoff and reduces erosion when the 

snow melts rapidly while the soil is still frozen. Drop 

structures are needed in places to control the flow of runoff 

in waterways. Waterways should be shaped and seeded to 

perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as chaining, railing, beating, plowing, chemical 

treatment, and prescribed burning. Seeding is a suitable 

practice if the range vegetation is in poor condition. The 

unit should be seeded in fall using a drill. Adapted grasses 

and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is moderate depth to rock, which hinders 

excavation. Dustiness can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitations for septic tank absorption fields are 

moderate depth to rock and moderately slow permeability. 

The moderate depth to rock limits the capacity of the 

absorption fields. Use of sandy backfill for the trench and 

long absorption lines helps to compensate for the 

moderately slow permeability. Slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

Absorption lines should be placed on the contour or across 

the slope. 

This map unit is in capability subclasses IVe, 

irrigated, and Ille, nonirrigated. 

137-Simcoe silt loam, 15 to 30 percent slopes. This 

moderately deep, well drained soil is on uplands. It formed 

in loess and in residuum derived from basalt and contains a 

small amount of volcanic ash. Slope is dominantly about 20 

percent. The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 1,200 to 2,300 feet. The 

average annual precipitation is 10 to 12 inches, the average 

annual air temperature is about 50 degrees F, and the 

average frost-free season is 120 to 170 days. 

Typically, the surface layer is brown silt loam about 3 

inches thick. The subsoil is brown silt loam about 24 inches 

thick. Basalt is at a depth of about 27 inches. Depth to 

basalt ranges from 20 to 40 inches. In some areas the 

surface layer is loam, and in some areas the subsoil is 

gravelly. 
Included in this unit are areas of Rock Creek and Selah 

soils, areas of Rock outcrop, and areas of Simcoe soils that 

have slopes of more than 30 percent. 

Permeability of this Simcoe soil is moderately slow. 

Available water capacity is moderate. Effective rooting depth 

is 20 to 40 inches. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain and tree 

fruit. Grasses and legumes are grown for hay, 

pasture, and seed. A cover crop is grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope, depth to rock, and the hazard of water erosion. 

Sprinkler and drip irrigation systems are suited to the soil in 

this unit. Use of these irrigation systems permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity and the crop needs. Using a cropping system that 

includes close-growing, high-residue crops in the rotation 

reduces water erosion. Perennial cover crops reduce erosion 

in orchards and vineyards. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, divided-slope farming, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial grass.

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such as 

bluebunch wheatgrass decreases and the proportion of less 

preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as chaining, railing, beating, plowing, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are moderate depth to rock and steepness 

of slope. The bedrock hinders excavation. Dustiness can be 

a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

moderate depth to rock, steepness of slope, and 

moderately slow permeability. The moderate depth to rock 

limits the capacity of the absorption fields. Use of sandy 

backfill for the trench and long absorption lines helps to 

compensate for the moderately slow permeability. 

Steepness of slope can cause lateral seepage and 

surfacing of the effluent in downslope areas. 

This map unit is in capability subclass IVe, irrigated and 

nonirrigated. 

138-Sinloc fine sandy loam, 0 to 2 percent slopes. 

This very deep, artificially drained soil is on terraces. It 

formed in lacustrine sediment and has a mantle of loess. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 650 to 1,200 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frost-free

season is 135 to 180 days. 

Typically, the surface layer is dark grayish brown, 

strongly alkaline fine sandy loam about 3 inches thick. The 

subsoil is dark grayish brown, strongly alkaline silt loam 

about 12 inches thick. The upper part of the substratum is 

dark grayish brown, strongly alkaline and moderately 

alkaline, stratified silt loam and fine sandy loam about 30 

inches thick, and the lower part to a depth of 60 inches or 

more is dark grayish brown, moderately alkaline loamy fine 

sand. 

Included in this unit are areas of Warden, Hezel, Shano, 

Harwood, Burke, Outlook, and Wiehl soils and areas of Sinloc 

soils that have not been artificially drained. Included areas 

make up about 20 percent of the total acreage. 

Permeability of this Sinloc soil is moderate. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 18 to 42 

inches from May to October. Runoff is slow, and the hazard 

of erosion is slight. The hazard of soil blowing is high. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. In areas that are drained, leached of 

excessive salts, and irrigated, the main irrigated crops are 

asparagus, corn, grain, hops, mint, and peas. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are wetness and 

the hazard of soil blowing. Furrow, corrugation, and sprinkler 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. If 

surface irrigation systems are used, the risk of erosion can 

be minimized by keeping runs short. Use of sprinkler 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. To avoid 

loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. 
Proper timing of minimum tillage and return of crop 

residue to the soil reduce compaction, help to maintain or 

improve the organic matter content, help to maintain tilth, 

and improve the water infiltration rate. The soil in this unit 

should be protected with plant cover or residue in spring 

when the soil is most susceptible to soil blowing. Use of 

straw, manure, or other waste material as a mulch also 

reduces soil blowing. Using vegetated filter strips at the end 

of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. A plowpan may develop 

in this soil; however, it can be broken by chiseling or 

subsoiling when the soil is dry. Deep-rooted crops are suited 

to areas where a drainage system has been installed and 

is adequately maintained. If the drainage system is not 

maintained, the soil has a seasonal high water table and a 

high salt content during the irrigation season. 

This unit is poorly suited to homesite development. The 

main limitation for building sites and septic tank absorption 

fields is wetness. Drainage is needed if roads and building 

foundations are constructed. Wetness can be reduced by 

installing drain tile around the footings. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. The plants used as ground cover should be 

adapted to the salt- and alkali-affected condition of the soil. 

The seasonal high water table increases the possibility of 

failure of septic tank absorption fields. It also increases the 

risk of contaminating water supplies as a result of seepage. 

Cutbanks are not stable and are subject to caving in. 

This map unit is in capability subclass Illw, irrigated. 

139-Sinloc silt loam, 0 to 2 percent slopes. This very 

deep, artificially drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 650 to 1,200 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is dark grayish brown, 

strongly alkaline silt loam about 3 inches thick. The subsoil 

is dark grayish brown, strongly alkaline silt loam about 

12 inches thick. The upper part of the substratum is dark 

grayish brown, stratified, strongly alkaline and 

moderately alkaline silt loam and very fine sandy loam about 

30 inches thick, and the lower part to a depth of 60 inches 

or more is dark grayish brown, moderately alkaline loamy 

fine sand. 

Included in this unit are small areas of Warden, Hezel, 

Shano, Harwood, Burke, Outlook, and Wiehl soils and areas 

of Sinloc soils that have not been artificially drained. 

Permeability of this Sinloc soil is moderate. Available water

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 18 to 

42 inches from May to October. Runoff is slow, and the 

hazard of water erosion is slight. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. Where drained, leached of excessive 

salts, and irrigated, the main irrigated crops are asparagus, 

corn, grain, hops, mint, and peas. Grasses and legumes 

are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is wetness. Furrow, 

corrugation, and sprinkler irrigation systems are suited to 

the soil in this unit. The type of system used depends on the 

kind of crop grown. If surface irrigation systems are used, 

the risk of erosion can be minimized by keeping runs short. 

Use of sprinkler irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should also be adjusted to the available water capacity and 

the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil reduce compaction, help to maintain or improve the 

organic matter content, help to maintain tilth, improve the 

water infiltration rate, and reduce erosion. Using vegetated 

filter strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. A 

plowpan develops in the soil in this unit; however, it can be 

broken by chiseling or subsoiling when the soil is dry. Deeprooted crops are suited to areas where a drainage system 

has been installed and is adequately maintained. If the 

drainage system is not maintained, the soil has a seasonal 

high water table during the irrigation season and has a high 

content of salt. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and for septic tank absorption 

fields is wetness. Drainage is needed if roads and building 

foundations are constructed. Wetness can be reduced by 

installing drain tile around footings. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. The plants used as ground cover should be 

adapted to saline conditions. The seasonal high water table 

increases the possibility of failure of septic tank absorption 

fields. It also increases the risk of contaminating water 

supplies as a result of seepage. Cutbanks are not stable and 

are subject to caving in. 

This map unit is in capability subclass IIIw, irrigated. 

140-Sinloc silt loam, 2 to 5 percent slopes. This very 

deep, artificially drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

650 to 1,200 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is dark grayish brown, 

strongly alkaline silt loam about 3 inches thick. The 
subsoil is dark grayish brown, strongly alkaline silt loam 

about 12 inches thick. The upper part of the substratum is 

dark grayish brown, stratified, strongly alkaline and 

moderately alkaline silt loam and very fine sandy loam 

about 30 inches thick, and the lower part to a depth of 60 

inches or more is dark grayish brown, moderately alkaline 

loamy fine sand. 

Included in this unit are small areas of Warden, Hezel, 

Shano, Harwood, Burke, Outlook, and Wiehl soils, 

areas of Sinloc soils that have not been artificially drained, 

and areas of Sinloc soils that have slopes of more than 5 

percent. 

Permeability of this Sinloc soil is moderate. Available 

water capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 18 to 42 

inches from May to October. Runoff is medium, and the 

hazard of water erosion is moderate. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. In areas that have been drained, leached 

of excessive salts, and irrigated, the main irrigated crops 

are asparagus, corn, grain, hops, mint, and peas. 

Grasses and legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are wetness and 

the hazard of water erosion. Deep-rooted crops are suited to 

areas where a drainage system has been installed. If the 

drainage system is not maintained, this soil has a seasonal 

high water table during the irrigation season and has a high 

content of salt. If furrow and corrugation irrigation 

systems are used, runs should be on the contour or 

across the slope. The risk of erosion can be minimized by 

keeping runs short. Use of a sprinkler irrigation system 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This makes 

the initial period of irrigation extremely critical. The water 

application rate should be reduced accordingly to help 

control erosion and the production of sediment. To avoid 

loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Tilling when the moisture content of the soil is optimal and 

returning crop residue to the soil reduce compaction, help to 

maintain or improve the organic matter content, help to 

maintain tilth, and improve the water infiltration rate. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation and maintaining crop residue on the 

surface reduce water erosion. Growing mint in meadows 

rather than in rows greatly reduces erosion. A plowpan 

develops in this soil; however, it can be broken by chiseling 

or subsoiling 

when the soil is dry. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. 

 This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption fields 

is wetness. Drainage is needed if roads and building 

foundations are constructed. Wetness can be reduced by 

installing drain tile around the footings. Dustiness can be a 

problem during construction on large building sites; therefore, 

these sites should be disturbed as little as possible. The 

plants used as ground cover should be adapted to saline and 

alkaline conditions. The seasonal high water table increases 

the possibility of failure of septic tank absorption fields. It also 

increases the risk of contaminating water supplies as a result 

of seepage. Cutbanks are not stable and are subject to 

caving in. 

This map unit is in capability subclass Illw, irrigated. 

141-Sinloc silt loam, 5 to 8 percent slopes. This very 

deep, artificially drained soil is on terraces. It formed in 

lacustrine sediment. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 650 to 1,200 feet. The 

average annual precipitation is 6 to 9 inches, the average 

annual air temperature is about 50 degrees F, and the 

average frost-free season is 135 to 180 days. 

Typically, the surface layer is dark grayish brown, strongly 

alkaline silt loam about 3 inches thick. The subsoil is dark 

grayish brown, strongly alkaline silt loam about 12 inches 

thick. The upper part of the substratum is dark grayish 

brown, stratified, strongly alkaline and moderately alkaline 

silt loam and very fine sandy loam about 30 inches thick, 

and the lower part to a depth of 60 inches or more is dark 

grayish brown, moderately alkaline loamy fine sand. The 

soil is strongly alkaline or moderately alkaline throughout. 

Included in this unit are small areas of Warden, Hezel, 

Shano, Harwood, Burke, and Wiehl soils and areas of Sinloc 

soils that have not been artificially drained. 

Permeability of this Sinloc soil is moderate. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 18 to 42 

inches during May to October. Runoff is medium, and the 

hazard of water erosion is moderate. 

This unit is used for irrigated crops, wildlife habitat, and 

homesites. In areas that have been drained, leached of 

excessive salts, and irrigated, the main irrigated crops are 

corn, grain, and peas. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are wetness, 

steepness of slope, and the hazard of water erosion. Deeprooted crops are suited to areas where a drainage system 

has been installed and is adequately maintained. Dikes are 

effective in diverting floodwater. If drainage systems are not 

maintained, the soil in this unit has a seasonal high water 

table during the irrigation season and a high content of salt. 
Sprinkler and drip irrigation systems are suited to the soil 

in this unit. The type of irrigation system used depends on 

the kind of crop grown. Use of these systems permits the 

even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. Cultivation prior to irrigation 

improves the water infiltration rate; however, the fine soil 

particles dislodged during cultivation are highly susceptible 

to water erosion. This makes the initial period of irrigation 

extremely critical. The water application rate should be 

reduced accordingly to help control erosion and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from overirrigation, applications of irrigation 

water should also be adjusted to the available water 

capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, improve the water infiltration rate, and 

reduce erosion. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. A plowpan develops in this soil; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is wetness. Drainage is needed if roads and building 

foundations are constructed. Wetness can be reduced by 

installing drain tile around the footings. Dustiness can be a 

problem during construction on large building sites; therefore, 

these sites should be disturbed as little as possible. The 

plants used as ground cover should be adapted to saline 

conditions. The high water table increases the possibility of 

failure of septic tank absorption fields. It also increases the 

risk of contaminating water supplies as a result of seepage. 

Cutbanks are not stable and are subject to caving in. 

This map unit is in capability subclass Illw, irrigated. 

142-Starbuck silt loam, 2 to 15 percent slopes. This 

shallow, well drained soil is on uplands. It formed in loess. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 700 to 2,000 feet. The average annual 

precipitation ranges from 6 to 11 inches, the average annual 

air temperature is about 50 degrees F, and the average 

frost-free season is 135 to 170 days. 

Typically, the surface layer is brown silt loam about 6 

inches thick. The subsoil is pale brown silt loam and 

gravelly silt loam about 10 inches thick. Basalt is at a 

depth of about 16 inches. Depth to basalt ranges from 12 

to 20 inches. In some areas the surface layer is stony. 

Included in this unit are areas of Scoon, Harwood, Burke, 

and Wiehl soils, areas of Rock outcrop, and areas of 

Starbuck soils that have slopes of less than 2 percent or 

more than 15 percent. 

Permeability of this Starbuck soil is moderate. 

Available water capacity is low. The effective rooting 

depth is 12 to 20 inches. Runoff is medium, and the 

hazard of water erosion is moderate. 

This unit is used for irrigated crops, rangeland, wildlife 

habitat, and homesites. The main irrigated crop is grain. 

Grasses and legumes are grown for hay, pasture, and seed.

The main limitations for irrigated crops are depth to rock, 

steepness of slope, and the hazard of water erosion. 

Sprinkler irrigation is suited to the soil in this unit. It permits 

the even, controlled application of water, reduces runoff, 

and minimizes the risk of erosion. To avoid loss of water 

and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue in 

the soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces water 

erosion. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production of 

forage is limited by low available water capacity. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods as 

chaining, railing, beating, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill when the moisture content of the soil is 

optimum. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. 

The main limitation for homesites is shallow depth to 

rock, which hinders excavation. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, 

shallow depth to bedrock limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclasses IVe, irrigated, and 

Vle, nonirrigated. 

143-Starbuck-Rock outcrop complex, 0 to 45 percent 

slopes. This map unit is on uplands. Slope dominantly is 

about 25 percent. The native vegetation is mainly grasses, 

forbs, and shrubs. Elevation is 700 to 2,000 feet. The 

average annual precipitation is 6 to 10 inches, the average 

annual air temperature is about 50 
degrees F, and the average frost-free season is 135 to 

170 days. 

This unit is about 50 percent Starbuck silt loam and 

about 25 percent Rock outcrop. The components of this unit 

are so intricately intermingled that it was not practical to 

map them separately at the scale used. 

Included in this unit are areas of Kiona, Scoon, Bakeoven, 

Prosser, Ritzville, Harwood, Burke, Wiehl, and Shano soils. 

Also included are small areas of somewhat poorly drained 

soils in basins. Included areas make up about 25 percent of 

the total acreage. 

The Starbuck soil is shallow and well drained. It formed in 

loess overlying basalt. Typically, the surface layer is brown 

silt loam about 6 inches thick. The subsoil is pale brown silt 

loam and gravelly silt loam about 10 inches thick. Basalt is 

at a depth of about 16 inches. Depth to basalt ranges from 

12 to 20 inches. 

Permeability of the Star buck Soil is moderate. 

Available water capacity is low. The effective rooting 

depth is 12 to 20 inches. Runoff is medium, and the 

hazard of water erosion is moderate. 

Rock outcrop is areas of exposed bedrock. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. The production of 

forage is limited by low available water capacity and areas of 

Rock outcrop. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass 

decreases and the proportion of less preferred forage plants 

such as big sagebrush and rabbitbrush increases. Areas that 

are heavily infested with undesirable vegetation can be 

improved with such methods as chemical treatment and 

prescribed burning. 

Range seeding on the Starbuck soil is a suitable practice if 

the range vegetation is in poor condition, but it is difficult 

because of the areas of Rock outcrop. Most areas of the soil 

can be seeded with a drill. The unit should be seeded in fall. 

Adapted grasses and legumes should be seeded. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

144-Starbuck-Rock outcrop complex, 45 to 60 

percent slopes. This map unit is on uplands. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 700 to 2,000 feet. The average annual 

precipitation is 6 to 10 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 170 days. 

This unit is about 45 percent Starbuck silt loam and 

about 35 percent Rock outcrop. The components of this 

unit are so intricately intermingled that it was not practical 

to map them separately at the scale used. 

Included in this unit are areas of Kiona, Bakeoven, 

Ritzville, and Shano soils. Included areas make up about 20 

percent of the total acreage. 

The Starbuck soil is shallow and well drained. It formed in 

loess overlying basalt. Typically, the surface layer is brown 

silt loam about 6 inches thick. The subsoil is pale brown silt 

loam and gravelly silt loam about 10 inches thick. Basalt is 

at a depth of about 16 inches. Depth to basalt ranges from 

12 to 20 inches. 

Permeability of the Starbuck soil is moderate. Available 

water capacity is low. Effective rooting depth is 12 to 20 

inches. Runoff is rapid, and the hazard of water erosion is 

high. 

Rock outcrop is areas of exposed bedrock. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation of the Starbuck soil is 

mainly bluebunch wheatgrass and Sandberg bluegrass. 

The production of forage is limited by steepness of slope 

and areas of Rock outcrop. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. Brush control is mainly limited to aerial application 

of chemicals or prescribed burning. Steepness of slope and 

the areas of Rock outcrop limit access by livestock and 

promote overgrazing of the less sloping areas. Proper 

placement of salt licks, stock water tanks, and fences 

promote more uniform distribution of grazing. Aerial seeding 

of the Starbuck soil may be desirable. Seedings generally are 

most successful in fall. Adapted grasses and legumes should 

be seeded. 

This map unit is in capability subclass VIIs, 

nonirrigated. 

145-Sutkin stony loam, 0 to 25 percent slopes. 

This very deep, well drained soil is on smooth 

mountaintops. It formed in colluvium and residuum derived 

dominantly from basalt and containing small amounts of 

loess. The native vegetation is mainly conifers, grasses, 

forbs, and shrubs. Elevation is 3,400 to 4,400 feet. The 

average annual precipitation is 18 to 22 inches, the 

average annual air temperature is about 43 degrees F, and 

the average length of the growing season, at 28 degrees 

F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1 /2 inch thick. The 

surface layer is dark brown stony loam about 10 inches 

thick. The subsoil is dark yellowish brown very cobbly loam 

and extremely cobbly loam about 28 inches thick. The 

substratum to a depth of 60 inches or more is dark yellowish 

brown extremely cobbly loam. In some areas the subsoil is 

loam, gravelly loam, or very cobbly clay. 

Included in this unit are areas of Sapkin and Bocker soils 

and areas of Sutkin soils that have slopes of 25 to 45 

percent. Included areas make up about 10 percent of the 

total acreage. 

Permeability of this Sutkin soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate.
This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. On the basis of a 100-year site curve, 

the mean site index is 67 for ponderosa pine and 81 for 

Douglas-fir. Yield tables for normal, even-aged, unmanaged 

stands indicate that the mean annual increment at 

culmination (CMAI) for trees 0.6 inch in diameter and larger 

is 52 cubic feet per acre for ponderosa pine at age 50 and 

71 cubic feet per acre for Douglas-fir at age 40. The mean 

annual increment for trees 6.6 inches in diameter and larger 

at 80 years of age is 40 cubic feet per acre for ponderosa 

pine and 57 cubic feet per acre for Douglas-fir. However, the 

typical basal area of stands on this unit is about 90 percent 

that of normal stands, and the total yield is correspondingly 

lower. 

The main limitation for the harvesting of timber is a short 

period of seasonal soil wetness. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads 

require suitable surfacing for year-round use. Rock for 

road construction is not readily available on this unit. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine and Douglas-fir seedlings. If 

seed trees are present, natural reforestation of cutover areas 

by ponderosa pine and Douglas-fir occurs infrequently. The 

droughtiness of the soil increases seedling mortality, 

especially on south- and southwest-facing slopes. 

The common forest understory plants are pinegrass, elk 

sedge, yarrow, ceanothus, and Oregon-grape. The 

crown density in the areas where the woodland site index 

was measured is 30 percent. This unit is well suited to 

grazing and browsing. Seeding to adapted grazable 

vegetation following logging or burning late in summer or in 

fall generally is most successful. 

This map unit is in capability subclass Vls, 

nonirrigated. 

146-Sutkin stony loam, 25 to 45 percent slopes. This 

very deep, well drained soil is on mountainsides. It formed in 

colluvium and residuum derived dominantly from basalt 

and small amounts of loess. The native vegetation is 

mainly conifers, grasses, forbs, and shrubs. Elevation is 

2,800 to 4,800 feet. The average annual precipitation is 18 to 

22 inches, the average annual air temperature is about 43 

degrees F, and the average length of the growing season, at 

28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1/2 inch thick. The 

surface layer is dark brown stony loam about 10 inches thick. 

The subsoil is dark yellowish brown very cobbly loam and 

extremely cobbly loam about 28 inches thick. 

The substratum to a depth of 60 inches or more is dark 

yellowish brown extremely cobbly loam. In some areas the 

subsoil is very cobbly clay. 

Included in this unit are about 10 percent Sapkin soils, 

about 5 percent Bocker soils, areas of Rock outcrop and 

Rubble land, and areas of Sutkin soils that have slopes of 

less than 25 percent or more than 45 percent. 

Permeability of this Sutkin soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. Among the trees of limited extent are 

western larch and Oregon white oak. On the basis of a 100-

year site curve, the mean site index is 67 for ponderosa pine 

and 81 for Douglas-fir. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 52 . cubic feet per acre for ponderosa pine at age 50 

and 71 cubic feet per acre for Douglas-fir at age 40. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 45 cubic feet per acre for 

ponderosa pine and 60 cubic feet per acre for Douglas-fir. 

However, the typical basal area of stands on this unit is about 

80 percent that of normal stands, and total yield is 

correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. Cable yarding systems are safer, 

and they disturb the soil less. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads require 

suitable surfacing for year-round use. Rock for road 

construction is available in included areas of Rock outcrop 

and Rubble land. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine and Douglas-fir seedlings. If 

seed trees are present, natural reforestation of cutover areas 

by ponderosa pine and Douglas-fir occurs periodically. The 

droughtiness of the soil increases seedling mortality, 

especially on south- and southwest-facing slopes. 

The common forest understory plants are pinegrass, elk 

sedge, bitterbrush, yarrow, Oregon-grape, common 

snowberry, and ceanothus. The crown density in the areas 

where the woodland site index was measured is 25 percent. 

This unit is suited to grazing and browsing. Seeding to 

adapted grazable vegetation following logging or burning late 

in summer or in fall generally is most successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 
147-Sutkin stony loam, 45 to 65 percent slopes. This 

very deep, well drained soil is on mountainsides. It formed in 

colluvium and residuum derived dominantly from basalt and 

containing small amounts of loess. The native vegetation is 

mainly conifers, grasses, forbs, and shrubs. Elevation is 

3,400 to 4,600 feet. The average annual precipitation is 18 

to 22 inches, the average annual air temperature is about 

43 degrees F, and the average length of the growing 

season, at 28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1/2 inch thick. The 

surface layer is dark brown stony loam about 10 inches 

thick. The subsoil is dark yellowish brown very cobbly loam 

and extremely cobbly loam about 28 inches thick. The 

substratum to a depth of 60 inches or more is dark 

yellowish brown extremely cobbly loam. 

Included in the unit are areas of Sapkin soils, Rock 

outcrop, Rubble land, and Sutkin soils that have slopes of 

less than 45 percent. Included areas make up about 15 

percent of the total acreage. 

Permeability of this Sutkin soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main woodland 

species on this unit. Among the trees of limited extent are 

Oregon white oak, western larch, and grand fir. On the basis 

of a 100-year site curve, the mean site index is 67 for 

ponderosa pine and 81 for Douglas-fir. Yield tables for 

normal, even-aged, unmanaged stands indicate that the 

mean annual increment at culmination (CMAI) for trees 0.6 

inch in diameter and larger is 52 cubic feet per acre for 

ponderosa pine at age 50 and 71 cubic feet per acre for 

Douglas-fir at age 40. The mean annual increment for trees 

6.6 inches in diameter and larger at 80 years of age is 40 

cubic feet per acre for ponderosa pine and 65 cubic feet per 

acre for Douglas-fir. However, the typical basal area of 

stands on this unit is about 70 percent that of normal 

stands, and the total yield is correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which restricts the use of wheeled and 

tracked equipment in skidding operations. Cable yarding 

systems generally are safer, and they disturb the soil less. 

Unsurfaced roads and skid trails are slippery when wet, and 

they may be impassable during spring runoff or in rainy 

periods. Logging roads require suitable surfacing for yearround use. Rock for road construction is available in 

included areas of Rock outcrop and Rubble land. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine and Douglas-fir seedlings. If 

seed trees are present, natural reforestation of cutover 

areas by ponderosa pine and Douglas-fir occurs 

periodically. The droughtiness of the soil increases seedling 

mortality, especially on south- and southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, bitterbrush, common snowberry, and Oregongrape. The crown density in the areas where the woodland 

site index was measured is 35 percent. This unit is well 

suited to browsing; however, steepness of slope limits 

access by livestock. Seeding to adapted grazable vegetation 

following logging or burning late in summer or in fall 

generally is most successful. Because of the steepness of 

slope, broadcast seeding should be used. 

Seeding of adapted grazable plants following logging or

burning reduces soil erosion, preserves water quality, and 

increases the production of understory. Seeding late in 

summer or in fall is most successful. The presence of

logging debris and steepness of slope limit seeding. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

148-Sutkin stony loam, 25 to 45 percent south 

slopes. This very deep, well drained soil is on 

mountainsides and in canyons. It formed in colluvium and 

residuum derived dominantly from basalt and small 

amounts of loess. The native vegetation is mainly conifers, 

grasses, forbs, and shrubs. Elevation is 2,800 to 4,000 feet. 

The average annual precipitation is 18 to 22 inches, the 

average annual air temperature is about 43 degrees F, and 

the average length of the growing season, at 28 degrees F, 

is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1/2 inch thick. The 

surface layer is dark brown stony loam about 10 inches 

thick. The subsoil is dark yellowish brown very cobbly loam 

and extremely cobbly loam about 28 inches thick. The 

substratum to a depth of 60 inches or more is dark 

yellowish brown extremely cobbly loam. In some areas the 

subsoil is very cobbly clay, and in some small concave areas 

on terraces the subsoil is loam or gravelly loam. 

Included in this unit are areas of Sapkin and Bocker 

soils, areas of Rubble land and Rock outcrop, small convex 

areas of soils that have slopes of more than 45 percent, 

and small concave areas of soils that have slopes of less 

than 25 percent. Included areas make up about 15 percent 

of the total acreage. 

Permeability of this Sutkin soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main 

woodland species on this unit. Numerous patches of 
Oregon white oak are also present. On the basis of a 100-

year site curve, the mean site index is 49 for ponderosa pine 

and 65 for Douglas-fir. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual 

increment at culmination (CMAI) for trees 0.6 inch in 

diameter and larger is 37 cubic feet per acre for ponderosa 

pine at age 60 and 50 cubic feet per acre for Douglas-fir at 

age 50. The mean annual increment for trees 6.6 inches in 

diameter and larger at 80 years of age is 20 cubic feet per 

acre for ponderosa pine and 40 cubic feet per acre for 

Douglas-fir. However, the typical basal area of stands on this 

unit is about 75 percent that of normal stands, and the total 

yield is correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which makes the use of wheeled and 

tracked equipment difficult. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads 

require suitable surfacing for year-round use. Rock for 

road construction is available in included areas of Rubble 

land and Rock outcrop. 

Seeding establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine seedlings. If seed trees are present, 

natural reforestation of cutover areas by ponderosa pine 

occurs infrequently. The droughtiness of the soil 

increases seedling mortality. 

The common forest understory plants are elk sedge, 

pinegrass, bitterbrush, yarrow, and Oregon-grape. The crown 

density in the areas where the woodland site index was 

measured is 20 percent. This unit is suited to grazing and 

browsing. Seeding to adapted grazable vegetation following 

logging or burning late in summer or in fall generally is most 

successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

149-Sutkin-Rock outcrop complex, 25 to 75 percent 

slopes. This map unit is on mountainsides. Slope is 

dominantly about 50 percent. The native vegetation is 

mainly conifers, grasses, forbs, and shrubs. Elevation is 

2,800 to 4,000 feet. The average annual precipitation is 18 to 

22 inches, the average annual air temperature is about 43 

degrees F, and the average length of the growing season, at 

28 degrees F, is 145 to 170 days. 

This unit is about 55 percent Sutkin stony loam and about 

25 percent Rock outcrop. The components of this unit are 

so intricately intermingled that it was not practical to map 

them separately at the scale used. 

Included in this unit are areas of Sapkin soils and Rubble 

land and concave areas of soils that have slopes of less 

than 25 percent. Included areas make up about 20 percent 

of the total acreage. 

The Sutkin soil is very deep and well drained. It formed in 

residuum and colluvium derived dominantly 

from basalt and containing small amounts of loess. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1/2 inch thick. The 

surface layer is dark brown stony loam about 10 inches 

thick. The subsoil is dark yellowish brown very cobbly loam 

and extremely cobbly loam about 28 inches thick. The 

substratum to a depth of 60 inches or more is dark 

yellowish brown extremely cobbly loam. 

Permeability of the Sutkin soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

Rock outcrop is areas of exposed bedrock. It is on 

hilly to extremely steep mountainsides. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main 

woodland species on the Sutkin soil. On the basis of a 100-

year site curve, the mean site index is 67 for ponderosa pine 

and 81 for Douglas-fir. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 52 cubic feet per acre for ponderosa pine at age 50 

and 71 cubic feet per acre for Douglas-fir at age 40. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 40 cubic feet per acre for 

ponderosa pine and 65 cubic feet per acre for Douglas-fir. 

However, the typical basal area of stands on the Sutkin soil 

is about 70 percent that of normal stands, and the total yield 

is correspondingly lower. 

The main limitations for the harvesting of timber are 

steepness of slope and areas of Rock outcrop, which restrict

the use of wheeled and tracked equipment in skidding 

operations. Cable yarding systems generally are safer, 

and they disturb the soil less. Areas of Rock outcrop and 

Rubble land hinder cable yarding. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads 

require suitable surfacing for year-round use. Rock for 

road construction is readily available on this unit. Avoiding 

areas of Rock outcrop commonly forces yarding and skidding 

paths to converge, which increases the potential for erosion 

and soil compaction. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine seedlings. If seed trees are present, 

natural reforestation of cutover areas by ponderosa pine 

occurs infrequently. The droughtiness of the soil increases 

seedling mortality, especially on south- and southwest-facing 

slopes. The areas of Rock outcrop limit the even distribution 

of reforestation. 

The common forest understory plants are elk sedge, 

pinegrass, bitterbrush, common snowberry, and 

Oregon-grape. The crown density in the areas where the 

woodland site index was measured is 30 percent. The 
Sutkin soil is suited to grazing and browsing. Steepness of 

slope and the areas of Rock outcrop limit access by 

livestock and encourage overgrazing of the less sloping 

areas. The distribution of grazing in the steeply sloping 

areas of this soil can be improved by proper location of salt 

licks, stock watering facilities, and management fences. 

Seeding to adapted grazable vegetation following logging or 

burning late in summer or in fall generally is most 

successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

150-Sutkin Variant stony loam, 0 to 5 percent 

slopes. This very deep, well drained soil is on alluvial fans. It 

formed in loess overlying cobbly or gravelly alluvium. The 

native vegetation is mainly conifers, grasses, forbs, and 

shrubs. Elevation is 2,400 to 2,600 feet. The average annual 

precipitation is 14 to 17 inches, the average annual air 

temperature is about 48 degrees F, and the average length 

of the growing season, at 28 degrees F, is 150 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 1/2 inch thick. The 

surface layer is grayish brown stony loam about 8 inches 

thick. The subsoil is brown gravelly loam and pale brown 

very gravelly loam about 10 inches thick. The substratum to 

a depth of 60 inches or more is pale brown extremely 

gravelly sandy loam. In some areas the part of the soil 

profile below the surface layer is gravelly. 

Included in this unit are small areas of Wenas soils in 

poorly drained, depressional areas and Mippon soils 

near stream channels. Included areas make up about 15 

percent of the total acreage. 

Permeability of this Sutkin Variant soil is moderate. 

Available water capacity is moderate. Effective rooting 

depth is 60 inches or more. Runoff is medium, and the 

hazard of water erosion is slight. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine is the main woodland species on this unit. 

On the basis of a 100-year site curve, the mean site index is 

70 for ponderosa pine. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual 

increment at culmination (CMAI) for trees 0.6 inch in 

diameter and larger at 50 years of age is 55 cubic feet per 

acre. The mean annual increment for trees 6.6 inches in 

diameter and larger at 80 years of age is 45 cubic feet per 

acre. However, the typical basal area of stands on this unit 

is about 60 percent that of normal stands, and the total yield 

is correspondingly lower. 

The main limitation for the harvesting of timber is a 

short period of seasonal soil wetness. The numerous 

stones on the surface of many areas of this unit may 

hinder harvesting. Unsurfaced roads and skid trails 

are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging 

roads require 

suitable surfacing for year-round use. Rock for road 

construction is not readily available on this unit. 

Seedling mortality is the main concern in the production of

timber. Reforestation can be accomplished by planting 

ponderosa pine seedlings. If seed trees are present, natural 

reforestation of cutover areas by ponderosa pine occurs 

periodically. The droughtiness of the soil in this unit 

increases seedling mortality, especially on south- and 

southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, American vetch, common snowberry, and 

ceanothus. The crown density in the areas where the 

woodland site index was measured is 25 percent. This unit 

is well suited to grazing and browsing. Seeding to adapted 

grazable vegetation following logging or burning late in 

summer or in fall generally is most successful. 

This unit is limited for livestock watering ponds and other 

water impoundments because of seepage. Spring 

developments, wells, and pipeline systems can be used to 

provide water for livestock. 

This map unit is in capability subclass Vls, 

nonirrigated. 

151-Taneum loam, 5 to 15 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess overlying weathered sandstone. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation 

is 2,300 to 3,000 feet. The average annual precipitation is 

15 to 18 inches, the average annual air temperature is 

about 48 degrees F, and the average frost-free season is 

120 to 135 days. 

Typically, the surface layer is dark grayish brown and 

grayish brown loam about 14 inches thick. The upper part of 

the subsoil is brown silty clay loam about 13 inches thick, 

and the lower part is brown clay loam about 16 inches thick. 

The upper part of the substratum is yellowish brown loam 

about 7 inches thick, and the lower part to a depth of 60 

inches or more is brown sandy loam. In some areas 

bedrock is at a depth of 40 to 60 inches. 

Included in this unit are areas of Rock Creek, 

McDaniel, and Roza soils. 

Permeability of this Taneum soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Spring grain can be grown during years when 

extra moisture is received. The amount of straw produced by 

spring grain generally is 
not sufficient for erosion control unless it is very carefully 

managed. 

Growing grasses and legumes in the rotation helps to 

control erosion and to maintain or improve tilth. Erosion can 

be reduced by seeding fall grain early, stubble mulching, 

using terraces and diversions, and stripcropping. 

Seeding early in fall, either on the contour or across the 

slope, slows runoff and reduces erosion when the snow 

melts rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and big sagebrush. This unit 

has few limitations for the production of forage. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass and Idaho fescue decreases and 

the proportion of less preferred forage plants such as 

rabbitbrush and big sagebrush increases. Areas that are 

heavily infested with undesirable vegetation can be improved 

by such methods as railing, chaining, beating, plowing, 

chemical treatment, and prescribed burning. Seeding is a 

suitable practice if the range vegetation is in poor condition. 

The unit should be seeded in fall using a drill. Adapted 

grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitations are shrink-swell potential and steepness of slope. 

If buildings are constructed on this unit, properly designing 

foundations and footings and diverting runoff away from 

buildings help to prevent structural damage as a result of 

shrinking and swelling. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitations for the use of septic tank absorption 

fields is the moderately slow permeability. Use of sandy 

backfill for the trench and long absorption lines helps to 

compensate for this limitation. Slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

Lateral seepage can be avoided by installing absorption 

lines on the contour. 

This map unit is in capability subclass Ille, nonirrigated. 

152-Taneum loam, 15 to 30 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess overlying weathered sandstone. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation 

is 2,300 to 3,000 feet. The average annual precipitation is 

15 to 18 inches, the average annual air temperature is 

about 48 degrees F, and the average frost-free season is 

120 to 135 days. 

Typically, the surface layer is dark grayish brown and 

grayish brown loam about 14 inches thick. The upper part of 

the subsoil is brown silty clay loam about 13 inches thick, 

and the lower part is brown clay loam about 16 inches thick. 

The upper part of the substratum is 

yellowish brown loam about 7 inches thick, and the lower 

part to a depth of 60 inches or more is brown sandy loam. In 

some areas bedrock is at a depth of 40 to 60 inches. 

Included in this unit are areas of Rock Creek, 

McDaniel, and Roza soils. 

Permeability of this Taneum soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used for nonirrigated crops, rangeland, 

wildlife habitat, and homesites. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Spring grain can be grown during years when 

extra moisture is received. 

Growing grasses and legumes in the rotation helps to 

control erosion and to maintain or improve tilth. Erosion can 

be reduced by seeding fall grain early, stubble mulching, 

divided-slope farming, and stripcropping. Fall seeding, either 

on the contour or across the slope, slows runoff and reduces 

erosion when the snow melts rapidly while the soil is still 

frozen. Diversions may be needed to intercept runoff from 

higher lying areas. Drop structures are needed in places to 

control the flow of runoff in waterways. Waterways should be 

shaped and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and big sagebrush. This unit has 

few limitations for the production of forage. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass and Idaho fescue decreases and 

the proportion of less preferred forage plants such as 

rabbitbrush and big sagebrush increases. Areas that are 

heavily infested with undesirable vegetation can be 

improved by such methods as railing, chaining, beating, 

plowing, chemical treatment, and prescribed burning. Range 

seeding is a suitable practice if the range vegetation is in 

poor condition. The unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation is steepness of slope. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

steepness of slope and moderately slow permeability. 

Use of sandy backfill for the trench and long absorption 

lines helps to compensate for the moderately slow 

permeability. Slope can cause lateral seepage and 

surfacing of effluent in downslope areas. 

This map unit is in capability subclass IVe, 

nonirrigated. 
153-Taneum loam, 30 to 60 percent slopes. This 

very deep, well drained soil is on uplands. It formed in 

loess overlying weathered sandstone. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 2,300 to 3,000 feet. The average annual 

precipitation is 15 to 18 inches, the average annual air 

temperature is about 48 degrees F, and the average frostfree season is 120 to 135 days. 

Typically, the surface layer is dark grayish brown and 

grayish brown loam about 14 inches thick. The upper part of 

the subsoil is brown silty clay loam about 13 inches thick, 

and the lower part is brown clay loam about 16 inches thick, 

The upper part of the substratum is yellowish brown loam 

about 7 inches thick, and the lower part to a depth of 60 

inches or more is brown sandy loam. In some areas bedrock 

is at a depth of 40 to 60 inches. 

 Included in this unit are areas of Rock Creek, McDaniel, 

and Roza soils and Rock outcrop. 

Permeability of this Taneum soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is very rapid, and the hazard of 

water erosion is very high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and big sagebrush. This unit 

has few limitations for the production of forage. If the range 

is overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass and Idaho fescue decreases and 

the proportion of less preferred forage plants such as 

rabbitbrush and big sagebrush increases. Steepness of 

slope limits access by livestock and promotes overgrazing 

of the less sloping areas. Proper placement of salt licks, 

livestock watering facilities, and fences promotes more 

uniform distribution of grazing. 

Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as chemical 

treatment and prescribed burning. Plant competition can 

be reduced by using chemicals. Range seeding is a suitable 

practice if the range vegetation is in poor condition. Use of 

equipment in some areas is limited by steepness of slope. 

Fall seedings generally are most successful. Adapted 

grasses and legumes should be seeded. 

This map unit is in capability subclass VIle, 

nonirrigated. 

154-Taneum-Rock Creek complex, 5 to 15 percent 

slopes. This map unit is on uplands. The native vegetation 

is mainly grasses, forbs, and shrubs. The elevation is 

2,300 to 3,300 feet. The average annual precipitation is 15 

to 18 inches, the average annual air temperature is about 48 

degrees F, and the average frost-free season is 120 to 135 

days. 

This unit is about 50 percent Taneum loam and about 30 

percent Rock Creek very stony silt loam. The components 

of this unit are so intricately intermingled 

that it was not practical to map them separately at the 

scale used. 

Included with this unit are areas of Clint and McDaniel 

soils. Included areas make up about 20 percent of the total 

acreage. 

The Taneum soil is very deep and well drained. It formed 

in loess overlying weathered sandstone. Typically, the 

surface layer is dark grayish brown and grayish brown loam 

about 14 inches thick. The upper part of the subsoil is brown 

silty clay loam about 13 inches thick, and the lower part is 

brown clay loam about 16 inches thick. The upper part of the 

substratum is yellowish brown loam about 7 inches thick, 

and the lower part to a depth of 60 inches or more is brown 

sandy loam. 

Permeability of the Taneum soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

60 inches or more. Runoff is medium, and the hazard of 

water erosion is moderate. 

The Rock Creek soil is shallow and well drained. It formed 

in loess and residuum derived dominantly from basalt. 

Typically, the surface layer is grayish brown very stony silt 

loam about 2 inches thick. The subsoil is brown very cobbly 

clay about 8 inches thick. Basalt is at a depth of about 10 

inches. Depth to basalt ranges from 8 to 15 inches. In some 

areas the surface layer is stony, and in some areas bedrock 

is at a depth of more than 20 inches. 

Permeability of the Rock Creek soil is moderately slow. 

Available water capacity is low. Effective rooting depth is 

8 to 15 inches. Runoff is medium, and the hazard of 

water erosion is moderate. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation of the Taneum soil is 

mainly bluebunch wheatgrass, Idaho fescue, and big 

sagebrush. This soil has few limitations for the production 

of forage. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less 

preferred forage plants such as rabbitbrush and big 

sagebrush increases. 

The potential native vegetation of the Rock Creek soil is 

mainly stiff sagebrush, Sandberg bluegrass, and eriogonum. 

The main limitations for the production of forage are depth 

to rock and low available water capacity. If the range is 

overgrazed, the proportion of preferred forage plants such 

as stiff sagebrush and Sandberg bluegrass decreases and 

the proportion of less preferred forage plants such as forbs 

and annual grasses increases. 

Areas of the Taneum soil that are heavily infested with 

undesirable vegetation can be improved with such methods 

as chaining, railing, beating, chemical 

treatment, and prescribed burning. Range seeding on the 

Rock Creek soil is not feasible because of the low available 

water capacity and depth to rock. Range seeding on the 

Taneum soil is a suitable practice if the 
range vegetation is in poor condition. The soil should be 

seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This map unit is in capability subclass VIs, 

nonirrigated. 

155-Tekison stony loam, 0 to 25 percent slopes. This 

very deep, well drained soil is on ridges and benches. It 

formed in residuum and colluvium derived from basalt and 

containing small amounts of loess. The native vegetation is 

mainly conifers, grasses, and shrubs. Elevation is 2,800 to 

3,600 feet. The average annual precipitation is 16 to 20 

inches, the average annual temperature is about 47 degrees 

F, and the average length of the growing season, at 28 

degrees F, is 150 to 170 days. 

Typically, the surface layer is brown stony loam about 4 

inches thick. The upper part of the subsoil is brown stony 

loam about 8 inches thick, the next part is brown very 

cobbly clay loam about 8 inches thick, and the lower part to 

a depth of 60 inches or more is yellowish brown very 

gravelly clay and very cobbly clay. 

Included in this unit are small areas of Meystre, Odo, 

and Rock Creek soils and areas of Tekison soils that have 

slopes of more than 25 percent. 

Permeability of this Tekison soil is slow. Available water 

capacity is moderate. Effective rooting depth is 60 inches or 

more. Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Ponderosa pine and Douglas-fir are the main 

woodland species on this unit. On the basis of a 100-year 

site curve, the mean site index is 69 for ponderosa pine and 

80 for Douglas-fir. Yield tables for normal, even-aged, 

unmanaged stands indicate that the mean annual increment 

at culmination (CMAI) for trees 0.6 inch in diameter and 

larger is 54 cubic feet per acre for ponderosa pine at age 55 

and 69 cubic feet per acre for Douglas-fir at age 40. The 

mean annual increment for trees 6.6 inches in diameter and 

larger at 80 years of age is 44 cubic feet per acre for 

ponderosa pine and 56 cubic feet per acre for Douglas-fir. 

However, the typical basal area of stands on this unit is 

about 95 percent that of normal stands, and the total yield is 

correspondingly lower. 

The main limitation for the harvesting of timber is a short 

period of seasonal soil wetness. Unsurfaced roads and skid 

trails are slippery when wet, and they may be impassable 

during spring runoff or in rainy periods. Logging roads 

require suitable surfacing for year-round use. Rock for 

road construction is not readily available on this unit. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting ponderosa pine seedlings. If seed trees are 

present, natural reforestation of cutover areas by 

ponderosa pine occurs infrequently. The droughtiness of the 

soil increases seedling mortality, especially on south- and

southwest-facing slopes. 

The common forest understory plants are elk sedge, 

pinegrass, western yarrow, and bitterbrush. The crown 

density in the areas where the woodland site index was 

measured is 25 percent. This unit is well suited to grazing 

and browsing. Seeding to adapted grazable vegetation 

following logging or burning late in summer or in fall 

generally is most successful. 

This map unit is in capability subclass VIs, 

nonirrigated. 

156-Tieton fine sandy loam, 2 to 5 percent slopes. 

This deep, well drained soil is on uplands. It formed in 

loess and in material derived from andesite. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation 

is 1.500 to 2,300 feet. The average annual precipitation is 

11 to 15 inches, the average annual air temperature is 

about 50 degrees F, and the average frost-free season is 

135 to 150 days. 

Typically, the surface layer is grayish brown fine sandy 

loam about 9 inches thick. The upper part of the subsoil is 

brown loam about 6 inches thick, and the lower part is 

yellowish brown and brown silty clay loam and clay loam 

about 29 inches thick. The substratum is grayish brown loam 

about 4 inches thick. Andesite is at a depth of about 48 

inches. Depth to andesite ranges from 40 to 60 inches. In 

some areas the surface layer is loam or stony loam. In some 

areas sandstone is at a depth of 40 to 60 inches, and in 

some areas andesite is at a depth of more than 60 inches. 

Included in this unit are areas of Simcoe and Rock Creek 

soils and Rock outcrop. Also included are areas of soils that 

have a high water table. 

Permeability of this Tieton soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 40 

to 60 inches. Runoff is slow, and the hazard of water erosion 

is slight. The hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain and tree fruit. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are the hazards of 

soil blowing and water erosion. Furrow, corrugation, and 

sprinkler irrigation systems are suited to the soil in this unit. 

The type of irrigation system used depends on the kind of 

crop grown. If furrow and corrugation irrigation systems are 

used, runs should be on the contour or across the slope. The 

hazard of water erosion can be minimized by keeping runs 

short. Use of sprinkler or drip irrigation permits the even, 

controlled application of water, reduces runoff, and minimizes 

the risk of erosion. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. Pipe, ditch 
lining, or drop structures should be installed in irrigation 

ditches to facilitate irrigation and prevent excessive ditch 

erosion. 

Using a cropping system that includes close-growing, highresidue crops in the rotation, maintaining crop residue on the 

surface, and using minimum tillage reduce erosion. Return of 

crop residue to the soil also helps to maintain or improve the 

organic matter content and to maintain tilth. A plowpan 

develops in this soil from excessive tillage with heavy 

equipment. Growing annual cover crops in orchards and 

vineyards reduces erosion. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitations are depth to rock and shrink-swell potential. 

Bedrock hinders excavation. If buildings are constructed on 

the soil in this unit, properly designing foundations and 

footings and diverting runoff away from buildings help to 

prevent structural damage as a result of shrinking and 

swelling. Soil blowing can be a problem during construction 

on large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

the moderately slow permeability. Use of sandy backfill for 

the trench and long absorption lines helps to compensate 

for this limitation. 

This map unit is in capability subclass lIe, irrigated. 

157-Tieton loam, 0 to 2 percent slopes. This deep, 

well drained soil is on uplands. It formed in loess and in 

material derived from andesite. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,500 to 

2,300 feet. The average annual precipitation is 11 to 15 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typically, the surface layer is grayish brown loam 

about 9 inches thick. The upper part of the subsoil is brown 

loam about 6 inches thick, and the lower part is yellowish 

brown and brown silty clay loam and clay loam about 29 

inches thick. The substratum is grayish brown loam about 4 

inches thick. Andesite is at a depth of about 48 inches. Depth 

to andesite ranges from 40 to 60 inches. In some areas the 

surface layer is stony, and in some areas sandstone is at a 

depth of 40 to 60 inches. 

Included in this unit are small areas of Simcoe, Rock 

Creek, and Ritzville soils and Rock outcrop. Also included 

are areas of soils that have a seasonal high water table. 

Permeability of this Tieton soil is moderately slow. Available 

water holding capacity is high. Effective rooting depth is 40 

to 60 inches. Runoff is slow, and the hazard of water 

erosion is slight. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated 

crops are grain and tree fruit. Grasses and legumes are 

grown for hay, pasture, and seed. 

This unit has few limitations for irrigated crops. Furrow, 

corrugation, drip, and sprinkler irrigation systems are suited to 

the soil in this unit. The type of system used depends on the 

kind of crop grown. Use of sprinkler or drip irrigation permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should also be adjusted to the available water 

capacity and the crop needs. Pipe, ditch lining, or drop 

structures should be installed in irrigation ditches to facilitate 

irrigation and prevent excessive ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or increase the organic matter content, 

help to maintain tilth, and increase the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue on 

the surface reduce water erosion. Use of cover crops 

reduces erosion in orchards and vineyards. A plowpan 

develops in this soil, but it can be broken by chiseling or 

subsoiling when the soil is dry. Using vegetated filter strips at 

the end of rows or using sediment ponds, or both, reduces 

the volume of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitations for homesites are depth to rock and shrinkswell potential. The bedrock hinders excavation. If buildings 

are constructed on the soil in this unit, properly designing 

foundations and footings and diverting runoff away from 

buildings help to prevent structural damage as a result of 

shrinking and swelling. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

moderately slow permeability. Use of sandy backfill for the 

trench and long absorption lines helps to compensate for 

this limitation. 

This map unit is in capability class I, irrigated. 

158-Tieton loam, 2 to 5 percent slopes. This deep, 

well drained soil is on uplands. It formed in loess and in 

material derived from andesite. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,500 to 2,300 

feet. The average annual precipitation is 11 to 15 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 150 days. 

Typically, the surface layer is grayish brown loam about 9 

inches thick. The upper part of the subsoil is brown loam 

about 6 inches thick, and the lower part is yellowish brown 

and brown silty clay loam and clay loam about 29 inches 

thick. The substratum is grayish brown loam about 4 inches 

thick. Andesite is at a depth of about 48 inches. Depth to 

andesite ranges from 40 to 60 
inches. In some areas the surface layer is fine sandy loam 

or is stony, and in some small areas sandstone is at a 

depth of 40 to 60 inches. 

Included in this unit-are areas of Simcoe, Rock Creek, and 

Ritzville soils, Rock outcrop, and soils that have a seasonal 

high water table. 

Permeability of this Tieton soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

40 to 60 inches. Runoff is slow, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are grain and tree fruit. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of 

water erosion. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. If furrow 

or corrugation irrigation systems are used, runs should be on 

the contour or across the slope. The risk of erosion can be 

minimized by keeping the runs short. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water 

infiltration rate; however, the fine soil particles dislodged 

during cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Pipe, ditch lining, or drop structures should be installed in 

irrigation ditches to facilitate irrigation and prevent excessive 

ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation and maintaining 

crop residue on the surface reduce water erosion. Use 

of annual or perennial cover crops during the irrigation 

season reduces erosion in orchards and vineyards. A 

plowpan develops in this soil, but it can be broken by 

chiseling or subsoiling when the soil is dry. Using vegetated 

filter strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitations are depth to rock and shrink-swell 

potential. The bedrock hinders excavation. If 

buildings are constructed on the soil in this unit, properly 

designing foundations and footings and diverting runoff 

away from buildings help to prevent structural damage as a 

result of shrinking and swelling. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is the 

moderately slow permeability. Use of sandy backfill for the 

trench and long absorption lines helps to compensate for 

this limitation. 

This map unit is in capability subclass Ile, irrigated. 

159-Tieton loam, 5 to 8 percent slopes. This deep, 

well drained soil is on uplands. It formed in loess and in 

material derived from andesite. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,500 to 2,300 

feet. The average annual precipitation is 11 to 15 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 135 to 150 days. 

Typically, the surface layer is grayish brown loam about 9 

inches thick. The upper part of the subsoil is brown loam 

about 6 inches thick, and the lower part is yellowish brown 

and brown silty clay loam and clay loam about 29 inches 

thick. The substratum is grayish brown loam about 4 inches 

thick. Andesite is at a depth of about 48 inches. Depth to 

andesite ranges from 40 to 60 inches. In some areas the 

surface layer is fine sandy loam, and in a few small areas 

sandstone is at a depth of 40 to 60 inches. 

Included in this unit are areas of Simcoe, Rock Creek, and 

Ritzville soils, areas of Rock outcrop, and areas of soils that 

have a seasonal high water table. 

Permeability of this Tieton soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

40 to 60 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops 

(fig. 5), for wildlife habitat, and as homesites. The main 

irrigated crops are grain and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. The type 

system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk of 

erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs.

Use of minimum tillage and return of crop residue to 
Figure 5.-Orchard on Tieton loam, 5 to 8 percent slopes, in the center. Wind machines in the orchard reduce the hazard of frost. 

the soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes closegrowing, high-residue crops in the rotation reduces water 

erosion. Growing cover crops helps to control erosion in 

orchards and vineyards. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitations are depth to rock and shrink-swell potential. 

The bedrock hinders excavation. If building are constructed 

on the soil in this unit, properly designing foundations and 

footings and diverting runoff away from buildings help to 

prevent structural damage as a result of shrinking and 

swelling. Dustiness can be a problem during construction on 

large building sites; therefore, these sites should be 

disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

moderately slow permeability. Use of sandy backfill 

for the trench and long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclass IIIe, irrigated. 

160-Tieton loam, 8 to 15 percent slopes. This deep, 

well drained soil is on uplands. It formed in loess and in 

material derived from andesite. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,500 to 

2,300 feet. The average annual precipitation is 11 to 15 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typically, the surface layer is grayish brown loam about 9 

inches thick. The upper part of the subsoil is brown loam 

about 6 inches thick, and the lower part is yellowish brown 

and brown silty clay loam and clay loam about 29 inches 

thick. The substratum is grayish brown loam about 4 inches 

thick. Andesite is at a depth of about 48 inches. Depth to 

andesite ranges from 40 to 60 
inches. In some areas sandstone is at a depth of 40 to 60 

inches. 

Included in this unit are areas of Simcoe, Rock Creek, and 

Ritzville soils, areas of Rock outcrop, small areas of soils 

that have a seasonal high water table, and areas of Tieton 

soils that have slopes of less than 8 percent. 

Permeability of this Tieton soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 40 

to 60 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain and tree 

fruit. Grasses and legumes are grown for hay, 

pasture, and seed. A cover crop is grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should 

also be adjusted to the available water capacity and the 

crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. Use 

of annual or perennial cover crops reduces erosion in 

orchards. A plowpan develops in this soil; however, it can be 

broken by chiseling or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are the hazard 

of water erosion and low annual precipitation. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain early, 

stubble mulching, using terraces and diversions, and 

stripcropping. Seeding early in fall, either on the contour or 

across the slope, slows runoff and reduces erosion when the 

snow melts rapidly while the soil is still frozen. Drop 

structures are needed in places to control the flow of runoff 

in waterways. Waterways should be shaped and seeded 

to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and big sagebrush. If the 

range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass and Idaho fescue 

decreases and the proportion of less preferred forage plants 

such as rabbitbrush and big sagebrush increases. Areas 

that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, chemical treatment, and prescribed burning. 

Range seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be 

seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations are steepness of slope, depth to rock, and 

shrink-swell potential. The bedrock hinders excavation. If 

buildings are constructed on the soil in this unit, properly 

designing foundations and footings and diverting runoff away 

from buildings help to prevent structural damage as a result of 

shrinking and swelling. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is the 

moderately slow permeability. Use of sandy backfill for the 

trench and long absorption lines helps to compensate for 

this limitation. Slope can cause lateral seepage and 

surfacing of effluent in downslope areas. Lateral seepage 

can be reduced by installing absorption lines on the contour. 

This map unit is in capability subclasses IVe, irrigated, and 

Ille, nonirrigated. 

161-Tieton loam, 15 to 30 percent slopes. This 

deep, well drained soil is on uplands. It formed in loess and 

in material derived from andesite. The native vegetation is 

mainly grasses, forbs, and shrubs. Elevation is 1,500 to 

2,300 feet. The average annual precipitation is 11 to 15 

inches, the average annual air temperature is about 48 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typically, the surface layer is grayish brown loam about 9 

inches thick. The upper part of the subsoil is brown loam 

about 6 inches thick, and the lower part is yellowish brown 

and brown silty clay loam and clay loam about 29 inches 

thick. The substratum is grayish brown loam about 4 inches 

thick. Andesite is at a depth of about 48 inches. Depth to 

andesite ranges from 40 to 60 inches. In some areas 

sandstone is at a depth of 40 to 60 inches. 

Included in this unit are areas of Simcoe, Rock Creek, and 

Ritzville soils and Rock outcrop. 

Permeability of this Tieton soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

40 to 60 inches. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, wildlife habitat, rangeland and homesites. 

The main irrigated crops are grain and tree fruit. Grass and 

legumes are grown for hay, pasture, and seed. A cover crop 

is grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of 
irrigation water should also be adjusted to the available 

water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. 

Growing perennial cover crops reduces erosion in 

orchards and vineyards. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is 

most suitable. Erosion can be reduced by seeding fall 

grain early, stubble mulching, divided-slope farming, and 

stripcropping. Seeding in fall, either on the contour or across 

the slope, slows runoff and reduces erosion when the snow 

melts rapidly while the soil is still frozen. Drop structures 

are needed in places to control the flow of runoff in 

waterways. Waterways should be shaped and seeded to 

perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Idaho fescue, and big sagebrush. If the 

range is overgrazed, the proportion of preferred forage plants 

such as bluebunch wheatgrass and Idaho fescue decreases 

and the proportion of less preferred forage plants such as 

rabbitbrush and big sagebrush increases. Areas that are 

heavily infested with undesirable vegetation can be 

improved by such methods as railing, chaining, plowing, 

beating, chemical treatment, and prescribed burning. 

Range seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. 

This unit is poorly suited to homesite development. The 

main limitation is steepness of slope. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

steepness of slope and the moderately slow permeability. 

Use of long absorption lines and sandy backfill for the 

trench helps to compensate for the moderately slow 

permeability. Slope can cause lateral seepage and 

surfacing of effluent in downslope areas. 

This map unit is in capability subclasses IVe, 

irrigated and nonirrigated. 

162-Tieton-Rock outcrop complex, 0 to 30 percent 

slopes. This map unit is on uplands (fig. 6). The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 1,500 to 2,300 feet. The average annual 

precipitation is 11 to 15 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 150 days. 

This unit is about 60 percent Tieton loam and about 25 

percent Rock outcrop. The components of this unit are so 

intricately intermingled that it was not practical to map them 

separately at the scale used. 

Included in this unit are areas of Ritzville and Simcoe 

soils. Included areas make up about 15 percent of the total 

acreage. 

The Tieton soil is deep and well drained. It formed in 

loess and in material derived from andesite. Typically, the 

surface layer is grayish brown loam about 9 inches thick. 

The upper part of the subsoil is brown loam about 6 inches 

thick, and the lower part is yellowish brown and brown silty 

clay loam and clay loam about 29 inches thick. The 

substratum is grayish brown loam about 4 inches thick. 

Andesite is at a depth of about 48 inches. Depth to andesite 

ranges from 40 to 60 inches. In some areas sandstone is at 

a depth of 40 to 60 inches, and in some areas andesite or 

sandstone is at a depth of more than 60 inches. 

Permeability of the Tieton soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

40 to 60 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

Rock outcrop is areas of exposed bedrock. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation on the Tieton soil is 

mainly bluebunch wheatgrass, Idaho fescue, and big 

sagebrush. If the range is overgrazed, the proportion of 

preferred forage plants such as bluebunch wheatgrass and 

Idaho fescue decreases and the proportion of less preferred 

forage plants such as rabbitbrush and big sagebrush 

increases. Areas that are heavily infested with undesirable 

vegetation can be improved by such methods as chemical 

treatment and prescribed burning. Because the areas of the 

Tieton soil are not large enough to effectively seed using a 

drill, proper range use, deterred grazing, and rotation 

grazing are the most effective methods of range 

management and erosion control. Fences are needed in 

most areas to prevent cattle from grazing in adjacent 

orchards. 

This map unit is in capability subclass VIs, nonirrigated. 

163-Toppenish silt loam. This very deep, artificially 

drained soil is on flood plains. It formed in alluvium. Slope is 

0 to 2 percent. The native vegetation is water-tolerant 

grasses and deciduous trees. Elevation is 700 to 1,800 feet. 

The average annual precipitation is 8 to 10 inches, the 

average annual air temperature is about 51 degrees F, and 

the average frost-free season is 130 to 180 days. 

Typically, the surface layer is dark grayish brown, 

strongly alkaline silt loam about 4 inches thick. The 

upper part of the subsoil is gray, strongly alkaline silty 

clay loam about 10 inches thick, and the lower part is 
Figure 6.-Typical area of Tieton-Rock outcrop complex, 0 to 30 percent slopes. Grasses and orchard are on Tieton 

soils in foreground. 

gleyed, dark grayish brown and brown, moderately alkaline 

and mildly alkaline silt loam about 36 inches thick. The 

substratum to a depth of 60 inches or more is brown, mildly 

alkaline extremely gravelly sand. In some areas the surface 

layer is silty clay loam. 

Included in this unit are small areas of Wenas, Track, 

Kittitas, Fiander, Esquatzel, and Naches soils and areas of

Toppenish soils that have not been artificially drained. 

Permeability of this Toppenish soil is moderately slow to 

the substratum and very rapid through it. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 24 to 48 

inches from June to November. Runoff is very slow, and the 

hazard of water erosion is slight. This unit is subject to rare 

periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. Where areas of this unit are drained, the 

main irrigated crops are asparagus, corn, grain, and 

peas. Grasses and legumes are grown for hay and 

pasture. 

The main limitation for irrigated crops is wetness. Deeprooted crops are suited to areas where a drainage system 

has been installed and is maintained. Dikes are effective in 

diverting floodwater and they need to be maintained to 

provide continuing protection from flooding. If drainage 

systems are not maintained, the soil in this unit has a high 

water table during the irrigation season. 

Furrow, corrugation, drip, and sprinkler irrigation systems 

are suited to the soil in this unit. The type of irrigation 

system used depends on the kind of crop grown. If surface 

systems are used, the risk of erosion can be minimized by 

keeping runs short. Use of sprinkler and drip irrigation 

systems permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. To avoid 

loss of water and leaching of plant nutrients from 

overirrigation, applications of 
irrigation water should also be adjusted to the available 

water capacity and the crop needs. 

Proper timing of minimum tillage and return of crop 

residue to the soil help to avoid soil compaction, help to 

maintain or improve the organic matter content, help to 

maintain tilth, and improve the water infiltration rate. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation and maintaining crop residue on the 

surface reduce water erosion. Using vegetated filter strips at 

the end of rows or using sediment ponds, or both, reduces 

the volume of sediment in the tailwater. A plowpan develops 

in this soil; however, it can be broken by chiseling or 

subsoiling when the soil is dry. 

Where the soil in this unit is not adequately drained, the 

main limitations for use as homesites are the hazard of 

flooding and wetness. Dikes and channels that have outlets 

to bypass floodwater can be used to protect buildings. 

Wetness can be reduced by installing drain tile around 

footings. Dustiness can be a problem during construction on 

large building sites; therefore, these sites should be 

disturbed as little as possible. Ground cover that is adapted 

to alkaline soil should be used. 

The main limitations for septic tank absorption fields 

are wetness and the moderately slow permeability. 

Moderately slow permeability and the seasonal high water 

table increase the possibility of failure of septic tank 

absorption fields. 

This map unit is in capability subclass Illw, irrigated. 

164-Torriorthents, steep. These shallow and moderately 

deep, well drained soils are on uplands. They formed in 

material derived from mixed sources and containing a small 

amount of loess. Slope is 30 to 60 percent. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

1,600 to 2,000 feet. The average annual precipitation is 8 to 

12 inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 160 

days. 

No single profile is typical of Torriorthents, but one 

commonly observed in the survey area has a surface layer 

of brown gravelly sandy loam about 4 inches thick. The 

underlying material is light brownish gray very gravelly 

sandy loam and gravelly sand about 27 inches thick. Soft, 

tuffaceous sandstone is at a depth of about 31 inches. 

Depth to sandstone, old gravelly alluvium, or lake sediment 

ranges from 10 to 40 inches. Texture of these soils varies 

widely within short distances. In some areas the surface 

layer is very gravelly. 

Included in this unit are Roza, Harwood, Gorst, and 

Cowiche soils and areas of Rock outcrop. 

Permeability of Torriorthents is rapid to the sandstone and 

slow through it. Available water capacity ranges from low to 

high. Effective rooting depth is 10 to 40 inches. Runoff is very 

rapid, and the hazard of water erosion is very high. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, and big sagebrush. 

The main limitation for the production of forage is low 

available water capacity. If the range is overgrazed, the 

proportion of preferred forage plants such as bluebunch 

wheatgrass decreases and the proportion of less preferred 

forage plants such as big sagebrush and rabbitbrush 

increases. Brush control is limited to aerial chemical 

applications and prescribed burning because of the 

steepness of slope and hazard of water erosion. Seeding is 

not feasible because of the low available water capacity. 

Steepness of slope limits access by livestock and promotes 

overgrazing of the less sloping areas. Proper location of salt 

licks, stock water, and fences promotes more uniform 

distribution of grazing. Other management practices suitable 

for use on this unit are proper range use, deferred grazing, 

and rotation grazing. 

This map unit is in capability subclass VIle, 

nonirrigated. 

165-Track loam. This very deep, artificially drained soil 

is on flood plains. It formed in mixed alluvium. Slope is 0 to 

2 percent. The native vegetation is water-tolerant grasses 

and forbs. Elevation is 800 to 1,500 feet. The average 

annual precipitation is 8 to 10 inches, the average annual 

air temperature is about 51 degrees F, and the average 

frost-free season is 130 to 180 days. 

Typically, the surface layer is dark grayish brown, strongly 

alkaline loam about 14 inches thick. The upper part of the 

subsoil is grayish brown, strongly alkaline very gravelly loam 

about 7 inches thick, and the lower part is brown, strongly 

alkaline very gravelly loam about 5 inches thick. The 

substratum to a depth of 60 inches or more is brown, 

moderately alkaline very gravelly loamy sand. In some areas 

the surface layer is silty clay loam or very gravelly loam. 

Included in this unit are areas of Ashue, Toppenish, 

Weirman, and Zillah soils. Also included are areas of saltand alkali-affected soils, ponded soils, and Track soils 

that have not been artificially drained or have slopes of 

more than 2 percent. 

Permeability of this Track soil is moderately slow. 

Available water capacity is moderate. Effective rooting depth 

is limited by a seasonal high water table that is at a depth 

of 24 to 48 inches from June to November. Runoff is very 

slow, and the hazard of water erosion is slight. This soil is 

subject to rare periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are asparagus, 

corn, grain, and peas. Grasses and legumes are grown 

for hay and pasture. 

The main limitations for irrigated crops are wetness and 

low available water capacity. Deep-rooted crops are suited 

to areas where a drainage system has been installed and 

maintained. Dikes are effective in diverting floodwater, but 

they need to be maintained to provide 
continuing protection from flooding. If drainage systems are 

not maintained, the soil in this unit has a high water table 

during the irrigation season. 

Furrow, corrugation, drip, and sprinkler irrigation systems 

are suited to the soil in this unit. The type of irrigation system 

used depends on the kind of crop grown. If surface irrigation 

is used, the risk of erosion can be minimized by keeping runs 

short. Use of sprinkler or drip irrigation permits the even, 

controlled application of water, reduces runoff, and minimizes 

the risk of erosion. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to avoid compaction, to maintain or improve the 

organic matter content, to maintain tilth, and to improve the 

water infiltration rate. Using a cropping system that 

includes close-growing, high-residue crops in the rotation 

and maintaining crop residue on the surface reduce water 

erosion. Using vegetated filter strips at the end of rows or 

using sediment ponds, or both, reduces the volume of 

sediment in the tailwater. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when the 

soil is dry. Exposing the very gravelly subsoil during 

leveling should be avoided. Shallow cuts are feasible in 

some areas. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and wetness. 

Dikes and channels that have outlets to bypass floodwater 

can be used to protect buildings from flooding. Wetness can 

be reduced by installing drain tile around footings. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

wetness and seepage. The seasonal high water table can 

increase the possibility of the failure of absorption fields. 

Care should be taken to prevent the contamination of 

water supplies as a result of seepage. 

This map unit is in capability subclass Illw, irrigated. 

166-Tumac very stony sandy loam, 5 to 45 percent 

slopes. This very deep, well drained soil is on south-facing 

side slopes of uplands and mountains. It formed in 

colluvium derived from basalt and andesite and containing 

volcanic ash. The native vegetation is mainly conifers, 

grasses, forbs, and shrubs. Elevation is 4,100 to 5,200 

feet. The average annual precipitation is 30 to 60 inches, 

the average annual air temperature is about 43 degrees F, 

and the average length of the growing season, at 28 

degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

upper part of the surface layer is brown very stony sandy 

loam about 4 inches thick, and the lower part is brown very 

gravelly loam about 11 inches thick. The upper part 

of the subsoil is yellowish brown very gravelly loam about 

15 inches thick, and the lower part to a depth of 60 inches 

or more is yellowish brown and strong brown extremely 

gravelly loam. In some areas the subsoil is gravelly loam. 

Included in this unit are areas of Tumac soils that have 

slopes of 45 to 60 percent and poorly drained soils in small 

depressional areas. 

Permeability of this Tumac soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Lodgepole pine, grand fir, and Douglas-fir are the main 

woodland species on the soil in this unit. Among the trees of 

limited extent are ponderosa pine, western larch, 

Engelmann spruce and subalpine fir. On the basis of 

100-year site curve, the mean site index is 88 for Douglasfir, 87 for grand fir, 90 for lodgepole pine, and 73 for 

ponderosa pine. Yield tables for normal, even-aged, 

unmanaged stands of Douglas-fir indicate that the mean 

annual increment at culmination (CMAI) for trees 0.6 inch in 

diameter and larger at 40 years of age is 82 cubic feet per 

acre. The mean annual increment for Douglas-fir trees 6.6 

inches in diameter and larger at 80 years of age is 70 cubic 

feet per acre. The mean annual increment at culmination for 

lodgepole pine at 100 years of age is about 100 cubic feet 

per acre. However, the typical basal area of stands on this 

unit is about 85 percent that of normal stands, and the total 

yield is correspondingly lower. 

The main limitation for the harvesting of timber is the 

difficulty of using wheeled and tracked equipment where 

slopes are more than 30 percent. Use of wheeled and 

tracked equipment when the soil is moist can produce ruts, 

compact the soil, and damage tree roots. Unsurfaced roads 

and skid trails are soft and slippery when wet, and they may 

be impassable during spring runoff or in rainy periods. 

Logging roads require suitable surfacing for year-round use. 

Rock for road construction is not readily available on this 

unit. Steep skid trails and firebreaks are subject to rilling and 

gullying unless adequate water bars are provided or they 

are protected by plant cover. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting Douglas-fir and ponderosa pine seedlings. If 

seed trees are present, natural reforestation of cutover areas 

by grand fir and lodgepole pine occurs readily. This can 

delay establishment of planted seedlings. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, pachystima, and Oregon-grape. The 

crown density in the areas where the woodland site index 

was measured is 25 percent. This unit is well suited to 

grazing and browsing. Seeding to adapted 
grazable vegetation following logging or burning late in 

summer or in fall generally is most successful. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

167-Tumac very stony sandy loam, 45 to 65 percent 

slopes. This very deep, well drained soil is on south-facing 

mountainsides. It formed in colluvium derived from basalt 

and andesite and containing volcanic ash. The native 

vegetation is mainly conifers, grasses, forbs, and shrubs. 

Elevation is 4,100 to 5,200 feet. The average annual 

precipitation is 30 to 60 inches, the average annual air 

temperature is about 43 degrees F, and the average length 

of the growing season, at 28 degrees F, is 145 to 170 days. 

Typically, the surface is covered with a mat of partially 

decomposed organic material about 2 inches thick. The 

upper part of the surface layer is brown very stony sandy 

loam about 4 inches thick, and the lower part is brown very 

gravelly loam about 11 inches thick. The upper part of the 

subsoil is yellowish brown very gravelly loam about 15 

inches thick, and the lower part to a depth of 60 inches or 

more is yellowish brown and strong brown extremely gravelly

loam. In some areas the subsoil is gravelly loam. 

Included in this unit is about 10 percent Rock outcrop and 

Rubble land. Also included are areas of Tumac soils that 

have slopes of less than 45 percent. 

Permeability of this Tumac soil is moderate. Available 

water capacity is moderate. Effective rooting depth is 60 

inches or more. Runoff is rapid, and the hazard of water 

erosion is high. 

This unit is used as grazable woodland and for wildlife 

habitat. 

Lodgepole pine, grand fir, and Douglas-fir are the main 

woodland species on the soil in this unit. Among the trees of 

limited extent are ponderosa pine, western larch, Engelmann 

spruce, and subalpine fir. On the basis of a 100-year site 

curve, the mean site index is 88 for Douglas-fir, 87 for grand 

fir, 90 for lodgepole pine, and 73 for ponderosa pine. Yield 

tables for normal, even-aged, unmanaged stands of 

Douglas-fir indicate that the mean annual increment at 

culmination (CMAI) for trees 0.6 inch in diameter and larger 

at 40 years of age is 82 cubic feet per acre. The mean 

annual increment for Douglas-fir trees 6.6 inches in diameter 

and larger at 80 years of age is 70 cubic feet per acre. The 

mean annual increment at culmination is about 100 cubic 

feet per acre for lodgepole pine at 100 years of age. 

However, the typical basal area of stands on this unit is 

about 85 percent that of normal stands, and the total yield is 

correspondingly lower. 

The main limitation for the harvesting of timber is 

steepness of slope, which restricts the use of wheeled and 

tracked equipment in skidding operations. Cable 

yarding systems generally are safer, and they disturb the soil 

less. Use of wheeled and tracked equipment when 

the soil is moist can produce ruts, compact the soil, and 

damage tree roots. Unsurfaced roads and skid trails are soft 

and slippery when wet, and they may be impassable during 

spring runoff or in rainy periods. Logging roads require 

suitable surfacing for year-round use. Rock for road 

construction is available in the included areas of Rock 

outcrop and Rubble land. Steep yarding paths, skid trails, 

and firebreaks are subject to rilling and gullying unless 

adequate water bars are provided or they are protected by 

plant cover. 

Seedling establishment is the main concern in the 

production of timber. Reforestation can be accomplished by 

planting Douglas-fir and ponderosa pine seedlings. If seed 

trees are present, natural reforestation of cutover areas by 

grand fir and lodgepole pine occurs readily. This can delay 

establishment of planted seedlings. 

The common forest understory plants are elk sedge, 

pinegrass, lupine, pachystima, and Oregon-grape. The 

crown density in the areas where the woodland site index 

was measured is 25 percent. This unit is suited to 

browsing. The main limitation for the production of forage is 

steepness of slope, which limits access by livestock. 

Seeding to adapted grazable vegetation following logging 

or burning late in summer or in fall generally is most 

successful. Because of the steepness of slope, broadcast 

seeding should be used. 

This map unit is in capability subclass Vlls, 

nonirrigated. 

168-Umapine silt loam, 0 to 5 percent slopes. This 

very deep, somewhat poorly drained, salt- and alkali-affected 

soil is on flood plains and low terraces. It formed in alluvium. 

The native vegetation is mainly salt- and alkali-tolerant 

grasses, forbs, and shrubs. Elevation is 650 to 900 feet. The 

average annual precipitation is 6 to 9 inches, the average 

annual air temperature is about 50 degrees F, and the 

average frost-free season is 130 to 180 days. 

Typically, the surface layer is light brownish gray, very 

strongly alkaline silt loam about 7 inches thick. The 

underlying material to a depth of 60 inches or more is light 

brownish gray and light gray, very strongly alkaline and 

strongly alkaline silt loam. In some areas the surface layer is 

dark gray. 

Included in this unit are areas of Esquatzel, Toppenish, 

and Warden soils. Also included are areas of soils that are 

underlain by a hardpan at a depth of 20 to 40 inches. 

Permeability of this Umapine soil is moderate. Available 

water capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 12 to 42 

inches from November to June. Runoff is very slow, and the 

hazard of water erosion is slight. The soil is subject to 

occasional periods of flooding in spring. 

This unit is used as rangeland and for wildlife habitat. 
The potential native vegetation is mainly basin wildrye, 

inland saltgrass, and black greasewood. The main limitations 

for the production of forage are seasonal soil wetness and 

the alkalinity of the soil. If the range is overgrazed, the 

proportion of preferred forage plants such as basin wildrye 

decreases and the proportion of less preferred forage plants 

such as inland saltgrass and quackgrass increases. Areas 

that are heavily infested with undesirable vegetation can 

be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition. The unit should be seeded in 

fall using a drill. Grasses adapted to the alkaline condition of 

the soil should be seeded. 

This map unit is in capability subclass VIw, 

nonirrigated. 

169-Umapine silt loam, drained, 0 to 2 percent 

slopes. This very deep, artificially drained, salt- and alkaliaffected soil is on flood plains and low terraces. It formed in 

alluvium. The native vegetation is mainly salt- and alkalitolerant grasses, forbs, and shrubs. Elevation is 650 to 

900 feet. The average annual precipitation is 6 to 9 inches, 

the average annual air temperature is about 50 degrees F, 

and the average frost-free season is 130 to 180 days. 

Typically, the surface layer is light brownish gray, 

very strongly alkaline silt loam about 7 inches thick. The 

underlying material to a depth of 60 inches or more is light 

brownish gray and light gray, very strongly alkaline and 

strongly alkaline silt loam. In some areas the surface layer is 

dark gray. 

Included in this unit are areas of Esquatzel, Toppenish, 

Kittitas, and Warden soils. Also included are areas of soils 

that are underlain by a hardpan at a depth of 20 to 40 

inches and areas of Umapine soils that have not been 

artificially drained. 

Permeability of this Umapine soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. A seasonal high water table is at a depth of 24 to 48 

inches from November to June. Runoff is very slow, and the 

hazard of water erosion is slight. The soil is subject to rare 

periods of flooding. 

This unit is used for irrigated crops, wildlife habitat, and 

homesites. The main irrigated crops are asparagus, 

corn, hops, grain, and peas. Grasses and legumes are 

grown for hay, pasture, and seed. 

The main limitations for irrigated crops are wetness, 

alkalinity, and the hazard of water erosion. Reclamation of 

the soil in this unit may require the addition of such 

amendments as gypsum, sulfur, or ferric sulfate to facilitate 

leaching and reduce alkalinity. Unless drainage systems are 

maintained, the soil has a seasonal high water table during 

the irrigation season. Dikes need to be maintained to 

provide continuing protection from flooding. 

Furrow, corrugation, and sprinkler irrigation systems are 

suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. If surface irrigation is 

used, the hazard of erosion can be minimized by keeping 

runs short. Sprinkler irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs.

Proper timing of tillage, use of minimum tillage, and return 

of crop residue to the soil help to avoid compaction, help to 

maintain or improve the organic matter content, help to 

maintain tilth, and improve the water infiltration rate. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation and maintaining crop residue on the 

surface reduce water erosion. Using vegetated filter strips at 

the end of rows or using sediment ponds, or both, reduces 

the volume of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and wetness. 

Flooding can be controlled by the use of dikes and channels 

that have outlets to bypass floodwater. Wetness can be 

reduced by installing drain tile around footings. Dustiness 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is 

wetness. Deep drainage helps to overcome this limitation. 

This map unit is in capability subclass Illw, irrigated. 

170-Umapine silt loam, drained, 2 to 5 percent 

slopes. This very deep, artificially drained, salt- and alkaliaffected soil is on flood plains and low terraces. It formed in 

alluvium. The native vegetation is mainly salt- and alkalitolerant grasses, forbs, and shrubs. Elevation is 650 to 900 

feet. The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 130 to 180 days. 

Typically, the surface layer is light brownish gray, very 

strongly alkaline silt loam about 7 inches thick. The 

underlying material to a depth of 60 inches or more is light 

brownish gray and light gray, very strongly alkaline and 

strongly alkaline silt loam. In some areas the surface layer is 

dark gray. 

Included in this unit are areas of Esquatzel, Toppenish, and 

Warden soils. Also included are areas of soils that 
are underlain by a hardpan at a depth of 20 to 40 inches 

and Umapine soils that have not been artificially drained. 

Permeability of this Umapine soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. A seasonal high water table is at a depth of 24 to 48 

inches from November to June. Runoff is very slow, and the 

hazard of water erosion is moderate. This unit is subject to 

rare periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. The main irrigated crops are asparagus, 

corn, hops, peas, and grain. Grasses and legumes are 

grown for hay, pasture, and seed. 

The main limitations for irrigated crops are alkalinity and 

the hazard of water erosion. Reclamation of the soil in this 

unit may require the addition of such amendments as 

gypsum, sulfur, or ferric sulfate to facilitate leaching and 

reduce alkalinity. Unless drainage systems are 

maintainers the soil has a seasonal high water table during 

the irrigation season. Dikes need to be maintained to provide 

protection from flooding. 

Furrow, corrugation, and sprinkler irrigation 

systems are suited to the soil in this unit. The type of 

system used depends on the kind of crop grown. If 

surface irrigation is used, runs should be on the contour 

or across the slope. Sprinkler irrigation permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. 

Cultivation prior to irrigation improves the infiltration rate; 

however, the fine soil particles dislodged during cultivation 

are highly susceptible to erosion. This makes the initial 

period of irrigation extremely critical. The water application 

rate should be reduced accordingly to help control runoff, 

erosion, and the production of sediment. To avoid loss of 

water and leaching of plant nutrients from overirrigation, 

application of irrigation water should also be adjusted to the 

available water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, 

high-residue crops in the rotation and maintaining crop 

residue on the surface reduce water erosion. Growing mint 

in meadows rather than in rows greatly reduces erosion. 

Using vegetated filter strips at the end of rows or using 

sediment ponds, or both, reduces the volume of sediment 

in the tailwater. A plowpan develops in this soil; however, it 

can be broken by chiseling or subsoiling when the soil is 

dry. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and wetness. 

Flooding can be controlled by the use of dikes and channels 

that have outlets to bypass floodwater. Wetness can be 

reduced by installing drain tile around footings. Dustiness can 

be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

The main limitation for septic tank absorption fields is 

wetness. Deep drainage helps to overcome this limitation. 

This map unit is in capability subclass IIIw, irrigated. 

171-Wanser loamy fine sand. This very deep, artificially 

drained, salt- and alkali-affected soil is on terraces in 

basins. It formed in sand. Slope is 0 to 5 percent. The native 

vegetation is mainly salt- and alkali-tolerant grasses and 

forbs. Elevation is 650 to 1,100 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 120 to 135 days. 

Typically, the surface layer is grayish brown, moderately 

alkaline loamy fine sand about 6 inches thick. The upper 

part of the underlying material is dark grayish brown and 

grayish brown, moderately alkaline and strongly alkaline 

loamy fine sand about 51 inches, and the lower part to a 

depth of 60 inches or more is light brownish gray, strongly 

alkaline fine sand. 

Included in this unit are areas of Hezel, Quincy, and 

Esquatzel soils and areas of Wanser soils that have not 

been artificially drained. 

Permeability of this Wanser soil is rapid. Available water 

capacity is moderately high. Effective rooting depth is 60 

inches or more. Runoff is very slow, and the hazard of 

water erosion is slight. The hazard of soil blowing is high. A 

seasonal high water table is at a depth of 42 to 60 inches 

from January to June. The soil is subject to rare periods of 

flooding. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. The main irrigated crops are grain and corn. 

Grasses and legumes are grown for hay, pasture, and seed.

The main limitations for irrigated crops are wetness, low 

available water capacity, and the hazard of soil blowing. 

Deep-rooted crops are suited to areas where the drainage is 

adequate or where a drainage system has been installed 

and is maintained. Reclamation of the soil in this unit may 

require the addition of such amendments as gypsum, 

sulphur, or ferric sulfate to facilitate leaching. Unless 

drainage systems are maintained, the soil has a seasonal 

high water table during the irrigation season. Dikes need to 

be maintained to provide protection for flooding. 

Sprinkler irrigation systems are suited to the soil in this 

unit. Use of these systems permits the even, controlled 

application of irrigation water, reduces runoff, and minimizes 

the risk of water erosion. The type of irrigation system used 

depends on the kind of crop grown. To avoid leaching of 

plant nutrients and loss of water by deep percolation, the 

water application rate should be adjusted to the available 

water capacity, the water intake rate, and the crop needs. 

Frequent, light applications of irrigation water are needed 

because of the rapid permeability of the soil. 
The high hazard of soil blowing makes tillage and 

residue management extremely important. The soil should 

not be left barren while it is subject to erosion in winter and 

spring. Winter cover crops should be planted early and at 

right angles to the prevailing wind. Fall grain, hay, and 

pasture should be seeded late in August or early in 

September to provide sufficient cover in winter. Seedbed 

preparation should be done when irrigation water is available 

to keep the soil surface moist. Sufficient crop residue 

should be left on the surface. Use of straw, manure, or other 

waste material as a mulch reduces soil blowing, helps to 

maintain or improve the organic matter content, and 

conserves moisture. Use of shelterbelts also reduces soil 

blowing. 

This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Flooding can be 

controlled by use of dikes and channels that have outlets 

to bypass floodwater. Because of the high hazard of soil 

blowing, construction sites should be disturbed as little as 

possible. Cutbanks are not stable and are subject to 

caving in. 

The main limitations for septic tank absorption fields are 

wetness and seepage. Wetness increases the possibility of 

the failure of the septic tank absorption fields. If the density 

of housing is moderate to high, community sewage 

systems are needed to prevent contamination of water 

supplies as a result of seepage. 

This map unit is in capability subclass IVw, irrigated. 

172-Warden fine sandy loam, 0 to 2 percent slopes. 

This very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 600 to 1,000 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is brown fine sandy loam about 

5 inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or 

more is light gray and pale brown, stratified silt loam, loam, 

and very fine sandy loam. In some areas the surface layer is 

silt loam, and in some areas the soil is calcareous 

throughout. 

Included in this unit are areas of Shano, Burke, 

Harwood, Wiehl, and Esquatzel soils. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or

more. Runoff is very slow, and the hazard of water erosion 

is slight. The hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are corn, grain, grapes, hops, mint, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of soil 

blowing. Furrow, corrugation, trickle, drip, and 

sprinkler irrigation systems are suited to the soil in this unit. 

The type of irrigation system used depends on the kind of 

crop grown. Use of sprinkler and drip irrigation systems 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. To avoid loss of 

water and leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity, the water intake rate, and the crop 

needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce soil blowing. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation reduces erosion. The soil should be 

protected from erosion by growing a cover crop or by 

maintaining crop residue on the surface in spring or until the 

crops are well established. Crop rows and irrigation furrows 

should be placed at right angles to the prevailing wind where 

feasible to reduce soil blowing. Vegetative barriers and 

windbreaks also reduce soil blowing. Mulching may be 

needed to stabilize small areas where soil blowing begins. A 

plowpan develops in this soil; however, it can be broken by 

chiseling or subsoiling when the soil is dry. Using vegetated 

filter strips at the end of rows or using sediment ponds, or 

both, reduce the volume of sediment in the tailwater. 

This unit is well suited to homesite development. Soil 

blowing can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclass Ile, irrigated. 

173-Warden fine sandy loam, 2 to 5 percent slopes. 

This very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

600 to 1,000 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown fine sandy loam about 

5 inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or more 

is light gray and pale brown, stratified silt loam, loam, and 

very fine sandy loam. In some areas the surface layer is silt 

loam. 

Included in this unit are small areas of Shano, Harwood, 

Burke, Wiehl, Outlook, and Esquatzel soils and Warden soils 

that have slopes of less than 2 percent. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is slow, and the hazard of water erosion is 

slight. The hazard of soil blowing is high. 

The unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 
homesites. The main irrigated crops are corn, grain, 

grapes, hops, mint, peas, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are the 

hazards of soil blowing and water erosion. Furrow, 

corrugation, drip, and sprinkler irrigation systems are suited 

to the soil in this unit. The type of system used depends on 

the kind of crop grown. If furrow and corrugation irrigation 

systems are used, runs should be on the contour or across 

the slope. The risk of water erosion can be minimized by 

keeping runs short. Use of sprinkler and drip irrigation 

systems permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of water erosion. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should be 

adjusted to the available water capacity, the water intake 

rate, and the crop needs. Pipe, ditch lining, or drop 

structures should be installed in irrigation ditches to facilitate 

irrigation and prevent excessive ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce soil blowing. Using a 

cropping system that includes close-growing, highresidue crops in the rotation reduces erosion. The soil 

should be protected from erosion by growing cover crops 

or maintaining crop residue on the surface in spring or until 

the crop is well established. Crop rows and irrigation 

furrows should be established at right angles to the 

prevailing wind where feasible. Vegetative barriers and 

windbreaks reduce soil blowing. Mulching may be 

needed to stabilize small areas where soil blowing begins. 

Growing mint in meadows rather than in rows greatly 

reduces water erosion. A plowpan develops in this soil; 

however, it can be broken by subsoiling. Using vegetated 

filter strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazards of soil blowing and water 

erosion. Because precipitation is not sufficient for annual 

cropping, a cropping system that includes winter wheat 

and summer fallow is most suitable. Erosion can be reduced 

by seeding fall grain early and stubble mulching. 

Stripcropping and seeding at right angles to the prevailing 

wind reduce soil blowing. Drop structures are needed in a 

few places to stabilize the flow of runoff in waterways. 

Waterways may need to be shaped and seeded to perennial 

grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass and needIeandthread. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as railing, chaining, beating, 

plowing, chemical treatment, and prescribed burning. 

Range seeding is a suitable practice if the range 

vegetation is in poor condition. The soil in this unit should 

be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This unit is well suited to homesite development. Soil 

blowing can be a concern during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclasses Ile, irrigated, and 

IVe, nonirrigated. 

174-Warden fine sandy loam, 5 to 8 percent slopes. 

This very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

600 to 1,000 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown fine sandy loam 

about 5 inches thick. The subsoil is pale brown silt loam 

about 14 inches thick. The substratum to a depth of 60 

inches or more is light gray and pale brown, stratified silt 

loam, loam, and very fine sandy loam. In some areas the 

surface layer is silt loam. 

Included in this unit are small areas of Shano soils. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water erosion 

is moderate. The hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are corn, grain, grapes, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazards of soil blowing and water erosion. 

Sprinkler and drip irrigation systems are suited to the soil in 

this unit. The type of system used depends on the kind of 

crop grown. Use of these irrigation systems permits the 

even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce soil blowing. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation reduces erosion. The soil should be 

protected from soil blowing by maintaining crop residue on 

the surface in spring or until the crops 
are well established. Crop rows and irrigation furrows should 

be established at right angles to the prevailing wind where 

feasible. Vegetative barriers and windbreaks also reduce 

soil blowing. Mulching may be needed to stabilize small 

areas where soil blowing begins. A plowpan develops in this 

soil; however, it can be broken by chiseling or subsoiling 

when soil is dry. 

The potential native vegetation is mainly bluebunch 

wheatgrass and needleandthread. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as railing, chaining, beating, plowing, chemical treatment, 

and prescribed burning. Range seeding is a suitable 

practice if the range vegetation is in poor condition. The 

soil in this unit should be seeded in the fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is well suited to homesite development. Soil 

blowing is a concern during construction on large building 

sites; therefore, these sites should be disturbed as little as 

possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclasses Ille, irrigated, and 

IVe, nonirrigated. 

175-Warden fine sandy loam, 8 to 15 percent 

slopes. This very deep, well drained soil is on terraces. It 

formed in lacustrine sediment and has a mantle of loess. 

The native vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 600 to 1,000 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is brown fine sandy loam about 

5 inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or 

more is light gray and pale brown, stratified silt loam, loam, 

and very fine sandy loam. In some areas the surface layer is 

silt loam. 

Included in this unit are small areas of Shano soils, soils 

that have a salt- and alkali-affected surface layer, and 

Warden soils that have slopes of less than 8 percent. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is rapid, and the hazard of water erosion is 

high. The hazard of soil blowing is high. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, 

grapes, and tree fruit. Grasses and legumes are grown 

for pasture, hay, and seed. A cover crop is grown in 

orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazards of soil blowing and water erosion. A 

rotation of grain followed by alfalfa and grass commonly is 

used. Sprinkler and drip irrigation systems are suited to the 

soil in this unit. Use of these systems permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce the risk of soil blowing. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces erosion. The soil should 

be protected from soil blowing by maintaining crop residue 

on the surface in spring or until the crops are well 

established. Crop rows and irrigation furrows should be 

established at right angles to the prevailing wind where 

feasible. Vegetative barriers and windbreaks also reduce soil 

blowing. Mulching may be needed to stabilize small areas 

where soil blowing begins. Cover crops reduce erosion in 

orchards and vineyards. A plowpan develops in this soil; 

however, it can be broken by chiseling or subsoiling when 

the soil is dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazards of soil blowing and water 

erosion. Because precipitation is not sufficient for annual 

cropping, a cropping system that includes winter wheat and 

summer fallow is most suitable. Erosion can be reduced by 

seeding fall grain early, stubble mulching, stripcropping, and 

seeding at right angles to the prevailing wind. Drop 

structures are needed in a few areas to stabilize the flow of 

runoff in waterways. Waterways may need to be shaped 

and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass and needleandthread. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as railing, chaining, beating, plowing, chemical treatment, 

and prescribed burning. Range seeding is a suitable 

practice if the range vegetation is in poor condition. The 

soil in this unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is suited to homesite development. The main 

limitation for use as homesites and septic tank absorption 

fields is steepness of slope. Slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

Lateral seepage can be avoided by installing absorption lines 

on the contour. Soil blowing may be a 
problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

This map unit is in capability subclass IVe, irrigated and 

nonirrigated. 

176-Warden silt loam, 0 to 2 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

600 to 1,000 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or 

more is light gray and pale brown, stratified silt loam, loam, 

and very fine sandy loam. In some areas the surface layer is 

fine sandy loam. 

Included in this unit are small areas of Shano, Harwood, 

Wiehl, Burke, and Esquatzel soils and areas of salt- and 

alkali-affected soils. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is slow, and the water erosion hazard is 

slight. 

This unit is used for irrigated field and orchard crops, for 

wildlife habitat, and as homesites. The main irrigated crops 

are corn, grain, grapes, hops, mint, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and seed. 

This unit has few limitations for crops. Furrow, 

corrugation, drip, and sprinkler irrigation systems are suited 

to the soil in this unit. The type of system used depends on 

the kind of crop grown. If surface irrigation systems are 

used, the risk of erosion can be minimized by keeping runs 

short. Use of sprinkler or drip irrigation permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications 

of irrigation water should also be adjusted to the available 

water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue 

on the surface reduce water erosion. Cover crops reduce 

erosion in orchards and vineyards. A plowpan develops in 

this soil; however, it can be broken by chiseling or 

subsoiling when the soil is dry. Using vegetated filter strips 

at the end of rows or 

using sediment ponds, or both, reduces the volume of 

sediment in the tailwater. 

This unit is well suited to homesite development. 

Dustiness is a concern during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability class I, irrigated. 

177-Warden silt loam, 2 to 5 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

600 to 1,000 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or 

more is light gray and pale brown, stratified silt loam, loam, 

and very fine sandy loam. In some areas the surface layer 

is fine sandy loam. 

Included in this unit are small areas of Shano, Harwood, 

Burke, Wiehl, and Esquatzel soils. Also included are areas 

of salt- and alkali- affected soils and areas of Warden soils 

that have slopes of less than 2 percent or more than 5 

percent. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches 

or more. Runoff is medium, and the hazard of water erosion 

is moderate. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are corn, grain, grapes 

(fig. 7), hops, mint, peas, and tree fruit. Grasses and 

legumes are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of 

water erosion. Furrow, corrugation, drip, and sprinkler 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. If furrow 

or corrugation systems are used, runs should be on the 

contour or across the slope. The risk of erosion can be 

minimized by keeping runs short. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to help 

control runoff, erosion, and the production of sediment. To 

avoid loss of water and 
Figure 7-Vineyard under drip irrigation on Warden silt loam, 2 to 5 percent slopes. 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should also be adjusted to the available 

water capacity and the crop needs. Pipe, ditch lining, or drop 

structures should be installed in irrigation ditches to facilitate 

irrigation and reduce ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration 

rate. Using a cropping system that includes close-growing, 

high-residue crops in the rotation and maintaining crop 

residue on the surface reduce water erosion. Growing mint 

in meadows rather than in rows greatly reduces erosion. 

Growing cover crops reduces erosion in orchards and 

vineyards. A plowpan develops in this soil; however, it can 

be broken by chiseling or subsoiling when the soil is dry. 

Using vegetated filter 

strips at the end of rows or using sediment ponds, or 

both, reduces the volume of sediment in the tailwater. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 

Because precipitation is not sufficient for annual cropping, 

a cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by 

seeding fall grain early, stubble mulching, and shaping 

waterways and seeding them to perennial grass. Drop 

structures are needed in a few areas to stabilize the flow 

of runoff in waterways. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants 

such as bluebunch wheatgrass decreases and the 

proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. Areas that are 
heavily infested with undesirable vegetation can be 

improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition. The soil in this unit should 

be seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This unit is well suited to homesite development. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit is in capability subclass lIe, irrigated and 

IVe, nonirrigated. 

178-Warden silt loam, 5 to 8 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. 

Elevation is 600 to 1,000 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 180 days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or 

more is light gray and pale brown, stratified silt loam, loam, 

and very fine sandy loam. In some areas the surface layer 

is fine sandy loam. 

Included in this unit are small areas of Shano soils and 

areas of Warden soils that have slopes of less than 5 

percent or more than 8 percent. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for irrigated field and orchard crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are corn, grain, grapes, peas, and tree fruit. 

Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. The type 

of system used depends on the kind of crop grown. Use of 

these irrigation systems permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. Cultivation prior to irrigation improves the water 

infiltration rate; however, the fine soil particles dislodged 

during cultivation are highly susceptible to water erosion. 

This makes the initial period of irrigation extremely critical. 

The water application rate should be reduced accordingly to 

help control runoff, erosion, and the production of sediment. 

To avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should 

also be adjusted to the available water capacity and the 

crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and improve the water infiltration rate. 

Using a cropping system that includes close-growing, highresidue crops in the rotation and maintaining crop residue 

on the surface reduce water erosion. Cover crops reduce 

erosion in orchards and vineyards. A plowpan develops in 

this soil; however, it can be broken by chiseling or subsoiling 

when the soil is dry. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as railing, chaining, beating, plowing, chemical treatment, 

and prescribed burning. Range seeding is a suitable 

practice if the range vegetation is in poor condition. The 

soil in this unit should be seeded in fall using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is well suited to homesite development. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This unit has few limitations for septic tank absorption 

fields. 

This map unit in is capability subclass Ille, irrigated. 

179-Warden silt loam, 8 to 15 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

600 to 1,000 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or 

more is light gray and pale brown, stratified silt loam, loam, 

and very fine sandy loam. In some areas the surface layer is 

fine sandy loam. 

Included in this unit are small areas of Harwood, Burke, 

Wiehl, Esquatzel, and Shano soils. Also included are 

areas of soils that have a salt- and alkali-affected surface 

layer and soils that have slopes of less than 8 percent or 

more than 15 percent. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is rapid, and the hazard of water erosion is 

high. 
This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grapes and tree fruit. 

Grass and legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are the steepness 

of slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the infiltration rate; 

however, the fine soil particles dislodged during cultivation are 

highly susceptible to water erosion. This makes the initial 

period of irrigation extremely critical. The water application 

rate should be reduced accordingly to help control runoff, 

erosion, and the production of sediment. To avoid loss of 

water and leaching of plant nutrients from overirrigation, 

applications of irrigation water should also be adjusted to the 

available water capacity and the crop needs. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. Cover 

crops reduce erosion in orchards and vineyards. A plowpan 

develops in this soil; however, it can be broken by chiseling 

or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, using terraces and diversions, 

and stripcropping. Seeding on the contour or across the 

slope slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial grass.

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as railing, chaining, beating, plowing, 

chemical treatment, and prescribed burning. Range 

seeding is a suitable practice if the range vegetation is in 

poor condition. The soil in this unit should be seeded in fall 

using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is suited to homesite development. The main 

limitation for use as homesites and septic tank absorption 

fields is steepness of slope. Slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

Lateral seepage can be reduced by installing absorption 

lines on the contour. Dustiness can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

This map unit is in capability subclass IVe, irrigated 

and nonirrigated. 

180-Warden silt loam, 15 to 30 percent slopes. This 

very deep, well drained soil is on terraces. It formed in 

lacustrine sediment and has a mantle of loess. The native 

vegetation is mainly grasses, forbs, and shrubs. Elevation is 

600 to 1,000 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typically, the surface layer is brown silt loam about 5 

inches thick. The subsoil is pale brown silt loam about 14 

inches thick. The substratum to a depth of 60 inches or more 

is light gray and pale brown, stratified silt loam, loam, and 

very fine sandy loam. In some areas the surface layer is fine 

sandy loam. 

Included in this unit are small areas of Shano, Scooteney, 

and Burke soils. Also included are areas of soils that have a 

salt- and alkali-affected surface layer and areas of Warden 

soils that have slopes of less than 15 percent or more than 

30 percent. 

Permeability of this Warden soil is moderate. Available 

water capacity is high. Effective rooting depth is 60 inches or 

more. Runoff is rapid, and the hazard of water erosion is 

high. 

This unit is used for irrigated field and orchard crops, 

nonirrigated crops, rangeland, wildlife habitat, and 

homesites. The main irrigated crops are grain, grapes, and 

tree fruit. Grass and legumes are grown for hay, pasture, 

and seed. A cover crop is grown in orchards. 

The main limitations for irrigated crops are steepness of 

slope and the hazard of water erosion. Sprinkler and drip 

irrigation systems are suited to the soil in this unit. Use of 

these systems permits the even, controlled application of 

water, reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation increases the water infiltration 

rate; however, the fine soil particles dislodged during 

cultivation are highly susceptible to water erosion. This 

makes the initial period of irrigation extremely critical. The 

water application rate should be reduced accordingly to 

reduce runoff, erosion, and the production of sediment. To 

avoid loss of water and leaching of plant nutrients from 

overirrigation, applications of irrigation water should also be 

adjusted to the available water capacity and the crop needs. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces water erosion. Cover 

crops reduce erosion in orchards and vineyards. A plowpan 

develops in this soil from excessive tillage; however, it can 

be broken by chiseling or subsoiling when the soil is dry. 

The main limitations for nonirrigated crops are low 

annual precipitation and the hazard of water erosion. 
Because precipitation is not sufficient for annual cropping, a 

cropping system that includes winter wheat and summer 

fallow is most suitable. Erosion can be reduced by seeding 

fall grain early, stubble mulching, divided-slope farming, 

and stripcropping. Seeding on the contour or across the 

slope slows runoff and reduces erosion when the snow 

melts rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass and Sandberg bluegrass. If the range is 

overgrazed, the proportion of preferred forage plants such 

as bluebunch wheatgrass decreases and the proportion of 

less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested 

with undesirable vegetation can be improved by such 

methods as railing, chaining, beating, plowing, 

chemical treatment, and prescribed burning. Range 

seeding is a suitable practice if the range vegetation is in 

poor condition. The soil in this unit should be seeded in fall 

using a drill. Adapted grasses and legumes should be 

seeded. 

This unit is poorly suited to homesite development. The 

main limitation for homesites and septic tank absorption 

fields is steepness of slope. Slope can cause lateral 

seepage and surfacing of effluent in downslope areas. 

Dustiness can be a problem during construction on large 

building sites; therefore, these sites should be disturbed as 

little as possible. 

This map unit is in capability subclass IVe, 

irrigated and nonirrigated. 

181-Weirman sandy loam, channeled. This very deep, 

somewhat excessively drained soil is on low terraces and 

flood plains (fig. 8). The soil is dissected by intermittent and 

perennial streams. It formed in mixed alluvium. Slope is 0 to 

5 percent. The native vegetation is mainly grasses, forbs, 

and shrubs. Elevation is 700 to 1,700 feet. The average 

annual precipitation is 7 to 14 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is grayish brown sandy loam 

about 8 inches thick. The upper part of the underlying 

material is grayish brown and light brownish gray 

loamy fine sand about 13 inches thick, and the lower part to 

a depth of 60 inches or more is grayish brown extremely 

gravelly sand. In some areas the surface layer is fine sandy 

loam or is gravelly, cobbly, or stony sandy loam. 

Included in this unit are areas of Zillah, Logy, and 

Yakima soils. 

Permeability of this Weirman soil is rapid. Available water 

capacity is low. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 36 to 60 

inches from April to November. Runoff is slow, and the 

hazard of water erosion is slight. The hazard of soil 

blowing is high. This unit is subject to frequent periods of 

flooding in spring. 

This unit is used as rangeland and for wildlife habitat. 

The potential native vegetation is mainly basin wildrye, 

bluebunch wheatgrass, big bluegrass, and willows. The main 

limitation for the production of forage is low available water 

capacity. If the range is overgrazed, the proportion of 

preferred forage plants such as basin wildrye and bluebunch 

wheatgrass decreases and the proportion of less preferred 

plants increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods as 

railing, chaining, beating, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition, but seeding is difficult 

because of the areas that have cobbly or stony surface 

layer. The soil in this unit should be seeded in fall using a 

drill. Adapted grasses and legumes should be seeded. 

This unit is limited for livestock watering ponds and other 

water impoundments because of seepage potential. Water 

tanks, springs, and pipeline systems are more effective and 

reliable means of providing water for livestock. 

This map unit is in capability subclass Vlw, 

nonirrigated. 

182-Weirman fine sandy loam. This very deep, 

somewhat excessively drained soil is on low terraces and 

flood plains. It formed in mixed alluvium. Slope is 0 to 2 

percent. The native vegetation is mainly grasses, forbs, and 

shrubs. Elevation is 700 to 1,700 feet. The average annual 

precipitation is 7 to 14 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typically, the surface layer is grayish brown fine sandy 

loam about 8 inches thick. The upper part of the underlying 

material is stratified, grayish brown and light brownish gray 

loamy fine sand about 13 inches thick, and the lower part to 

a depth of 60 inches or more is grayish brown extremely 

gravelly sand. 

Included in this unit are areas of Ashue, Zillah, Logy, 

and Yakima soils. 

Permeability of this Weirman soil is rapid. Available water 

capacity is low. Effective rooting depth is 60 inches or 

more. Runoff is slow, and the hazard of water erosion is 

slight. The hazard of soil blowing is high. The soil is subject 

to rare periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. The main irrigated crops are corn, grain, 

grapes, and peas. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitations for irrigated crops are the hazard of 

soil blowing and low available water capacity. Furrow, 

corrugation, and sprinkler irrigation systems are suited to the 

soil in this unit. The type of system used depends on the 

kind of crop grown. If surface irrigation systems are used, 

the risk of erosion can be minimized by keeping 
Figure 8.-Weirman sandy loam, channeled, with riparian vegetation. 

runs short. Use of sprinkler irrigation permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications 

of irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce the risk of soil blowing. 

Using a cropping system that includes close-growing, highresidue crops in the rotation reduces erosion. The soil 

should be protected from erosion by maintaining crop 

residue on the surface until crops are well established in 

spring. Crop rows and irrigation 

furrows should be established at right angles to the 

prevailing wind where feasible. Vegetative barriers 

and windbreaks also reduce soil blowing. Mulching helps to 

stabilize small areas where soil blowing begins. Using 

vegetated filter strips at the end of rows reduces the 

volume of sediment in the tailwater. Exposing the 

extremely gravelly underlying material should be 

avoided when leveling fields. Shallow cuts are feasible in 

selected areas. 

This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Flooding can be 

controlled by use of dikes and channels that have outlets to 

bypass floodwater. Soil blowing can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as 
possible. Cutbanks are not stable and are subject to caving 

in. 

The main limitation for septic tank absorption fields is seepage. 

If the density of housing is moderate to high, community sewage 

systems are needed to prevent contamination of water supplies 

as a result of seepage from onsite sewage disposal systems. 

This map unit is in capability subclass IVe, irrigated. 

183-Weirman gravelly fine sandy loam. This very deep, 

somewhat excessively drained soil is on low terraces and flood 

plains. It formed in mixed alluvium. Slope is 0 to 5 percent. The 

native vegetation is mainly grasses, forbs, and shrubs. Elevation 

is 700 to 1,700 feet. The average annual precipitation is 7 to 14 

inches, the average annual air temperature is about 51 degrees 

F, and the average frost-free season is 130 to 180 days. 

Typically, the surface layer is grayish brown gravelly fine 

sandy loam about 8 inches thick. The upper part of the underlying 

material is stratified, grayish brown and light brownish gray 

loamy fine sand about 13 inches thick, and the lower part to a 

depth of 60 inches or more is grayish brown extremely gravelly 

sand. In some areas the surface layer is sandy loam or fine 

sandy loam, or it is gravelly, cobbly, or stony. 

Included in this unit are areas of Zillah, Logy, and Yakima 

soils. 

Permeability of this Weirman soil is rapid. Available water 

capacity is low. Effective rooting depth is 60 inches or more. 

Runoff is slow, and the hazard of water erosion is slight. The 

hazard of soil blowing is moderate. The soil is subject to rare 

periods of flooding. 

The unit is used for irrigated crops, for wildlife habitat, and as 

homesites. The main irrigated crops are corn, grain, and 

grapes. Grasses and legumes are grown for hay, pasture, and 

seed. 

The main limitations for irrigated crops are low available water 

capacity and the hazard of soil blowing. Furrow, corrugation, and 

sprinkler irrigation systems are suited to the soil in this unit. 

The type of system used depends on the kind of crop grown. If 

surface irrigation systems are used, the risk of erosion can be 

minimized by keeping runs short and establishing them on the 

contour or across the slope. Use of sprinkler irrigation permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications of 

irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the soil 

help to maintain or improve the organic matter content, help to 

maintain tilth, and reduce soil blowing. Using a cropping system 

that includes close-growing, high-residue crops in the rotation 

and using vegetative barriers and windbreaks also reduce soil 

blowing. The soil should be protected from soil blowing by 

maintaining 

crop residue on the surface until the crops are well established 

in spring. Crop rows and irrigation furrows should be 

established at right angles to the prevailing wind where 

feasible. Mulch can be used to stabilize small areas where 

soil blowing begins. Using vegetated filter strips at the end 

of rows reduces the volume of sediment in the tailwater. 

Exposing the extremely gravelly underlying material should 

be avoided when leveling fields. Shallow cuts are feasible in 

some areas. 

This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Flooding can be 

controlled by the use of dikes and channels that have outlets 

to bypass floodwater. Soil blowing can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

The main limitation for septic tank absorption fields is 

seepage. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage. 

This map unit is in capability subclass IVe, irrigated. 

184-Weirman fine sandy loam, wet. This very deep soil is on 

flood plains. It formed in mixed alluvium. Slope is 0 to 2 percent. 

The native vegetation is mainly water-tolerant sedges and 

rushes. Elevation is 700 to 1,700 feet. The average annual 

precipitation is 7 to 14 inches, the average annual air 

temperature is about 51 degrees F, and the average frost-free 

season is 130 to 180 days. 

Typically, the surface layer is grayish brown fine sandy loam 

about 8 inches thick. The upper part of the underlying material is 

stratified, grayish brown and light brownish gray loamy fine 

sand about 13 inches thick, and the lower part to a depth of 60 

inches or more is grayish brown gravelly sand. In some areas the 

surface layer is silt loam or is gravelly or cobbly. 

Included in this unit are areas of Zillah, Logy, and Yakima 

soils. 

Permeability of this Weirman soil is rapid. Available water 

capacity is low. Effective rooting depth is limited by a seasonal 

high water table that is at a depth of 12 to 24 inches from April 

to November. Runoff is very slow, and the hazard of water 

erosion is slight. The hazard of soil blowing is high. The soil is 

subject to occasional periods of flooding in spring. 

This unit is used for irrigated crops and as homesites. Where 

the soil in the unit is drained and protected from flooding, the 

main irrigated crops are corn, grain, and peas. Grasses and 

legumes are grown for hay and pasture. 

The main limitations for irrigated crops are wetness, the 

hazard of soil blowing, and low available water capacity. Deeprooted crops are suited to areas where the natural drainage 

is adequate or where a drainage system has been installed. 

Dikes can be used to divert floodwater. 
Furrow, corrugation, drip, and sprinkler irrigation systems 

are suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. If surface irrigation 

systems are used, the risk of erosion can be minimized by 

keeping runs short. Sprinkler irrigation permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, applications 

of irrigation water should be adjusted to the available water 

capacity, the water intake rate, and the crop needs. 

Proper timing of minimum tillage reduces compaction. 

Return of crop residue to the soil helps to maintain or 

improve the organic matter content, helps to maintain tilth, 

and reduces soil blowing. Using a cropping system that 

includes close-growing, high-residue crops in the rotation 

and using vegetative barriers and windbreaks also reduce 

soil blowing. The soil should be protected from soil 

blowing by maintaining crop residue on the surface until the 

crops are well established in spring. Crop rows and 

irrigation furrows should be established at right angles to 

the prevailing wind where feasible. Mulch can be used to 

stabilize small areas where soil blowing begins. 

Using vegetated filter strips at the end of rows or using 

sediment ponds, or both, reduces the volume of sediment 

in the tailwater. A plowpan develops in this soil; however, it 

can be broken by chiseling or subsoiling when the soil is 

dry. Exposing the extremely gravelly substratum should be 

avoided when leveling fields. Shallow cuts are feasible in 

some areas. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and wetness. 

Flooding can be controlled by use of dikes and channels 

to bypass floodwater. Deep drainage reduces the 

problem of wetness. Soil blowing can be a problem 

during construction on large building sites; therefore, these 

sites should be disturbed as little as possible. Cutbanks 

are not stable and are subject to caving in. 

The main limitations for septic tank absorption fields are 

the hazard of flooding, wetness, and seepage. Wetness 

increases the possibility of failure of septic tank absorption 

fields. If the density of housing is moderate to high, 

community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage. 

This map unit is in capability subclass IVw, irrigated. 

185-Wenas silt loam. This very deep, artificially 

drained soil is on flood plains. It formed in alluvium. Slope 

is 0 to 2 percent. The native vegetation is mainly watertolerant grasses and forbs. Elevation is 1,100 to 1,800 

feet. The average annual precipitation is 8 to 12 inches, 

the average annual air temperature is about 50 degrees 

F, and the average frost-free season is 130 to 180 

days. 

Typically, the surface layer is dark gray silt loam about 8 

inches thick. The upper part of the subsoil is dark 

grayish brown silt loam about 20 inches thick, and the 

lower part is gleyed, gray silty clay loam about 9 inches 

thick. The upper part of the substratum is gleyed, grayish 

brown loam about 10 inches thick, and the lower part to a 

depth of 60 inches or more is gleyed, light brownish gray 

loamy sand and gravelly loamy sand. In some areas the soil 

is calcareous throughout the profile. 

Included in this unit are about 5 percent Esquatzel soils, 

5 percent Kittitas soils, and 5 percent Toppenish soils. 

Also included are areas of soils that are underlain by a 

hardpan at a depth of 20 to 40 inches and areas of 

Wenas soils that are not artificially drained. 

Permeability of this Wenas soil is moderately slow. 

Available water capacity is high. Effective rooting depth is 

limited by a seasonal high water table that is at a depth of 

24 to 42 inches from June to November. Runoff is very 

slow, and the hazard of water erosion is slight. The soil is 

subject to rare periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. Where the soil in this unit is drained, the 

main irrigated crops are grain, hops, and peas. Grasses 

and legumes are grown for hay, pasture, and seed. 

The main limitation for irrigated crops is wetness. Deeprooted crops are suited to areas where a drainage system 

has been installed and is maintained. Dikes can be used 

to divert floodwater. Unless a drainage system is 

maintained, the soil in this unit has a seasonal high water 

table during the irrigation season. 

Furrow, corrugation, drip, and sprinkler irrigation systems 

are suited to the soil in this unit. If surface irrigation 

systems are used, the risk of erosion can be minimized by 

keeping runs short. Use of sprinkler or drip irrigation 

permits the even, controlled application of water, reduces 

runoff, and minimizes the risk of erosion. To avoid loss of 

water and leaching of plant nutrients from overirrigation, 

applications of irrigation water should also be adjusted to 

the available water capacity and the crop needs. 

Proper timing of minimum tillage and return of crop 

residue to the soil reduce compaction, help to maintain or 

improve the organic matter content, help to maintain tilth, 

and improve the water infiltration rate. Using a cropping 

system that includes close-growing, high-residue crops in 

the rotation and maintaining crop residue on the surface 

reduce water erosion. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. A plowpan develops in 

this soil; however, it can be broken by chiseling or 

subsoiling when the soil is dry. 

This unit is poorly suited to homesite development. The 

main limitations are the hazard of flooding and wetness. 

Flooding can be controlled by use of dikes and channels 

that have outlets to bypass floodwater. Deep drainage 

reduces the problem of wetness. Dustiness can be a 

problem during construction on large building sites; 
therefore, these sites should be disturbed as little as 

possible. 

The main limitations for septic tank absorption fields are 

wetness and moderately slow permeability, which increase 

the possibility of failure of the absorption fields. Use of long 

absorption lines and sandy backfill for the trench helps to 

compensate for the moderately slow permeability. 

This map unit is in capability subclass Ilw, irrigated. 

186-Willis fine sandy loam, 2 to 5 percent slopes. 

This well drained soil is on uplands. It is moderately deep 

over a hardpan. It formed in loess. The native vegetation is 

mainly grasses and shrubs. Elevation is 1,200 to 2,500 feet. 

The average annual precipitation is 9 to 12 inches, the 

average annual air temperature is about 49 degrees F, and 

the average frost-free season is 125 to 160 days. 

Typically, the surface layer is grayish brown and brown 

fine sandy loam about 6 inches thick. The subsoil is brown 

silt loam about 16 inches thick. The substratum is brown and 

pale brown silt loam about 12 inches thick. A lime- and silicacemented hardpan is at a depth of about 34 inches. Depth to 

the hardpan ranges from 20 to 40 inches. The hardpan 

generally is underlain by basalt, but in some areas it is 

underlain by gravel and sand or alternate layers of loess and 

hardpan. In some areas the surface layer is silt loam, and in 

some areas hardpan fragments are scattered throughout the 

profile and on the surface. 

Included in this unit are areas of Harwood, Burke, 

Wiehl, Ritzville, Mikkalo, and Moxee soils and areas 

of Willis soils that have slopes of less than 2 percent. 

Permeability of this Willis soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderately high. Effective rooting depth is 20 to 40 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. The hazard of soil blowing is high. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. The main irrigated crops are corn, grain, 

grapes, hops, mint, and peas. Grasses and legumes 

are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are the hazard of 

soil blowing and depth to the hardpan. Furrow, corrugation, 

drip, and sprinkler irrigation systems are suited to the 

soil in this unit. The type of system used depends on the 

kind of crop grown. If furrow or corrugation irrigation 

systems are used, runs should be on the contour or 

across the slope. The risk of erosion can be minimized by 

keeping runs short. Use of sprinkler or drip irrigation permits 

the even, controlled application of water, reduces runoff, and 

minimizes the risk of erosion. To avoid loss of water and 

leaching of plant nutrients from overirrigation, 

applications of irrigation water should be adjusted to the 

available water capacity. Pipe, ditch lining, or drop structures 

should be installed 

in irrigation ditches to facilitate irrigation and prevent 

excessive ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce soil blowing. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation and using vegetative barriers and 

windbreaks also reduce soil blowing. The soil should be 

protected from soil blowing by maintaining crop residue on 

the surface until the crops are well established in spring. 

Crop rows and irrigation furrows should be established at 

right angles to the prevailing wind where feasible. Mulching 

helps to stabilize small areas where soil blowing begins. 

Growing mint in meadows rather than in rows greatly 

reduces erosion. A plowpan develops in this soil; however, it 

can be broken by chiseling or subsoiling when the soil is dry. 

Using vegetated filter strips at the end of rows or using 

sediment ponds, or both, reduces the volume of sediment in 

the tailwater. 

This unit is poorly suited to homesite development. The 

main limitation for use as homesites is the moderate depth 

to the hardpan. The pan hinders excavation. Soil blowing 

can be a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, the 

moderate depth to the hardpan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclass Ile, irrigated. 

187-Willis silt loam, 2 to 5 percent slopes. This well 

drained soil is on uplands. It is moderately deep over a 

hardpan. It formed in loess. The native vegetation is mainly 

grasses and shrubs. Elevation is 1,200 to 2,500 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 125 to 160 days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 6 inches thick. The subsoil is brown silt loam 

about 16 inches thick. The substratum is brown and pale 

brown silt loam about 12 inches thick. A lime- and silicacemented hardpan is at a depth of about 34 inches. Depth 

to the hardpan ranges from 20 to 40 inches. The hardpan 

generally is underlain by basalt, but in some areas it is 

underlain by sand and gravel or alternate layers of loess and 

hardpan. In some areas the surface layer is fine sandy loam, 

and in some areas hardpan fragments are throughout the 

profile and on the surface. 

Included in this unit are small areas of Harwood, 

Burke, Wiehl, Ritzville, Mikkalo, and Moxee soils and 

areas of Willis soils that have slopes of less than 2 

percent. 

Permeability of this Willis soil is moderate above the 

hardpan and very slow through it. Available water 
capacity is moderately high. Effective rooting depth is 20 to 

40 inches. Runoff is medium, and the hazard of water 

erosion is moderate. 

This unit is used for irrigated and nonirrigated crops, as 

rangeland, for wildlife habitat, and as homesites. The main 

irrigated crops are corn, grain, grapes, hops, mint, and 

peas. Grasses and legumes are grown for hay, pasture, 

and seed. 

The main limitations for irrigated crops are the depth to the 

hardpan and the hazard of water erosion. Furrow, 

corrugation, drip, and sprinkler irrigation systems are 

suited to the soil in this unit. The type of system used 

generally depends on the kind of crop grown. If furrow or 

corrugation irrigation systems are used, runs should be 

on the contour or across the slope. The risk of erosion can 

be minimized by keeping runs short. Use of sprinkler or drip 

irrigation permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. 

Cultivation prior to irrigation improves the water 

infiltration rate; however, the fine soil particles dislodged 

during cultivation are highly susceptible to water erosion. 

This makes the initial period of irrigation extremely 

critical. The water application rate should be reduced 

accordingly to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from overirrigation, applications of irrigation 

water should also be adjusted to the available water capacity 

and the crop needs. Pipe, ditch lining, or drop structures 

should be installed in irrigation ditches to facilitate irrigation 

and prevent excessive ditch erosion. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter 

content, help to maintain tilth, and improve the water 

infiltration rate. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Growing mint in meadows rather than in rows 

greatly reduces erosion. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces 

the volume of sediment in the tailwater. Deep cuts should 

be avoided when leveling fields. Shallow cuts are feasible 

in some areas. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, using terraces and diversions, 

and stripcropping. Seeding on the contour or across the 

slope slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grasses. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, and big sagebrush. If the 

range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass decreases and the 

proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. Areas that are heavily 

infested with undesirable vegetation can be improved by 

such methods as chaining, railing, beating, plowing, chemical 

treatment, and prescribed burning. Range seeding is a 

suitable practice if the range vegetation is in poor condition. 

The soil in this unit should be seeded in fail using a drill. 

Adapted grasses and legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation for use as homesites is the moderate depth 

to the hardpan, which hinders excavation. Dustiness can be 

a problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. 

If this unit is used for septic tank absorption fields, 

moderate depth to the hardpan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. 

This map unit is in capability subclasses Ile, irrigated, and 

Ille, nonirrigated. 

188-Willis silt loam, 5 to 8 percent slopes. This well 

drained soil is on uplands. It is moderately deep over a 

hardpan. It formed in loess. The native vegetation is mainly 

grasses and shrubs. Elevation is 1,200 to 2,500 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 125 to 160 days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 6 inches thick. The subsoil is brown silt loam 

about 16 inches thick. The substratum is brown and pale 

brown silt loam about 12 inches thick. A lime- and silicacemented hardpan is at a depth of about 34 inches. Depth to 

the hardpan ranges from 20 to 40 inches. The hardpan 

generally is underlain by basalt, but in some areas it is 

underlain by sand and gravel or alternate layers of loess and 

hardpan. In some areas the surface layer is fine sandy loam, 

and in some areas hardpan fragments are throughout the 

profile and on the surface. 

Included in this unit are small areas of Harwood, 

Burke, Wiehl, Ritzville, Mikkalo, and Moxee soils. 

Permeability of this Willis soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderately high. Effective rooting depth is 20 to 40 inches. 

Runoff is rapid, and the hazard of water erosion is high. 

This unit is used for irrigated and nonirrigated crops, 

rangeland, wildlife habitat, and homesites. The main 

irrigated crops are corn, grain, grapes, and peas. Grasses 

and legumes are grown for hay, pasture, and seed. 
The main limitations for irrigated crops are the depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are 

suited to the soil in this unit. The type of system used 

depends on the kind of crop grown. Use of these irrigation 

systems permits the even, controlled application of water, 

reduces runoff, and minimizes the risk of erosion. Cultivation 

prior to irrigation improves the water infiltration rate; however, 

the fine soil particles dislodged during cultivation are 

highly susceptible to water erosion. This makes the initial 

period of irrigation extremely critical. The water application 

rate should be reduced accordingly to help control runoff, 

erosion, and the production of sediment. To avoid loss of 

water and leaching of plant nutrients from overirrigation, 

applications of irrigation water should also be adjusted to the 

available water capacity and the crop needs. 

Use of minimum tillage andl return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, improve the water infiltration rate, and 

reduce erosion. Using a cropping system that includes 

close-growing, high-residue crops in the rotation and 

maintaining crop residue on the surface reduce water 

erosion. Cover crops reduce erosion in orchards and 

vineyards. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain 

early, stubble mulching, using terraces and diversions, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial 

grasses. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, and big sagebrush. If the 

range is overgrazed, the proportion of preferred forage 

plants such as bluebunch wheatgrass decreases and 

the proportion of less preferred forage plants such as big 

sagebrush and rabbitbrush increases. Areas that are 

heavily infested with undesirable vegetation can be 

improved by such methods as chaining, railing, 

beating, plowing, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition. The soil in this unit should 

be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This unit is poorly suited to homesite development. The 

main limitation for use as homesites is the moderate depth 

to the hardpan, which hinders excavation. Dustiness can be 

a problem during construction on large sites; therefore, these 

sites should be disturbed as little as possible. 

If this unit is used for septic tank absorption fields, the 

hardpan limits the capacity of the absorption fields. Use of 

long absorption lines helps to compensate for this limitation.

This map unit is in capability subclass Ille, irrigated. 

189-Willis silt loam, 8 to 15 percent slopes. This well 

drained soil is on uplands. It is moderately deep over a 

hardpan. It formed in loess. The native vegetation is mainly 

grasses and shrubs. Elevation is 1,200 to 2,500 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 125 to 160 days. 

Typically, the surface layer is grayish brown and brown silt 

loam about 6 inches thick. The subsoil is brown silt loam 

about 16 inches thick. The substratum is brown and pale 

brown silt loam about 12 inches thick. A lime- and silicacemented hardpan is at a depth of about 34 inches. Depth 

to the hardpan ranges from 20 to 40 inches. The hardpan 

commonly is underlain by basalt, but in some areas it is 

underlain by sand and gravel or alternate layers of loess and 

hardpan. In some areas hardpan fragments are throughout 

the profile and on the surface. 

Included in this unit are areas of Harwood, Burke, 

Wiehl, Ritzville, Mikkalo, and Moxee soils. 

Permeability of this Willis soil is moderate above the 

hardpan and very slow through it. Available water capacity is 

moderately high. Effective rooting depth is 20 to 40 inches. 

Runoff is medium, and the hazard of water erosion is 

moderate. 

This unit is used for irrigated and nonirrigated crops, as 

rangeland, for wildlife habitat, and as homesites. The main 

irrigated crops are grain, corn, and grapes. Grass and 

legumes are grown for hay, pasture, and seed. 

The main limitations for irrigated crops are depth to the 

hardpan, steepness of slope, and the hazard of water 

erosion. Sprinkler and drip irrigation systems are suited to 

the soil in this unit. Use of these systems permits the even, 

controlled application of water, reduces runoff, and 

minimizes the risk of erosion. Cultivation prior to irrigation 

improves the water infiltration rate; however, the fine soil 

particles dislodged during cultivation are highly susceptible 

to water erosion. This makes the initial period of irrigation 

extremely critical. The water application rate should be 

reduced accordingly to help control runoff, erosion, and the 

production of sediment. To avoid loss of water and leaching 

of plant nutrients from overirrigation, applications of 

irrigation water should also be adjusted to the available 

water capacity and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, improve the water infiltration rate, and 

reduce erosion. Tillage should be across the slope or on the 

contour. Using a cropping system that includes closegrowing, high-residue crops in 
the rotation and maintaining crop residue on the surface 

reduce water erosion. Annual or perennial cover crops 

reduce erosion in orchards and vineyards. 

The main limitations for nonirrigated crops are low annual 

precipitation and the hazard of water erosion. Because 

precipitation is not sufficient for annual cropping, a cropping 

system that includes winter wheat and summer fallow is most 

suitable. Erosion can be reduced by seeding fall grain early, 

stubble mulching, using terraces and diversions, and 

stripcropping. Seeding on the contour or across the slope 

slows runoff and reduces erosion when the snow melts 

rapidly while the soil is still frozen. Drop structures are 

needed in places to control the flow of runoff in waterways. 

Waterways should be shaped and seeded to perennial grass. 

The potential native vegetation is mainly bluebunch 

wheatgrass, Sandberg bluegrass, and big sagebrush. If the 

range is overgrazed, the proportion of preferred forage plants 

such as bluebunch wheatgrass decreases and the proportion 

of less preferred forage plants such as big sagebrush and 

rabbitbrush increases. Areas that are heavily infested with 

undesirable vegetation can be improved by such methods 

as chaining, railing, beating, plowing, chemical treatment, 

and prescribed burning. Range seeding is a suitable practice 

if the range vegetation is in poor condition. This unit should 

be seeded in fall using a drill. Adapted grasses and legumes 

should be seeded. 

This unit is poorly suited to homesite development. The 

main limitations for use as homesites is the moderate 

depth to the hardpan and steepness of slope. The hardpan 

hinders excavation. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. 

If this unit is used for septic tank absorption fields, the 

moderate depth to the hardpan limits the capacity of the 

absorption fields. Use of long absorption lines helps to 

compensate for this limitation. Slope can cause lateral 

seepage and surfacing of the effluent in downslope areas. 

Absorption lines should be placed on the contour. 

This map unit is in capability subclasses IVe, irrigated and 

Ille, nonirrigated. 

190-Yakima silt loam. This very deep, well drained soil is 

on flood plains. It formed in alluvium. Slope is 0 to 2 percent. 

The native vegetation is mainly grasses and shrubs. 

Elevation is 700 to 1,200 feet. The average annual 

precipitation is 9 to 14 inches, the average annual air 

temperature is about 54 degrees F, and the average frostfree season is 120 to 170 days. 

Typically, the upper part of the surface layer is grayish 

brown silt loam about 13 inches thick. The lower part is dark 

grayish brown sandy loam and brown gravelly very fine 

sandy loam about 14 inches thick. The upper part of the 

underlying material is brown gravelly very fine sandy 

loam about 3 inches thick, and the lower part to a depth 

of 60 inches or more is dark grayish brown extremely gravelly 

coarse sand. In some areas the surface layer is gravelly or 

stony. 

Included in this unit are areas of Logy, Esquatzel, and 

Weirman soils. 

Permeability of this Yakima soil is moderate in the 

surface layer and very rapid in the underlying material. 

Available water capacity is moderately high. Effective rooting 

depth is 60 inches or more. Runoff is very slow, and the 

hazard of water erosion is slight. This unit is subject to 

occasional periods of flooding in spring. 

This unit is used for irrigated crops, for wildlife habitat, and 

as homesites. The main irrigated crops are asparagus, grain, 

grapes, hops, and peas. Grasses and legumes are grown for 

hay, pasture, and seed. 

The main limitation for irrigated crops is the hazard of 

flooding. Dikes are effective in diverting floodwater. Furrow, 

corrugation, and sprinkler irrigation systems are suited 

to the soil in this unit. The type of system used depends on 

the kind of crop grown. If surface irrigation systems are 

used, the risk of erosion can be minimized by keeping runs 

short. Use of sprinkler irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk of 

erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, applications of irrigation water 

should also be adjusted to the available water capacity and 

the crop needs. Pipe, ditch lining, or drop structures should 

be installed in irrigation ditches to facilitate irrigation and 

reduce ditch erosion. 

Proper timing of minimum tillage and return of crop 

residue to the soil reduce compaction, help to maintain or 

improve the organic matter content, help to maintain tilth, and 

improve the water infiltration rate. Using a cropping system 

that includes close-growing, high-residue crops in the rotation 

and maintaining crop residue on the surface reduce water 

erosion. A plowpan develops in this soil; however, it can be 

broken by chiseling or subsoiling when the soil is dry. Using 

vegetated filter strips at the end of rows or using sediment 

ponds, or both, reduces the volume of sediment in the 

tailwater. When leveling fields, care should be taken to avoid 

cutting into the very gravelly part of the substratum. Shallow 

cuts are feasible in some areas. 

This unit is poorly suited to homesite development. The 

main limitation is the hazard of flooding. Flooding can be 

controlled by use of dikes and channels that have outlets 

to bypass floodwater. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Cutbanks are not 

stable and are subject to caving in. 

The main limitations for septic tank absorption fields are 

the hazard of flooding and seepage. If the density of housing 

is moderate to high, community sewage systems are needed 

to prevent contamination of water supplies 
as a result of seepage from onsite sewage disposal 

systems. 

This map unit is in capability subclass Ilw, irrigated. 

191-Zillah sandy loam. This very deep, artificially 

drained soil is on flood plains. It formed in recent alluvium. 

Slope is 0 to 2 percent. The native vegetation is mainly 

water-tolerant trees, sedges, and forbs. Elevation is 600 to 

1,100 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 130 to 180 

days. 

Typically, the surface layer is grayish brown sandy loam 

about 12 inches thick. The upper part of the underlying 

material is gray silt loam about 30 inches thick, and the 

lower part to a depth of 60 inches or more is gray loamy 

sand. In some areas the surface layer is silt loam, and in 

some areas the part of the underlying material below a depth 

of 40 inches is very gravelly. 

Included in this unit are areas of Ashue, Esquatzel, 

Toppenish, and Weirman soils. Also included are areas of 

Zillah soils that have not been artificially drained and areas 

of salt- and alkali-affected soils. 

Permeability of this Zillah soil is moderate. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 24 to 48 

inches from April to November. Runoff is very slow, and the 

hazard of water erosion is slight. The hazard of soil blowing 

is high. The soil is subject to rare periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. Where the unit is drained and protected 

from flooding, the main irrigated crops are asparagus, 

corn, grain, and peas. Grasses and legumes are grown 

for hay, pasture, and seed. 

The main limitations for irrigated crops are wetness and 

the hazard of soil blowing. Dikes can be used to divert 

floodwater. Furrow, corrugation, and sprinkler irrigation 

systems are suited to the soil in this unit. Use of sprinkler 

irrigation permits the even, controlled application of water 

and reduces runoff. To avoid loss of water and leaching of 

plant nutrients from overirrigation, applications of irrigation 

water should be adjusted to the available water capacity, the 

water intake rate, and the crop needs. 

Use of minimum tillage and return of crop residue to the 

soil help to maintain or improve the organic matter content, 

help to maintain tilth, and reduce soil blowing. Using a 

cropping system that includes close-growing, high-residue 

crops in the rotation and using vegetative barriers and 

windbreaks also reduce soil blowing. The soil should be 

protected from soil blowing by maintaining crop residue on 

the surface until the crops are well established in spring. 

Crop rows and irrigation furrows should be established at 

right angles to the prevailing wind where feasible. Mulch can 

be used to stabilize small areas where soil blowing begins. 

This unit is poorly suited to homesite development. The 

main limitations are wetness and the hazard of flooding. 

Flooding can be controlled by use of dikes and channels 

that have outlets to bypass floodwater. Deep drainage 

reduces the problem of wetness. Soil blowing can be a 

problem during construction on large building sites; 

therefore, these sites should be disturbed as little as 

possible. Cutbanks are not stable and are subject to caving 

in. 

The main limitation for septic tank absorption fields is 

wetness, which increases the possibility of failure of septic 

tank absorption fields. If the density of housing is moderate 

to high, community sewage systems are needed to prevent 

contamination of water supplies as a result of seepage. 

This map unit is in capability subclass Ilw. 

192-Zillah silt loam. This very deep, artificially drained 

soil is on flood plains. It formed in recent alluvium. Slope 

is 0 to 2 percent. The native vegetation is mainly watertolerant trees, sedges, and forbs. Elevation is 600 to 1,100 

feet. The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 49 degrees F, 

and the average frost-free season is 130 to 180 days. 

Typically, the surface layer is grayish brown silt loam 

about 12 inches thick. The upper part of the underlying 

material is gray silt loam about 30 inches thick, and the 

lower part to a depth of 60 inches or more is gray loamy 

sand. In some areas the surface layer is sandy loam, and in 

some areas the part of the underlying material below a 

depth of 40 inches is very gravelly. 

Included in this unit are areas of Ashue, Esquatzel, 

Toppenish, and Weirman soils. Also included are areas of 

soils that have not been artificially drained and areas of 

salt- and alkali-affected soils. 

Permeability of this Zillah soil is moderate. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 24 to 48 

inches during the months of April to November. Runoff is 

very slow, and the hazard of water erosion is slight. The soil 

is subject to rare periods of flooding. 

This unit is used for irrigated crops, for wildlife habitat, 

and as homesites. Where the unit is drained and protected 

from flooding, the main irrigated crops are asparagus, 

corn, grain, grapes, and peas. Grasses and legumes are 

grown for hay, pasture, and seed. 

The main limitation for irrigated crops is wetness. Dikes 

can be used to divert floodwater. Furrow, corrugation, and 

sprinkler irrigation systems are suited to the soil in this unit. 

The type of system used depends on the kind of crop 

grown. If surface irrigation systems are used, the risk of 

erosion can be minimized by keeping runs short. Use of 

sprinkler and drip irrigation permits the even, controlled 

application of water, reduces runoff, and minimizes the risk 

of erosion. To avoid loss of water and leaching of plant 

nutrients from overirrigation, 
applications of irrigation water should also be adjusted to the 

available water capacity and the crop needs. 

Proper timing of minimum tillage and return of crop 

residue to the soil reduce compaction, help to maintain or 

improve the organic matter content, help to maintain tilth, 

and improve the water infiltration rate. Using a cropping 

system that includes close-growing, high-residue crops in 

the rotation and maintaining crop residue on the surface 

reduce water erosion. Using vegetated filter strips at the 

end of rows or using sediment ponds, or both, reduces the 

volume of sediment in the tailwater. 

This unit is poorly suited to homesite development. The 

main limitations are wetness and the hazard of flooding. 

Deep drainage reduces wetness. Flooding can be 

controlled by use of dikes and channels that have outlets 

to bypass floodwater. Dustiness can be a problem during 

construction on large building sites; therefore, these sites 

should be disturbed as little as possible. Cutbanks are not 

stable and are subject to caving in. 

The main limitation for septic absorption fields is wetness, 

which increases the possibility of failure of absorption fields. 

If the density of housing is moderate to high, community 

sewage systems are needed to prevent contamination of 

water supplies as a result of seepage. 

This map unit is in capability subclass Ilw, irrigated. 

193-Zillah silt loam, channeled. This very deep, 

somewhat poorly drained soil is in ponded areas on flood 

plains. The soil is dissected by intermittent and perennial 

streams. It formed in recent alluvium. Slope is 0 to 2 

percent. The native vegetation is mainly water-tolerant 

trees, sedges, and forbs. Elevation is 600 to 1,100 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 49 degrees F, and 

the average frost-free season is 130 to 180 days. 

Typically, the surface layer is grayish brown silt loam about 

12 inches thick. The upper part of the underlying material is 

gray silt loam about 30 inches thick, and the lower part to a 

depth of 60 inches or more is gray loamy sand. In some 

areas the surface layer is cobbly or stony, in some areas the 

soil is cobbly or stony throughout, and in some areas the part 

of the underlying material below a depth of 40 inches is very 

gravelly. 

Included in this unit are areas of Ashue, Esquatzel, and 

Weirman soils. 

Permeability of this Zillah soil is moderate. Available water 

capacity is high. Effective rooting depth is limited by a 

seasonal high water table that is at a depth of 0 to 12 

inches from April to November. Runoff is very slow. The 

soil is subject to frequent periods of flooding in spring. 

This unit is used as rangeland and for wildlife habitat. The 

potential native vegetation is mainly basin wildrye, 

tufted hairgrass, sedges, and willows. The main 

limitation 

for the production of forage is wetness. If the range is 

overgrazed, the proportion of preferred forage plants such 

as basin wildrye and bluebunch wheatgrass decreases and 

the proportion of less preferred forage plants increases. 

Areas that are heavily infested with undesirable vegetation 

can be improved by such methods as railing, chaining, 

beating, plowing, chemical treatment, and prescribed 

burning. Range seeding is a suitable practice if the range 

vegetation is in poor condition. The soil in this unit should 

be seeded in fall using a drill. Adapted grasses and 

legumes should be seeded. 

This unit is limited for livestock watering ponds and 

other water impoundments because of the seepage 

potential. Water tanks are a more effective and reliable 

means of storing water for livestock. 

This map unit is in capability subclass VIw, 

nonirrigated. 

prime farmland 

Prime farmland, as defined by the United States 

Department of Agriculture, is the land that is best suited to 

producing food, feed, forage, fiber, and oilseed crops. It 

must either be used for producing food or fiber or be 

available for these uses. It has the soil quality, length of 

growing season, and moisture supply needed to 

economically produce a sustained high yield of crops when it 

is managed properly. Prime farmland produces the highest 

yields with minimal energy and economic resources, and 

farming it results in the least disturbance of the environment.

Prime farmland commonly has an adequate and 

dependable supply of moisture from precipitation or 

irrigation. It also has a favorable temperature and length of 

growing season and an acceptable level of acidity or 

alkalinity. It has few if any rock fragments and is permeable 

to water and air. Prime farmland is not excessively eroded or 

saturated with water for long periods and is not flooded 

during the growing season. The slope is mainly 0 to 5 

percent. Soils that are limited by a high water table, a 

hazard of flooding, or low rainfall may qualify for prime 

farmland if these limitations are overcome by practices such 

as drainage, flood control, or irrigation. Onsite investigation 

is needed to determine the extent of these limitations. 

About 136,000 acres, or nearly 15 percent, of the survey 

area meets the soil requirements for prime farmland if 

irrigated. About 60 percent of this is in general soil map unit 

4, in the east-central part of the area, and minor amounts 

are in map units 1, 7, 8, and 9. In addition, about 37,000 

acres, or nearly 4 percent, of the survey area meets the 

requirements for prime farmland if the soils are adequately 

irrigated, adequately drained, and reclaimed. These soils are 

primarily in map units 4 and 8, in the east-central and 

southern parts of the area. 
Crops grown on the prime farmland in this survey area 

are mainly corn, hops, asparagus, mint, and tree fruit 

such as apples, cherries, peaches, and pears. These 

crops support a sizeable light industry that includes 

processing, storing, and shipping the crops and marketing 

farm supplies. 

A recent trend in land use in some parts of the area has 

been to convert areas of prime farmland to industrial and 

urban areas. The loss of prime farmland to these and other 

uses has made it necessary to farm areas that generally are 

more erodible, droughty, and difficult to cultivate and are less 

productive. 

The following map units meet the requirements for prime 

farmland if irrigated. The practices needed in addition to 

irrigation to overcome the limitations, if any, are shown in 

parentheses after the map unit name. The extent of each 

map unit is given in table 4, the location is given on the 

detailed soil maps in the back of this publication, and the 

soil qualities that affect use and management are described 

in the section "Detailed soil map units." This list does not 

constitute a recommendation for a particular land use. 

2 Ashue loam 

4 Bickleton silt loam, 0 to 5 percent slopes 

10 Burke silt loam, 2 to 5 percent slopes 

18 Cleman very fine sandy loam, 0 to 2 percent 

slopes 

19 Cleman very fine sandy loam, 2 to 5 percent slopes 

24 Cowiche loam, 2 to 5 percent slopes 

32 Esquatzel silt loam, 0 to 2 percent slopes 

33 Esquatzel silt loam, 2 to 5 percent slopes 

46 Harwood loam, 2 to 5 percent slopes 

50 Harwood-Burke-Wiehl silt loams, 2 to 5 percent slopes 

66 Kittitas silt loam (if artificially drained and reclaimed) 

79 Mikkalo silt loam, 0 to 5 percent slopes 

86 Naches loam 

91 Outlook fine sandy loam (if artificially drained 

and reclaimed) 

92 Outlook silt loam (if artificially drained and 

reclaimed) 

97 Renslow silt loam, basalt substratum, 0 to 5 

percent slopes 

99 Ritzville silt loam, 2 to 5 percent slopes 

104 Ritzville silt loam, basalt substratum, 0 to 5 

percent slopes 

124 Scooteney silt loam, 0 to 2 percent slopes 

125 Scooteney silt loam, 2 to 5 percent slopes 

128 Selah silt loam, 2 to 5 percent slopes 

132 Shano silt loam, 2 to 5 percent slopes 

139 Sinloc silt loam, 0 to 2 percent slopes (if 

artificially drained and reclaimed) 

140 Sinloc silt loam, 2 to 5 percent slopes (if 

artificially drained and reclaimed) 

156 Tieton fine sandy loam, 2 to 5 percent slopes 

157 Tieton loam, 0 to 2 percent slopes 

158 Tieton loam, 2 to 5 percent slopes 

163 Toppenish silt loam 

168 Umapine silt loam, 0 to 5 percent slopes (if 

artificially drained and reclaimed) 

169 Umapine silt loam, drained, 0 to 2 percent 

slopes 

170 Umapine silt loam, drained, 2 to 5 percent 

slopes 

172 Warden fine sandy loam, 0 to 2 percent 

slopes 

173 Warden fine sandy loam, 2 to 5 percent 

slopes 

176 Warden silt loam, 0 to 2 percent slopes 

177 Warden silt loam, 2 to 5 percent slopes 

185 Wenas silt loam 

186 Willis fine sandy loam, 2 to 5 percent slopes 

187 Willis silt loam, 2 to 5 percent slopes 

190 Yakima silt loam 

192 Zillah silt loam
use and management of the soils 

This soil survey is an inventory and evaluation of the 

soils in the survey area. It can be used to adjust land uses 

to the limitations and potentials of natural resources and 

the environment. Also, it can help avoid soil-related failures 

in land uses. 

In preparing a soil survey, soil scientists, conservationists, 

engineers, and others collect extensive field data about the 

nature and behavior characteristics of the soils. They 

collect data on erosion, droughtiness, flooding, and other 

factors that affect various soil uses and management. Field 

experience and collected data on soil properties and 

performance are used as a basis in predicting soil behavior. 

Information in this section can be used to plan the use 

and management of soils for crops and pasture; as 

rangeland and woodland; as sites for buildings, sanitary 

facilities, highways and other transportation systems, and 

parks and other recreation facilities; and for wildlife habitat. 

It can be used to identify the potentials and limitations of 

each soil for specific land uses and to help prevent 

construction failures caused by unfavorable soil properties. 

Planners and others using soil survey information can 

evaluate the effect of specific land uses on productivity and 

on the environment in all or part of the survey area. The 

survey can help planners to maintain or create a land use 

pattern in harmony with the natural soil. 

Contractors can use this survey to locate sources of 

sand and gravel, roadfill, and topsoil. They can use it to 

identify areas where bedrock, wetness, slope, or other soil 

features can cause difficulty in excavation. 

Health officials, highway officials, engineers, and 

others may also find this survey useful. The survey can 

help them plan the safe disposal of wastes and locate 

sites for pavements, sidewalks, campgrounds, 

playgrounds, lawns, and trees and shrubs. 

crops and pasture 

Tom Reedy, soil scientist, Soil Conservation Service, prepared this 

section. 

General management needed for crops and pasture is 

suggested in this section. The crops or pasture plants best 

suited to the soils, including some not commonly grown in 

the survey area, are identified; the system of land capability 

classification used by the Soil Conservation Service is 

explained; and the estimated 

yields of the main crops and hay and pasture plants are 

listed for each soil. 

Each area of cropland is a unique combination of soils, 

slopes, elevation, climate, and other characteristics. 

Management should consist of a system that recognizes 

these characteristics. The objective of a cropland 

management system is to maintain or improve the quality of 

the environment; to maintain or improve crop production 

while conserving energy resources; and to protect the soil 

from erosion. 

Management practices that enhance the environment 

may include developing watering facilities, planting 

hedgerows, leaving some standing grain, or establishing 

permanent cover for wildlife in odd areas. Other 

environmental concerns such as properly using pesticides, 

properly disposing of empty containers, trapping sediment in 

debris basins, and properly disposing of animal waste 

should also be considered. 

Management practices that protect the soil from erosion 

also may provide additional environmental, production, or 

energy benefits. Erosion control practices include using an 

adapted crop rotation that may include cover crops, green 

manure crops, or grasses and legumes in the rotation; 

using minimum tillage; using crop residue; stubble 

mulching; seeding early in fall; divided-slope farming; fall 

chiseling; and using terraces, field windbreaks, and 

grassed waterways. 

Planners of management systems for individual fields or 

farms should consider the detailed information given in the 

description of each soil under "Detailed soil map units." 

Specific information can be obtained from the local office 

of the Soil Conservation Service or the Cooperative 

Extension Service. 

Approximately 268,880 acres of this survey area is 

irrigated cropland. A wide variety of crops are grown under 

irrigation, including apples, cherries, peaches, apricots, mint, 

hops, asparagus, sweet corn, corn for silage, grapes, hay 

and pasture, and wheat. Production of crops such as 

irrigated corn, squash, melons, wheat, and potatoes 

fluctuates, depending on the market value of the major 

crops and on the crop rotation system used. About 64,000 

acres of the area is nonirrigated cropland. The main 

nonirrigated crop is winter wheat grown in a wheat-summer 

fallow cropping system. 

The deep, well drained soils in the area that warm up 

early in spring and have a relatively long growing seasonmore than 135 frost-free days-are well suited 
to irrigated orchard and vegetable crops. These soils 

include Esquatzel and Cleman soils on flood plains; 

Cowiche, Ritzville, Shano, and Tieton soils on uplands; and 

Scooteney and Warden soils on terraces. These soils, as 

well as Renslow and Taneum soils, are also well suited to 

nonirrigated small grain. 

Most of the well drained soils in irrigated areas are suited 

to orchard and vegetable crops. Frost control is needed in 

areas of these soils where frosts occur late in spring as a 

result of poor air drainage. Suitable practices for frost control 

include use of orchard heaters, wind machines, and overtree or under-tree sprinklers (5). In these areas it is important, 

especially when replanting, to consider growing fruit trees 

that develop later in spring and thus are less subject to frost 

damage. Whenever possible, trees should be planted up and 

down the slope to allow air to drain freely. 

Most of the crops grown in the survey area respond well 

to nitrogen, phosphorus, and potassium. Ammonium 

nitrate, ammonium sulfate, and urea fertilizers commonly are 

used. Urea fertilizer is most popular and is least expensive 

per unit of nitrogen applied. Periodic applications of lime are 

needed because of the acidifying effect of ammonium 

fertilizer. Where leaching has occurred, applications of boron 

may be needed. Some areas are deficient in zinc, especially 

if they have been leveled. Some areas are low in content of 

sulfur. Some foliar applications of micronutrients are used in 

orchards. 

The soils in the survey area range from slightly acid to 

very strongly alkaline. Soils that are strongly alkaline or very 

strongly alkaline, such as the somewhat poorly drained 

Fiander, Kittitas, Outlook, Sinloc, and Umapine soils 

and the poorly drained Wanser soils, are high in content of 

exchangeable sodium. These soils should be leached with 

elemental sulfur or sulfuric acid if they have an inherently 

high content of free lime. Gypsum is needed if the content of 

free lime is not adequate (22). Because these soils have a 

water table at a relatively shallow depth, provisions for 

improved drainage are needed before the soils are leached. 

For all soils in the survey area, the amount of lime, 

gypsum, fertilizer, and other amendments applied 

should be based on soil tests, on the needs of the crop, 

and on the expected yields. The local office of the 

Cooperative Extension Service can help to determine the 

kind and amount of amendments to apply. 

About 2 percent of the soils in the survey area are 

somewhat poorly drained and have a sufficiently high water 

table that drainage is needed for maximum crop production. 

Many of these wet areas provide critical habitat for wildlife, 

because permanent vegetation has been removed by 

intensive farming in many parts of the survey area. Wet 

areas also provide ground water recharge, serve as 

sinks for sediment and nutrients, store floodwater 

temporarily, and improve the esthetic value of the 

landscape. 

Subsurface drainage systems should be designed 

according to soil permeability, with narrower spacing where 

permeability is less. The amount of water to be drained 

should determine the size of drain pipe and the gradient. All 

drainage systems should be discharged to an acceptable 

drainage course that will not further contribute to surface 

water pollution. The wet soils may need amendments to 

facilitate leaching of excessive sodium. 

Generally, soils relatively high in organic matter content 

have good tilth. As tilth increases, soil erosion and surface 

crusting decrease and the water intake rate increases. 

Therefore, it is important to have crops in the cropping 

system that will maintain or improve the organic matter 

content. This can be done by incorporating as much residue 

as possible into the soil and by rotating high residue crops 

such as grain, grasses, legumes, and corn with low residue 

row crops. To facilitate the decomposition of residue to 

organic matter, adequate nitrogen fertilizer is needed. 

Irrigation water management is the major resource 

conservation concern in irrigated areas. If irrigation water is 

not properly applied, soil erosion results. Erosion is a 

concern because the surface layer, which is the most fertile 

layer in the soil profile and contains most of the organic 

matter and available plant nutrients, is the first to be eroded 

away. With loss of organic matter, the structure of the soil 

deteriorates, available water capacity and the water intake 

rate decrease, and general tilth is lost. Thus, soil erosion 

reduces the productivity of the soil and eventually results in 

pollution of streams by deposition of sediment, nutrients, and 

pesticides. 

If irrigation water is not properly conserved and the rate of 

application is excessive, soil erosion is increased in most 

areas. Wasteful use of water reduces streamflow of the 

Yakima River and compounds water pollution problems in 

most streams in the area. Cropping systems that keep a 

plant cover and residue on the soil during critical periods 

reduce soil erosion. 

Proper irrigation water management and proper use of 

agronomic practices minimize the hazard of erosion. 

Applications of irrigation water should be adjusted to the 

available water capacity, the water intake rate, and the crop 

needs to avoid loss of water and leaching of plant nutrients 

and to minimize erosion. Rotating close-growing crops such 

as grass and alfalfa in the cropping system on sloping soils 

reduces erosion by protecting the soil surface and increasing

the water intake rate. Use of minimum tillage and high 

residue crops such as wheat and corn reduces the amount of

the surface exposed, minimizes sealing of the surface, slows 

runoff, and reduces erosion. Growing cover crops in 

vineyards and orchards during the irrigation season and 

growing mint in meadows also reduce erosion. 

In dryland areas soil blowing and water erosion are 

reduced if fall grain is seeded early, nitrogen is applied, 

stubble mulch tillage is used, fields are stripcropped, and 
tillage is on the contour or across the slope. Chiseling or 

subsoiling the stubble fields in fall on the contour or across 

the slope slows runoff and increases the water intake. 

Terraces and diversions, which are most practical on deep 

and moderately deep soils, reduce the length of slopes and 

thereby reduce runoff and erosion. The shallow Gorst, 

Lickskillet, Moxee, Scoon, and Starbuck soils are not 

suited to dryland cultivation and should be seeded to 

permanent grass. 

Soil blowing is a hazard on the sandy Quincy and Hezel 

soils. If irrigated, these soils should not be left barr

en during 

periods when the soils are susceptible to erosion. Use of 

winter cover crops, strip tillage, and crop residue is needed 

to control soil blowing in spring. Retaining crop residue on 

the surface or using straw, manure, and other material as 

mulch reduces soil blowing, helps to maintain or improve 

organic matter content, and conserves moisture. 

Because of the rapid permeability of the Quincy and Hezel 

soils, the high streamflow needed for water to reach the full 

length of the furrows causes excessive erosion. Therefore, 

the soils are not suited to surface irrigation systems but are 

suited to sprinkler, trickle, or drip systems. Because of the 

droughtiness of these soils, frequent light applications of 

water are needed. Unless irrigated, these soils are poorly 

suited to cultivation. 

Compaction and breakdown of soil structure caused by 

excessive tillage and continuous use of heavy equipment 

are common on the silt loams and loams in the area. These 

also reduce the water intake rate and increase the risk of 

erosion. Soil compaction can be reduced by use of 

minimum tillage, proper timing of tillage in relation to 

moisture content, close-growing crops, and crop residue. 

Tillage pans may be broken up by subsoiling or chiseling 

when the soil is dry. Use of minimum tillage and crop residue 

also helps to maintain soil structure. 

Furrow, corrugation, sprinkler, or drip irrigation 

systems are used in the survey area. Sprinkler and drip 

irrigation systems are suited to all the soils in the survey 

area. These systems permit an even, controlled application of 

irrigation water and, if managed properly, reduce the risk of 

erosion and leaching of plant nutrients. Furrow and 

corrugation systems are used on most soils that have slopes 

of less than 5 percent. Use of surface systems on the 

shallow Gorst, Moxee, Scoon, and Starbuck soils is not 

practical regardless of the slope, because the hazard of 

eroding the furrows is too high. These soils are suited to 

sprinkler, drip, and trickle systems only. Using a cropping 

system that provides continuous plant cover, such as hay 

and pasture, or growing perennial cover crops in 

orchards reduces erosion on these soils. 

yields per acre 

The average yields per acre that can be expected of the 

principal crops under a high level of management are 

shown in table 5. In any given year, yields may be 

higher or lower than those indicated in the table because of 

variations in rainfall and other climatic factors. For those 

soils used as nonirrigated cropland and where a summerfallow cropping system is used, the yields represent the year 

that the soils are cropped. 

The yields are based mainly on the experience and 

records of farmers, conservationists, and extension 

agents. Available yield data from nearby counties and 

results of field trials and demonstrations are also 

considered. 

The management needed to obtain the indicated yields of 

the various crops depends on the kind of soil and the crop. 

Management can include drainage, erosion control, and 

protection from flooding; the proper planting and seeding 

rates; suitable high-yielding crop varieties; appropriate and 

timely tillage; control of weeds, plant diseases, and harmful 

insects; favorable soil reaction and optimum levels of 

nitrogen, phosphorus, potassium, and trace elements for 

each crop; effective use of crop residue, barnyard manure, 

and green-manure crops; and harvesting that insures the 

smallest possible loss. 

For yields of irrigated crops, it is assumed that the 

irrigation system is adapted to the soils and to the crops 

grown, that good quality irrigation water is uniformly applied 

as needed, and that tillage is kept to a minimum. 

The estimated yields reflect the productive capacity of 

each soil for each of the principal crops. Yields are likely to 

increase as new production technology is developed. The 

productivity of a given soil compared with that of other soils, 

however, is not likely to change. 

Crops other than those shown in table 5 are grown in the 

survey area, but estimated yields are not listed because the 

acreage of such crops is small or because yield data were 

not available. The local office of the Soil Conservation 

Service or of the Cooperative Extension Service can provide 

information about the management and productivity of the 

soils. 

land capability classification 

Land capability classification shows, in a general way, the 

suitability of soils for most kinds of field crops. Crops that 

require special management are excluded. The soils are 

grouped according to their limitations for field crops, the risk 

of damage if they are used for crops, and the way they 

respond to management. The grouping does not take into 

account major and generally expensive landforming that 

would change slope, depth, or other characteristics of the 

soils, nor does it consider possible but unlikely major 

reclamation projects. Capability classification is not a 

substitute for interpretations designed to show suitability and 

limitations of groups of soils for rangeland, for woodland, and 

for engineering purposes. 

In the capability system, soils are generally grouped at 

three levels: capability class, subclass, and unit. Only class 

and subclass are used in this survey. These levels are 

defined in the following paragraphs. 
Capability classes, the broadest groups, are designated 

by Roman numerals I through VIII. The numerals indicate 

progressively greater limitations and narrower choices 

for practical use. The classes are defined as follows: 

Class I soils have slight limitations that restrict their 

use. 

Class II soils have moderate limitations that reduce the 

choice of plants or that require moderate conservation 

practices. 

Class III soils have severe limitations that reduce the 

choice of plants or that require special conservation 

practices, or both. 

Class IV soils have very severe limitations that reduce the 

choice of plants or that require very careful management, or 

both. 

Class V soils are not likely to erode but have other 

limitations, impractical to remove, that limit their use. 

Class Vi soils have severe limitations that make them 

generally unsuitable for cultivation. 

Class VII soils have very severe limitations that make 

them unsuitable for cultivation. 

Class VIII soils and miscellaneous areas have 

limitations that nearly preclude their use for commercial crop 

production. 

Capability subclasses are soil groups within one class. 

They are designated by adding a small letter, e, w, s, or c, to 

the class numeral, for example, Ile. The letter e shows that 

the main limitation is risk of erosion unless close-growing 

plant cover is maintained; w shows that water in or on the 

soil interferes with plant growth or cultivation (in some soils 

the wetness can be partly corrected by artificial drainage); s 

shows that the soil is limited mainly because it is 

shallow, droughty, or stony; and c, used in only some 

parts of the United States, shows that the chief limitation is 

climate that is very cold or very dry. 

In class I there are no subclasses because the soils of this 

class have few limitations. Class V contains only the 

subclasses indicated by w, s, or c because the soils in class 

V are subject to little or no erosion. They have other 

limitations that restrict their use to pasture, rangeland, 

woodland, wildlife habitat, or recreation. 

The capability classification of each map unit is given in 

the section "Detailed soil map units." 

rangeland 

By Richard A. Pudney, range conservationist, Soil 

Conservation Service. 

Approximately 48 percent, or about 425,456 acres, of the 

Yakima County Area is rangeland. Cow-calf-steer 

operations are dominant in the area. Although 

individual operations vary, the livestock commonly are 

grazed at lower elevations in spring and then are moved to 

the foothills early in summer. Later, the livestock are 

transported to the mountainous areas, where they 

remain in summer and early in fall. Then they are 

returned to stubble fields and feedlots for the winter. 

Many livestock operations are run in combination with 

nonirrigated and irrigated farming. The farm and livestock 

operations vary from growing crops to provide feed for 

livestock in winter to farming operations in which livestock 

are used to graze odd areas, stubble fields or other crop 

aftermath. 

Forage production is influenced by the amount of 

precipitation, length of the growing season, and the 

available water capacity of the soil. Areas at lower 

elevations receive less precipitation and are fairly low in 

forage production. As elevation increases, production also 

increases unless it is limited by a short growing season. 

The available water capacity varies at both low and high 

elevations. Shallow soils have less available water capacity 

and produce less forage than do deep soils, which generally 

have a high available water capacity. 

In areas that have similar climate and topography, 

differences in the kind and amount of vegetation produced 

on rangeland are closely related to the kind of soil. Effective 

management is based on the relationship between the soils 

and vegetation and water. 

Table 6 shows, for each soil, the range site; the total 

annual production of vegetation in favorable, normal, and 

unfavorable years; the characteristic vegetation; and the 

average percentage of each species. Only those soils that 

are used as rangeland are listed. Explanation of the column 

headings in table 6 follows. 

A range site is a distinctive kind of rangeland that 

produces a characteristic natural plant community that differs 

from natural plant communities on other range sites in kind, 

amount, and proportion of range plants. The relationship 

between soils and vegetation was established during this 

survey; thus, range sites generally can be determined directly 

from the soil map. Soil properties that affect moisture supply 

and plant nutrients have the greatest influence on the 

productivity of range plants. Soil reaction, salt content, and a 

seasonal high water table are also important. 

Total production is the amount of vegetation that can be 

expected to grow annually on well managed rangeland that 

is supporting the potential natural plant community. It 

includes all vegetation, whether or not it is palatable to 

grazing animals. It includes the current year's growth of 

leaves, twigs, and fruits of woody plants. It does not include 

the increase in stem diameter of trees and shrubs. It is 

expressed in pounds per acre of air-dry vegetation for 

favorable, normal, and unfavorable years. In a favorable 

year, the amount and distribution of precipitation and the 

temperatures make growing conditions substantially better 

than average. In a normal year, growing conditions are about 

average. In an unfavorable year, growing conditions are well 

below average, generally because of low available soil 

moisture. 
Dry weight is the total annual yield per acre reduced to a 

common percent of air-dry moisture. 

Characteristic vegetation-the grasses, forbs, and shrubs 

that make up most of the potential natural plant community on 

each soil-is listed by common name. Under composition, the 

expected percentage of the total annual production is given for 

each species making up the characteristic vegetation. The 

amount that can be used as forage depends on the kinds of 

grazing animals and on the grazing season. 

Range management requires a knowledge of the kinds of 

soil and of the potential natural plant community. It also requires 

an evaluation of the present range condition. Range condition 

is determined by comparing the present plant community with 

the potential natural plant community on a particular range site. 

The more closely the existing community resembles the potential

community, the better the range condition. Range 

condition is an ecological rating only. It does not have a 

specific meaning that pertains to the present plant community 

in a given use. 

The objective in range management is to control grazing so 

that the plants growing on a site are about the same in kind 

and amount as the potential natural plant community for that 

site. Such management generally results in the optimum 

production of vegetation, reduction of undesirable brush 

species, conservation of water, and control of water erosion 

and soil blowing. Sometimes, however, a range condition 

somewhat below the potential meets grazing needs, provides 

wildlife habitat, and protects soil and water resources. 

The basic soil and plant resources in the survey area can be 

maintained or improved through proper management. Among 

the range management practices important for all rangeland in 

the area are proper grazing use and planned grazing systems, 

which include deferred grazing, proper season of use, and good 

distribution of grazing. Distribution of grazing can be accomplished 

by proper placement of watering facilities and salt and by 

fencing where needed. The suitability of range improvement 

practices such as brush management, range seeding, and use 

of pipelines depends on the characteristics of a given site. 

Livestock graze selectively; they seek out the palatable and 

nutritious plants and graze them intensively. Without proper 

grazing management, these preferred plants are depleted. As 

the preferred plants decrease, less palatable plants increase. If 

poor grazing management is continued, the less palatable 

plants are depleted by livestock and unpalatable grasses, 

weeds, shrubs, and annual plants invade. Rangeland that is 

dominated by these plants produces only a fraction of the 

usable forage it is capable of producing and supports far fewer 

livestock than it potentially can support. 

Sound range management consists of practices such as 

balancing the requirements of livestock and wildlife 

with the forage available, proper grazing use and distribution, 

and periodically resting the preferred and less palatable 

vegetation from grazing during the growing season. 

In determining how many animals an area can support, it is 

essential to know how much of the area will be used by the 

animals. Stock water is often a key factor. Livestock in the 

more nearly level areas generally make good use of 

vegetation that is as much as 1 mile from water, but in 

extremely steep areas they may not travel more than one-fourth 

of a mile from water. Development of stock water in underused 

areas improves the use of the forage in these areas and reduces 

use in overgrazed areas. Placing salt blocks in undergrazed 

areas also helps to entice livestock away from overused 

areas and to improve use in isolated areas. Cross fencing is 

another good way to improve livestock distribution, but it should be 

used in combination with stock water developments and other 

management practices. 

Periodic rest from grazing during the growing season 

allows the preferred and less palatable vegetation to build 

up its root reserves and to improve its vigor and production. 

Various deferred-rotation grazing systems can be developed 

to insure that each pasture gets periodic rest from grazing 

during the growing season. Rotation grazing systems can 

also be tailored to meet the needs of any ranching operation. 

Proper grazing use is essential in any grazing operation. 

Enough of the plant must be left following grazing to allow the 

plant to continue to manufacture its own food. This process, 

called photosynthesis, depends on the leaves of the plant to 

absorb carbon dioxide, an essential element in the process. 

When all leaves are removed by close grazing, the plant has to 

use the food reserves stored in its root system to continue to 

grow and survive. If a plant is continuously overgrazed, its store 

of food in the root system will eventually run out and the plant will 

die. Proper grazing use insures that the plants can continue to 

manufacture food. Good management leads to productive, 

healthy forage plants that have root systems strong enough to 

survive through unfavorable years. 

woodland management and 

productivity 

By Ronald A. Peyton, forester, Soil Conservation Service. 

About 133,800 acres, or 15 percent, of the survey area is 

forested. Most of this land is in privately owned commercial 

holdings. The area has 10 distinct forest cover types (20). The 

major forest cover types that have commercial value are interior 

ponderosa pine, interior Douglas-fir, grand fir-larch-Douglas-fir, 

and ponderosa pine-larch-Douglas-fir. The minor forest cover 

types include Englemann spruce-subalpine fir, lodgepole pine, 

whitebark pine, western larch-Douglas-fir, black cottonwoodwillow, and Oregon white oak. 
Moisture and topography generally dictate the character 

of the forests in the survey area (11). Along the eastern 

fringe of the forest land, timber stands are scattered and 

occur mainly as narrow bands on canyon bottoms and along 

canyonsides. These meandering strips of timber merge into 

sparse stands of ponderosa pine and Oregon white oak, 

which are adjacent to denser stands of mixed species in the 

higher lying, more moist areas. As a result, a large portion of 

the timber is along a band 30 miles wide that is east of the 

crest of the Cascade Range. 

Forest management in the survey area ranges from little 

if any management to intensive cultural practices such as 

fertilization and precommercial and commercial thinning on 

a preset time schedule. Present stands vary widely in 

species, age, and size distribution. Selective harvesting of 

old growth, high-quality ponderosa pine and Douglas-fir has 

contributed to this heterogeneous nature of the stands. In 

addition, the regular occurrence of wildfire has produced 

numerous areas that are densely stocked with lodgepole 

pine and western larch. Many of the lodgepole pine stands 

in the area are overstocked, and reduced yields may be a 

concern in these areas unless some thinning is done. 

Many kinds of insects and disease attack forest trees in 

this area (6,12). The damage they do varies from year to year 

(8). Normally, losses are confined to individual trees or to 

scattered stands; however, insect populations increase 

occasionally, and large numbers of trees are damaged or 

killed. 

The most damaging insect in the area has been the 

mountain pine beetle (Dendroctonus ponderosae), which 

attacks lodgepole pine, western white pine, and young 

stands of ponderosa pine. The Douglas-fir beetle 

(Dendroctonus pseudotsugae), silver fir beetle 

(Pseudohylesinus sericeus), and western pine beetle 

(Dendroctonus brevicomis) have also caused extensive 

damage. Several other insects are becoming major problems 

in the area. The western spruce budworm (Choristoneura 

occidentalis) is highly destructive to Douglas-fir, western 

larch, grand fir, subalpine fir, and Englemann spruce. The 

Douglas-fir tussock moth (Orgyia pseudotsugata) can cause 

widespread defoliation. Outbreaks of the moth develop 

explosively and after about 3 years subside abruptly. The 

balsam woolly aphid (Adelges piceae) has become widely 

established and is highly destructive to Pacific silver fir, 

subalpine fir, and grand fir (16). 

Dwarf mistletoe (Arceuthobium) is widespread in the survey 

area and is a major factor in tree mortality and volume loss. 

This parasite attacks pines, Douglas-fir, and western larch of 

all ages. Control of dwarf mistletoe is difficult and costly, but 

removal of infected trees during harvesting can reduce 

spread of the disease. Many other diseases such as root rot, 

heart rot, needle scale, and rust are present and may be 

serious in a given locality. 

Douglas-fir and ponderosa pine provide about 55 

percent of the available sawtimber in the area, true firs 

about 25 percent, western larch and hemlock each about 7 

percent, and lodgepole pine about 4 percent. Normal 

mortality is a continuous problem, and it results in a 

considerable volume of salvable deadwood. The lack of 

concentrated volumes, however, often makes harvesting 

economically unfeasible. Historically, the forest industry in 

the survey area has been oriented primarily to sawn 

products. Product diversification and changing economics 

are now providing markets for smaller logs and minor 

species. 

Soils vary in their ability to produce trees and in the 

limitations and hazards associated with harvesting them. 

Depth, fertility, texture, and the available water capacity of 

soils are among the factors that influence tree growth. 

Elevation, aspect, and climate determine the kinds of trees 

that can be expected to grow on any site, especially in 

mountainous areas. Each map unit in the section "Detailed 

soil map units" suitable for producing wood crops gives 

information concerning woodland productivity, limitations for 

harvesting timber, concerns for producing timber, and 

common forest understory plants. 

Table 7 can be used by woodland owners or forest 

managers in planning the use of soils for wood crops. Only 

those soils suitable for wood crops are listed. The table lists 

the ordination (woodland suitability) symbol for each soil. 

Soils assigned the same ordination symbol require the same 

general management and have about the same potential 

productivity. 

The first part of the ordination symbol, a number, 

indicates the potential annual production of wood fiber. It is 

expressed in terms of cubic meters per hectare per year for 

an indicator tree species. The number 1 indicates a potential 

production of 1 cubic meter per hectare per year, number 2 

indicates a potential production of 2 cubic meters per 

hectare per year, and so on. A mean annual increment of 1 

cubic meter per hectare equals about 14.3 cubic feet per 

acre. Yields in cubic meters are computed at the 

culmination of the mean annual increment for the first 

species listed under common trees. These yields are 

reduced as appropriate when the stocking of the basal area 

is consistently below normal (13,14). 

The second part of the symbol, a letter, indicates the 

major kind of soil limitation. The letter a indicates that 

limitations or restrictions are insignificant. The letter c 

indicates that clay is in the upper part of the soil; d, 

restricted rooting depth; f, high content of coarse 

fragments in the soil profile; r, steep slopes; s, sandy 

texture; t, toxic substances in the soil; w, excessive water 

in or on the soil; and x, a large amount of stones on the 

surface or rock outcroppings. If a soil has more than one 

limitation, priority in placing the soil into a limitation class is 

as follows: x, w, t, d, c, s, f, and r. 
In table 7 the soils are also rated for a number of 

factors to be considered in woodland management. slight, 

moderate, and severe are used to indicate the degree of 

the major soil limitations. 

Equipment limitation ratings refer to the limits placed on 

the year-round or seasonal use of equipment. A rating of 

slight indicates that equipment use normally is not restricted 

to a particular kind of equipment or time of year because of 

soil or climatic factors. Moderate indicates a short seasonal 

limitation because of soil wetness, a fluctuating water table, 

or some other factor. Severe indicates a seasonal limitation, 

a need for special equipment such as a cable-yarding logging 

system, or a limitation in the use of equipment. 

Steepness of slope and soil wetness are the main factors 

that cause equipment limitations. As slope gradient and 

length increase, use of wheeled equipment becomes more 

difficult. On steeper slopes tracked equipment must be used. 

On the steepest slopes, even tracked equipment cannot be 

operated safely and more sophisticated systems must be 

used. Soil wetness, especially where the soil material is fine 

textured, can severely limit the use of equipment and make 

harvesting practical only during the dry period in summer. 

Seedling mortality ratings refer to the probability of death 

of naturally occurring or planted tree seedlings of the 

principal species on the soils. Plant competition is not 

considered in the ratings. The ratings apply to seedlings from 

good stock that is properly planted or germinates naturally 

during a period of sufficient soil moisture. Slight indicates no 

problem is expected under normal conditions. Moderate 

indicates some problems of mortality can be expected and 

extra precautions are advisable. Severe indicates that 

mortality will be high, replanting may be necessary, and extra 

precautions are essential for successful reforestation. Soil 

wetness; droughtiness of the surface layer, especially on 

south- or southwest-facing slopes; limited rooting depth; the 

kind of soil texture; and the conditions on ridgetops account 

for most seedling mortality problems. To offset these 

limitations, larger than normal planting stock, special site 

preparation, surface drainage, or reinforcement 

planting may be needed. 

Windthrow hazard ratings consider the soil characteristics 

that affect the development of tree roots and the ability of 

the soil to hold tree roots firmly. A rating of slight indicates 

that trees normally are not blown down by wind; strong 

winds may break trees but not uproot them. Moderate 

indicates that few trees may be blown down during periods 

of excessive soil wetness and strong winds. Severe indicates 

that many trees may be blown down during periods of 

excessive soil wetness and moderate or strong winds. 

Restricted rooting depth because of a high water table, 

underlying bedrock, or an impervious layer and poor 

anchoring of roots because of the sandy texture of the 

surface layer and subsoil are responsible for most 

windthrow problems. Moderate and 

severe ratings indicate the need for more care in thinning 

the edges of woodland stands, periodic salvage of 

windthrown trees, and an adequate road and trail system to 

allow for salvage operations. 

Plant competition ratings refer to the likelihood of the 

invasion or growth of undesirable species when openings are 

made in the tree canopy. The invading plants compete with 

naturally established or planted seedlings for available 

growing space and hinder the development of a fully stocked 

stand of desirable trees. In areas that have low annual 

precipitation or limited rainfall during the growing season, 

generally on the eastern fringe of the forested zones, plants 

compete for the limited amount of available soil moisture. A 

slight rating indicates that desirable plants are not likely to 

delay the development of natural reforestation and that 

planted tree seedlings have good potential for development 

without excessive competition. Moderate indicates that 

competition will delay natural or planted reforestation. 

Severe indicates that competition will prevent natural or 

planted reforestation. In many cases, the key to predicting 

plant competition problems is the quantity and proximity of 

seed sources of undesirable plants. Moderate and severe 

ratings indicate the need for careful and thorough clean-up 

after harvesting in preparation for reforestation and for use 

of mechanical or chemical treatment to retard growth of 

competing plants and allow tree seedlings to develop. 

The potential productivity of common trees on a soil is 

expressed as a site index. This index is determined by taking 

height and age measurements on selected trees within 

stands of a given species. The procedure for doing this is 

given in the appropriate site index tables. The site index 

applies to fully stocked, even-aged, unmanaged stands 

growing on a particular soil. The highest timber yields can be 

expected from soils that have the highest site indexes. 

Site index values can be converted into estimated yields 

of trees at various ages by using the applicable yield tables. 

In this survey area, USDA Technical Bulletin 630 (15) was 

used to determine the site index and yield estimates for 

ponderosa pine and for inland Douglas-fir. For lodgepole 

pine the site indexes are based on work by Alexander (3) 

and yields on work by Myers (17). Site indexes and yields for 

western larch are based on work by Schmidt (18). Site 

indexes for Englemann spruce and subalpine fir are based 

on tables by Alexander (4), and yield estimates are provided 

by Edminster (9). Estimates of site indexes for grand fir were 

based on data from the Washington State Department of 

Natural Resources (24); estimates of yield were not 

available. Common trees are listed in the same order as that 

of their general occurrence observed in the soil map unit. 

Trees to plant are those that are used for reforestation or, 

if suitable conditions exist, are favored for natural 

regeneration. Species listed are suited to the soils and to 

commercial wood production. The growth rate and wood 
quality of species vary, which influences their economic 

value and marketability. The desired product, 

topographic position, seedling availability, and personal 

preference are factors that can influence the choice of 

trees to use for reforestation. 

woodland understory vegetation 

Nearly all of the 138,000 acres of woodland in the survey 

area is grazable and is extremely important for both wildlife 

and livestock. Many species of wildlife use the woodland as 

range in summer and winter, and many livestock operations, 

both cattle and sheep, depend on it for grazing in summer 

and early in fall. 

The woodland understory plant communities are 

ponderosa pine-shrub-grass at the lower elevations, 

Douglas-fir-pinegrass at the intermediate elevations, 

and subalpine fir-huckleberry at the higher elevations. 

Management practices applicable to grazable 

understory are discussed in the section "Rangeland." 

The quantity and quality of understory vegetation vary 

with the kind of soil, the age and kind of trees in the 

canopy, the density of the canopy, and the depth and 

condition of the litter. The density of the canopy determines 

the amount of light that understory plants receive. 

Table 8 shows, for each soil suitable for woodland use, 

the potential for producing understory vegetation. The total 

production of understory vegetation includes the herbaceous 

plants and the leaves, twigs, and fruit of woody plants up to 

a height of 4 1/2 feet. It is expressed in pounds per acre of 

air-dry vegetation in favorable, normal, and unfavorable 

years. In a favorable year, soil moisture is above average 

during the optimum part of the growing season; in a normal 

year, it is below average. 

Table 8 also lists the common names of the 

characteristic vegetation on each soil and the percentage 

composition, by air-dry weight, of each kind of plant. The 

table shows the kind and percentage of understory plants 

expected under a canopy density that is most nearly typical 

of woodland in which the production of wood crops is 

highest. 

windbreaks and environmental 

plantings 

Windbreaks protect livestock, buildings, and yards 

from wind and snow. They also protect fruit trees and 

gardens, and they furnish habitat for wildlife. Several rows 

of low- and high-growing broadleaf and coniferous trees 

and shrubs provide the most protection. 

Field windbreaks are narrow plantings made at right 

angles to the prevailing wind and at specific intervals across 

the field. The interval depends on the erodibility of the soil. 

Field windbreaks protect cropland and crops from wind, hold 

snow on the fields, and provide food and cover for wildlife. 

Environmental plantings help to beautify and screen 

houses and other buildings and to abate noise. The plants, 

mostly evergreen shrubs and trees, are closely spaced. To 

insure plant survival, a healthy planting stock of suitable 

species should be planted properly on a well prepared site 

and maintained in good condition. 

Table 9 shows the height that locally grown trees and 

shrubs are expected to reach in 20 years on various soils. 

The estimates in table 9 are based on measurements and 

observation of established plantings that have been given 

adequate care. They can be used as a guide in planning 

windbreaks and screens. For those soils not listed in this 

table, the low average annual precipitation or soil 

droughtiness is considered to be too severe for windbreak 

establishment or survival; however, a few of the soils may 

be suitable for windbreaks if irrigated. Additional information 

on planning windbreaks and screens and planting and caring 

for trees and shrubs can be obtained from local offices of 

the Soil Conservation Service or the Cooperative Extension 

Service or from a nursery. 

recreation 

The soils of the survey area are rated in table 10 

according to limitations that affect their suitability for 

recreation. The ratings are based on restrictive soil features, 

such as wetness, slope, and texture of the surface layer. 

Susceptibility to flooding is considered. Not considered in the 

ratings, but important in evaluating a site, are the location 

and accessibility of the area, the size and shape of the area 

and its scenic quality, vegetation, access to water, potential 

water impoundment sites, and access to public sewerlines. 

The capacity of the soil to absorb septic tank effluent and 

the ability of the soil to support vegetation are also 

important. Soils subject to flooding are limited for recreation 

use by the duration and intensity of flooding and the season 

when flooding occurs. In planning recreation facilities, onsite 

assessment of the height, duration, intensity, and frequency 

of flooding is essential. 

In table 10, the degree of soil limitation is expressed as 

slight, moderate, or severe. Slight means that soil properties 

are generally favorable and that limitations are minor and 

easily overcome. Moderate means that limitations can be 

overcome or alleviated by planning, design, or special 

maintenance. Severe means that soil properties are 

unfavorable and that limitations can be offset only by costly 

soil reclamation, special design, intensive maintenance, 

limited use, or by a combination of these measures. 

The information in table 10 can be supplemented by 

other information in this survey, for example, 

interpretations for septic tank absorption fields in table 13 

and interpretations for dwellings without basements and 

for local roads and streets in table 12. 
Camp areas require site preparation such as shaping and 

leveling the tent and parking areas, stabilizing roads and 

intensively used areas, and installing sanitary facilities and 

utility lines. Camp areas are subject to heavy foot traffic and 

some vehicular traffic. The best soils have mild slopes and 

are not wet or subject to flooding during the period of use. 

The surface has few or no stones or boulders, absorbs 

rainfall readily but remains firm, and is not dusty when dry. 

Strong slopes and stones or boulders can greatly increase 

the cost of constructing campsites. 

Picnic areas are subject to heavy foot traffic. Most 

vehicular traffic is confined to access roads and parking 

areas. The best soils for picnic areas are firm when wet, are 

not dusty when dry, are not subject to flooding during the 

period of use, and do not have slopes or stones or boulders 

that increase the cost of shaping sites or of building access 

roads and parking areas. 

Playgrounds require soils that can withstand intensive 

foot traffic. The best soils are almost level and are not wet 

or subject to flooding during the season of use. The surface 

is free of stones and boulders, is firm after rains, and is not 

dusty when dry. If grading is needed, the depth of the soil 

over bedrock or a hardpan should be considered. 

Paths and trails for hiking, horseback riding, and 

bicycling should require little or no cutting and filling. The 

best soils are not wet, are firm after rains, are not dusty when 

dry, and are not subject to flooding more than once a year 

during the period of use. They have moderate slopes and few 

or no stones or boulders on the surface. 

Golf fairways are subject to heavy foot traffic and some 

light vehicular traffic. Cutting or filling may be required. The 

best soils for use as golf fairways are firm when wet, are not 

dusty when dry, and are not subject to prolonged flooding 

during the period of use. They have moderate slopes and no 

stones or boulders on the surface. The suitability of the soil 

for tees or greens is not considered in rating the soils. 

wildlife habitat 

By Donna L. Storch, range conservationist, and Ivan L. 

Lines, Jr., biologist, Soil Conservation Service. 

Soils affect the kind and amount of vegetation that is 

available to wildlife as food and cover. They also affect the 

construction of water impoundments. The kind and 

abundance of wildlife depend largely on the amount and 

distribution of food, cover, and water. Wildlife habitat can be 

created or improved by planting appropriate vegetation, by 

maintaining the existing plant cover, or by promoting the 

natural establishment of desirable plants. 

In table 11, the soils in the survey area are rated 

according to their potential for providing habitat for various 

kinds of wildlife. This information can be used in planning 

parks, wildlife refuges, nature study areas, and 

other developments for wildlife; in selecting soils that are 

suitable for establishing, improving, or maintaining 

specific elements of wildlife habitat; and in determining the 

intensity of management needed for each element of the 

habitat. 

Many of the soils in this survey area are used as irrigated 

cropland, nonirrigated cropland, or rangeland, or as all of 

these. If any areas of a given soil are used as irrigated 

cropland, the ratings for that soil given in table 11 are those 

applicable to irrigated cropland. Otherwise, the soil is rated 

as nonirrigated cropland or as rangeland. Refer to the 

appropriate map unit in the section 

"Detailed soil map units" to determine if some areas of a soil 

are used as irrigated cropland. 

The potential of the soil is rated good, fair, poor, or very 

poor. A rating of good indicates that the element or kind of 

habitat is easily established, improved, or maintained. Few 

or no limitations affect management, and satisfactory results 

can be expected. A rating of fair indicates that the element 

or kind of habitat can be established, improved, or 

maintained in most places. Moderately intensive 

management is required for satisfactory results. A rating of 

poor indicates that limitations are severe for the designated 

element or kind of habitat. Habitat can be created, improved, 

or maintained in most places, but management is difficult 

and must be intensive. A rating of very poor indicates that 

restrictions for the element or kind of habitat are very severe 

and that unsatisfactory results can be expected. Creating, 

improving, or maintaining habitat is impractical or 

impossible. 

The elements of wildlife habitat are described in the 

following paragraphs. 

Grain and seed crops are domestic grains and seedproducing herbaceous plants. Soil properties and features 

that affect the growth of grain and seed crops are depth of 

the root zone, texture of the surface layer, available water 

capacity, wetness, slope, surface stoniness, and flood 

hazard. Soil temperature and soil moisture are also 

considerations. Examples of grain and seed crops are corn, 

wheat, oats, and barley. 

Grasses and legumes are domestic perennial grasses and 

herbaceous legumes. Soil properties and features that affect 

the growth of grasses and legumes are depth of the root 

zone, texture of the surface layer, available water capacity, 

wetness, surface stoniness, flood hazard, and slope. Soil 

temperature and soil moisture are also considerations. 

Examples of grasses and legumes are fescue, crested 

wheatgrass, orchardgrass, clover, and alfalfa. 

Wild herbaceous plants are native or naturally established 

grasses and forbs, including weeds. Soil properties and 

features that affect the growth of these plants are depth of 

the root zone, texture of the surface layer, available water 

capacity, wetness, surface stoniness, and flood hazard. Soil 

temperature and soil moisture are also considerations. 

Examples of wild 
herbaceous plants are bluebunch wheatgrass, 

needlegrass, pigweed, mustard, cheatgrass, filaree, 

and sedges. 

Hardwood trees and woody understory produce nuts or 

other fruit, buds, catkins, twigs, bark, and foliage. Soil 

properties and features that affect the growth of hardwood 

trees and shrubs are depth of the root zone, and available 

water capacity, and wetness. Examples of these plants are 

oak, poplar, cherry, sweetgum, apple, hawthorn, dogwood, 

hickory, blackberry, and blueberry. Examples of fruitproducing shrubs that are suitable for planting on soils rated 

good are Russian-olive, autumn-olive, and crabapple. 

Coniferous plants furnish browse, seeds, and cones. Soil 

properties and features that affect the growth of coniferous 

trees, shrubs, and ground cover are depth of the root zone, 

available water capacity, and wetness. Examples of 

coniferous plants are pine, spruce, fir, and larch. 

Shrubs are bushy woody plants that produce fruit, buds, 

twigs, bark, and foliage. Soil properties and features that 

affect the growth of shrubs are depth of the root zone, 

available water capacity, salinity, and soil moisture. 

Examples of shrubs are Russian-olive, dogwood, bitterbrush, 

snowberry, and sagebrush. 

Wetland plants are annual and perennial wild herbaceous 

plants that grow on moist or wet sites. Submerged or 

floating aquatic plants are excluded. Soil properties and 

features affecting wetland plants are texture of the surface 

layer, wetness, reaction, salinity, slope, and surface 

stoniness. Examples of wetland plants are smartweed, 

wild millet, saltgrass, rushes, sedges, and cattails. 

Shallow water areas have an average depth of less than 5 

feet. Some are naturally wet areas. Others are created by 

dams, levees, or other water-control structures. Soil 

properties and features affecting shallow water areas are 

depth to bedrock, wetness, surface stoniness, slope, and 

permeability. Examples of shallow water areas are marshes, 

waterfowl feeding areas, and ponds. 

The habitat for various kinds of wildlife is described in the 

following paragraphs. 

Habitat for openland wildlife consists of cropland, pasture, 

meadows, and areas that are overgrown with grasses, 

herbs, shrubs, and vines. These areas produce grain 

and seed crops, grasses and legumes, and wild herbaceous 

plants. The wildlife attracted to these areas include 

California quail, pheasant, meadowlark, skunk, 

cottontail, and raccoon. 

Habitat for woodland wildlife consists of areas of 

deciduous plants or coniferous plants or both and 

associated grasses, legumes, and wild herbaceous 

plants. Wildlife attracted to these areas include ruffed 

grouse, thrushes, woodpeckers, songbirds, 

squirrels, raccoon, deer, and elk. 

Habitat for wetland wildlife consists of open, marshy or 

swampy shallow water areas. Some of the wildlife attracted to 

such areas are ducks, geese, herons, redwing blackbird, 

kingfisher, muskrat, and beaver. 

Habitat for rangeland wildlife consists of areas of shrubs 

and wild herbaceous plants. Wildlife attracted to rangeland 

include mule deer, sage grouse, meadowlark, coyote, and 

chukar. 

In the following paragraphs use and management of the 

general soil map units for wildlife habitat are discussed. 

T he survey area has a wide variety of soils, landforms, 

precipitation zones, and vegetation. Elevation ranges from 

600 feet to more than 7,000 feet. Precipitation ranges from 6 

to 50 inches. The vegetation includes grasses and shrubs in 

areas of arid land, irrigated and nonirrigated crops, and 

subalpine forest. Thus, the area provides habitat that 

supports many kinds of wildlife. 

Most of the grass-shrub type of vegetation originally in 

general soil map units 1 to 5 has been replaced by 

intensively farmed irrigated crops. These units provide habitat 

for quail, pheasant, dove, rabbit, and waterfowl as well as for 

numerous nongame birds and mammals. Map units 1 and 2 

include numerous wetlands that provide valuable habitat for 

waterfowl, wading birds, and other wetland wildlife. The large 

trees in the vicinity of wetlands and streams provide valuable 

perches and nesting sites for hawks and owls and for cavity 

nesting birds such as woodpeckers and bluebirds. Areas of 

farmland that are interspersed with wooded streambanks, 

wetlands, vegetated irrigation ditches, and patches of 

noncultivated land still support good populations of wildlife. 

Habitat can be maintained or improved in most areas by 

leaving the cover undisturbed along fence rows, in ditches, 

and in areas of wetland and by planting hedgerows, 

windbreaks, and herbaceous cover on noncultivated or 

eroding land. 

The upland soils in general soil map units 6 to 11 are 

used as rangeland, for orchards, and as cropland. These 

units provide habitat for the kinds of wildlife normally present 

on cropland as well as for rangeland wildlife such as chukar, 

mule deer, coyote, bighorn sheep, and wintering elk. Bighorn 

sheep and wintering elk are mainly on map units 9, 10, and 

11. The orchards and cropland support more wildlife if the 

noncultivated areas are maintained in woody or herbaceous 

cover. Properly grazed pastures also provide food and cover. 

Pesticides should be used sparingly in these areas. 

The carrying capacity for rangeland wildlife is greatest in 

those areas that have not been overgrazed. At some stage 

of their life cycle, most species of rangeland wildlife are 

dependent on the presence of woody and herbaceous 

vegetation that is adjacent to streams or other wet areas. The 

key to maintaining an abundance of rangeland wildlife is to 

protect the native vegetation from overgrazing, burning, 

spraying, or other disturbance particularly in riparian zones. 

Species such as quail and 
chukar will benefit from the development of wildlife 

watering facilities. 

The timbered soils at the higher elevations in general soil 

map units 12 and 13 provide habitat for elk, deer, bear, forest 

grouse, and numerous nongame birds and mammals. These 

areas are the summer range as well as the calving and 

fawning areas for elk and deer. Cliffs and rocky ledges are 

preferred nesting sites for eagles, falcons, and other birds of 

prey. Snags provide nesting and perching sites for birds of 

prey and for cavity nesting birds such as bluebirds and 

woodpeckers. As in other areas, undisturbed vegetation 

along streams provides important habitat necessary for the 

well-being of many species. 

Grazing in wooded areas should be managed to 

accommodate the forage needs of wildlife and to protect 

riparian zones. Logging should be done in small, irregularly 

shaped patches. Snags and riparian zones should be 

protected from logging activities. To reduce soil erosion and 

provide food and cover for wildlife, areas that are logged or 

burned should be seeded to grasses and legumes. After 

logging has been completed, unneeded roads should be 

closed and reseeded to prevent undue disturbance to 

wildlife, particularly big game animals. 

engineering 

This section provides information for planning land uses 

related to urban development and to water management. 

Soils are rated for various uses, and the most limiting 

features are identified. The ratings are given in the following 

tables: Building site development, Sanitary facilities, 

Construction materials, and Water management. The 

ratings are based on observed performance of the soils and 

on the estimated data and test data in the "Soil properties" 

section. 

Information in this section is intended for land use 

planning, for evaluating land use alternatives, and for 

planning site investigations prior to design and 

construction. The information, however, has 

limitations. For example, estimates and other data 

generally apply only to that part of the soil within a depth of 

5 or 6 feet. Because of the map scale, small areas of 

different soils may be included within the mapped areas of a 

specific soil. 

The information is not site specific and does not eliminate 

the need for onsite investigation of the soils or for testing 

and analysis by personnel experienced in the design and 

construction of engineering works. 

Government ordinances and regulations that restrict 

certain land uses or impose specific design criteria were not 

considered in preparing the information in this section. Local 

ordinances and regulations need to be considered in 

planning, in site selection, and in design. 

Soil properties, site features, and observed performance 

were considered in determining the ratings 

in this section. During the fieldwork for this soil survey, 

determinations were made about grain-size 

distribution, liquid limit, plasticity index, soil reaction, depth 

to bedrock, hardness of bedrock within 5 to 6 feet of the 

surface, soil wetness, depth to a seasonal high water table, 

slope, likelihood of flooding, and natural soil structure 

aggregation. Data were collected about kinds of clay 

minerals, mineralogy of the sand and silt fractions, and the 

kind of adsorbed cations. Estimates were made for 

erodibility, permeability, corrosivity, shrink-swell 

potential, available water capacity, and other behavioral 

characteristics affecting engineering uses. 

This information can be used to (1) evaluate the potential 

of areas for residential, commercial, industrial, and recreation 

uses; (2) make preliminary estimates of construction 

conditions; (3) evaluate alternative routes for roads, streets, 

highways, pipelines, and underground cables; (4) 

evaluate alternative sites for sanitary landfills, septic tank 

absorption fields, and sewage lagoons; (5) plan detailed 

onsite investigations of soils and geology; (6) locate potential 

sources of gravel, sand, earthfill, and topsoil; (7) plan 

drainage systems, irrigation systems, ponds, terraces, 

and other structures for soil and water conservation; and (8) 

predict performance of proposed small structures and 

pavements by comparing the performance of existing similar 

structures on the same or similar soils. 

The information in the tables, along with the soil maps, 

the soil descriptions, and other data provided in this survey 

can be used to make additional interpretations. 

Some of the terms used in this soil survey have a 

special meaning in soil science and are defined in the 

Glossary. 

building site development 

Table 12 shows the degree and kind of soil limitations that 

affect shallow excavations, dwellings with and without 

basements, small commercial buildings, local roads and 

streets, and lawns and landscaping. The limitations are 

considered slight if soil properties and site features are 

generally favorable for the indicated use and limitations are 

minor and easily overcome; moderate if soil properties or site 

features are not favorable for the indicated use and special 

planning, design, or maintenance is needed to overcome or 

minimize the limitations; and severe if soil properties or site 

features are so unfavorable or so difficult to overcome that 

special design, significant increases in construction costs, 

and possibly increased maintenance are required. Special 

feasibility studies may be required where the soil limitations 

are severe. 

Shallow excavations are trenches or holes dug to a 

maximum depth of 5 or 6 feet for basements, graves, utility 

lines, open ditches, and other purposes. The ratings are 

based on soil properties, site features, and observed 

performance of the soils. The ease of digging, filling, and 

compacting is affected by the depth to 
bedrock, a cemented pan, or a very firm dense layer; stone 

content; soil texture; and slope. The time of the year that 

excavations can be made is affected by the depth to a 

seasonal high water table and the susceptibility of the soil to 

flooding. The resistance of the excavation walls or banks to 

sloughing or caving is affected by soil texture and the depth 

to the water table. 

Dwellings and small commercial buildings are structures 

built on shallow foundations on undisturbed soil. The load 

limit is the same as that for single-family dwellings no higher 

than three stories. Ratings are made for small commercial 

buildings without basements, for dwellings with basements, 

and for dwellings without basements. The ratings are based 

on soil properties, site features, and observed performance 

of the soils. A high water table, flooding, shrink-swell 

potential, and organic layers can cause the movement of 

footings. A high water table, depth to bedrock or to a 

cemented pan, large stones, and flooding affect the ease of 

excavation and construction. Landscaping and grading that 

require cuts and fills of more than 5 to 6 feet are not 

considered. 

Local roads and streets have an all-weather surface and 

carry automobile and light truck traffic all year. They have a 

subgrade of cut or fill soil material, a base of gravel, crushed 

rock, or stabilized soil material, and a flexible or rigid surface. 

Cuts and fills are generally limited to less than 6 feet. The 

ratings are based on soil properties, site features, and 

observed performance of the soils. Depth to bedrock or to a 

cemented pan, a high water table, flooding, large stones, 

and slope affect the ease of excavating and grading. Soil 

strength (as inferred from the engineering classification of the 

soil), shrink-swell potential, frost action potential, and depth 

to a high water table affect the traffic supporting capacity. 

Lawns and landscaping require soils on which turf and 

ornamental trees and shrubs can be established and 

maintained. The ratings are based on soil properties, site 

features, and observed performance of the soils. Soil 

reaction, a high water table, depth to bedrock or to a 

cemented pan, the available water capacity in the upper 40 

inches, and the content of salts, sodium, and suffidic 

materials affect plant growth. Flooding, wetness, slope, 

stoniness, and the amount of sand, clay, or organic matter in 

the surface layer affect trafficability after vegetation is 

established. 

Sanitary facilities 

Table 13 shows the degree and the kind of soil 

limitations that affect septic tank absorption fields, sewage 

lagoons, and sanitary landfills. The limitations are 

considered slight if soil properties and site features are 

generally favorable for the indicated use and limitations 

are minor and easily overcome; moderate if soil properties 

or site features are not favorable for the indicated use and 

special planning, design, or maintenance is needed to 

overcome or minimize the limitations; and severe if soil 

properties or site features 

are so unfavorable or so difficult to overcome that special 

design, significant increases in construction costs, and 

possibly increased maintenance are required. 

Table 13 also shows the suitability of the soils for use as 

daily cover for landfills. A rating of good indicates that soil 

properties and site features are favorable for the use and 

good performance and low maintenance can be expected; 

fair indicates that soil properties and site features are 

moderately favorable for the use and one or more soil 

properties or site features make the soil less desirable than 

the soils rated good; and poor indicates that one or more soil 

properties or site features are unfavorable for the use and 

overcoming the unfavorable properties requires special 

design, extra maintenance, or costly alteration. 

Septic tank absorption fields are areas in which effluent 

from a septic tank is distributed into the soil through 

subsurface tiles or perforated pipe. Only that part of the soil 

between depths of 24 and 72 inches is evaluated. The 

ratings are based on soil properties, site features, and 

observed performance of the soils. Permeability, a high 

water table, depth to bedrock or to a cemented pan, and 

flooding affect absorption of the effluent. Large stones and 

bedrock or a cemented pan interfere with installation. 

Unsatisfactory performance of septic tank absorption fields, 

including excessively slow absorption of effluent, surfacing of 

effluent, and hillside seepage, can affect public health. 

Ground water can be polluted if highly permeable sand and 

gravel or fractured bedrock is less than 4 feet below the base 

of the absorption field, if slope is excessive, or if the water 

table is near the surface. There must be unsaturated soil 

material beneath the absorption field to effectively filter the 

effluent. Many local ordinances require that this material be 

of a certain thickness. 

Sewage lagoons are shallow ponds constructed to hold 

sewage while aerobic bacteria decompose the solid and 

liquid wastes. Lagoons should have a nearly level floor 

surrounded by cut slopes or embankments of compacted 

soil. Lagoons generally are designed to hold the sewage 

within a depth of 2 to 5 feet. Nearly impervious soil material 

for the lagoon floor and sides is required to minimize 

seepage and contamination of ground water. 

Table 13 gives ratings for the natural soil that makes up 

the lagoon floor. The surface layer and, generally, 1 or 2 feet 

of soil material below the surface layer are excavated to 

provide material for the embankments. The ratings are based 

on soil properties, site features, and observed performance 

of the soils. Considered in the ratings are slope, permeability, 

a high water table, depth to bedrock or to a cemented pan, 

flooding, large stones, and content of organic matter. 

Excessive seepage due to rapid permeability of the soil or 

a water table that is high enough to raise the level of 

sewage in the lagoon causes a lagoon to function 
unsatisfactorily. Pollution results if seepage is 

excessive or if floodwater overtops the lagoon. A high 

content of organic matter is detrimental to proper 

functioning of the lagoon because it inhibits aerobic activity. 

Slope, bedrock, and cemented pans can cause construction 

problems, and large stones can hinder compaction of the 

lagoon floor. 

Sanitary landfills are areas where solid waste is disposed 

of by burying it in soil. There are two types of landfill-trench 

and area. In a trench landfill, the waste is placed in a 

trench. It is spread, compacted, and covered daily with a 

thin layer of soil excavated at the site. In an area landfill, the 

waste is placed in successive layers on the surface of the 

soil. The waste is spread, compacted, and covered daily 

with a thin layer of soil from a source away from the site. 

Both types of landfill must be able to bear heavy 

vehicular traffic. Both types involve a risk of ground 

water pollution. Ease of excavation and revegetation 

needs to be considered. 

The ratings in table 13 are based on soil properties, site 

features, and observed performance of the soils. 

Permeability, depth to bedrock or to a cemented pan, a high 

water table, slope, and flooding affect both types of landfill. 

Texture, stones and boulders, highly organic layers, soil 

reaction, and content of salts and sodium affect trench type 

landfills. Unless otherwise stated, the ratings apply only to 

that part of the soil within a depth of about 6 feet. For 

deeper trenches, a limitation rated slight or moderate may 

not be valid. Onsite investigation is needed. 

Daily cover for landfill is the soil material that is used to 

cover compacted solid waste in an area type sanitary 

landfill. The soil material is obtained offsite, transported to 

the landfill, and spread over the waste. 

Soil texture, wetness, coarse fragments, and slope affect 

the ease of removing and spreading the material during wet 

and dry periods. Loamy or silty soils that are free of large 

stones or excess gravel are the best cover for a landfill. 

Clayey soils are sticky or cloddy and are difficult to spread; 

sandy soils are subject to soil blowing. 

After soil material has been removed, the soil material 

remaining in the borrow area must be thick enough over 

bedrock, a cemented pan, or the water table to permit 

revegetation. The soil material used as final cover for a 

landfill should be suitable for plants. The surface layer 

generally has the best workability, more organic matter, and 

the best potential for plants. Material from the surface layer 

should be stockpiled for use as the final cover. 

construction materials 

Table 14 gives information about the soils as a source of 

roadfill, sand, gravel, and topsoil. The soils are rated good, 

fair, or poor as a source of roadfill and topsoil. They are 

rated as a probable or improbable source of sand and 

gravel. The ratings are based on soil 

properties and site features that affect the removal of the 

soil and its use as construction material. Normal 

compaction, minor processing, and other standard 

construction practices are assumed. Each soil is 

evaluated to a depth of 5 or 6 feet. 

Roadfill is soil material that is excavated in one place 

and used in road embankments in another place. In this 

table, the soils are rated as a source of roadfill for low 

embankments, generally less than 6 feet high and less 

exacting in design than higher embankments. 

The ratings are for the soil material below the surface 

layer to a depth of 5 or 6 feet. It is assumed that soil layers 

will be mixed during excavating and spreading. Many soils 

have layers of contrasting suitability within their profile. The 

table showing engineering index properties provides detailed 

information about each soil layer. This information can help 

determine the suitability of each layer for use as roadfill. The 

performance of soil after it is stabilized with lime or cement 

is not considered in the ratings. 

The ratings are based on soil properties, site features, 

and observed performance of the soils. The thickness of 

suitable material is a major consideration. The ease of 

excavation is affected by large stones, a high water table, 

and slope. How well the soil performs in place after it has 

been compacted and drained is determined by its strength 

(as inferred from the engineering classification of the soil) 

and shrink-swell potential. 

Soils rated good contain significant amounts of sand or 

gravel or both. They have at least 5 feet of suitable 

material, low shrink-swell potential, few cobbles and stones, 

and slopes of 15 percent or less. Depth to the water table is 

more than 3 feet. Soils rated fair are more than 35 percent 

silt- and clay-sized particles and have a plasticity index of 

less than 10. They have moderate shrink-swell potential, 

slopes of 15 to 25 percent, or many stones. Depth to the 

water table is 1 to 3 feet. Soils rated poor have a plasticity 

index of more than 10, a high shrink-swell potential, many 

stones, or slopes of more than 25 percent. They are wet, 

and the depth to the water table is less than 1 foot. They 

may have layers of suitable material, but the material is less 

than 3 feet thick. 

Sand and gravel are natural aggregates suitable for 

commercial use with a minimum of processing. Sand and 

gravel are used in many kinds of construction. Specifications 

for each use vary widely. In table 14, only the probability of 

finding material in suitable quantity is evaluated. The 

suitability of the material for specific purposes is not 

evaluated, nor are factors that affect excavation of the 

material. 

The properties used to evaluate the soil as a source of 

sand or gravel are gradation of grain sizes (as indicated by 

the engineering classification of the soil), the thickness of 

suitable material, and the content of rock fragments. Kinds 

of rock, acidity, and stratification are given in the soil series 

descriptions. Gradation of grain 
sizes is given in the table on engineering index 

properties. 

A soil rated as a probable source has a layer of clean 

sand or gravel or a layer of sand or gravel that is up to 12 

percent silty fines. This material must be at least 3 feet thick 

and less than 50 percent, by weight, large stones. All other 

soils are rated as an improbable source. Coarse fragments 

of soft bedrock, such as shale and siltstone, are not 

considered to be sand and gravel. 

Topsoil is used to cover an area so that vegetation can be 

established and maintained. The upper 40 inches of a soil is 

evaluated for use as topsoil. Also evaluated is the 

reclamation potential of the borrow area. 

Plant growth is affected by toxic material and by such 

properties as soil reaction, available water capacity, and 

fertility. The ease of excavating, loading, and spreading is 

affected by rock fragments, slope, a water table, soil texture, 

and thickness of suitable material. Reclamation of the 

borrow area is affected by slope, a water table, rock 

fragments, bedrock, and toxic material. 

Soils rated good have friable loamy material to a depth of 

at least 40 inches. They are free of stones and cobbles, 

have little or no gravel, and have slopes of less than 8 

percent. They are low in content of soluble salts, are 

naturally fertile or respond well to fertilizer, and are not so 

wet that excavation is difficult. 

Soils rated fair are sandy soils, loamy soils that have a 

relatively high content of clay, soils that have only 20 to 40 

inches of suitable material, soils that have an appreciable 

amount of gravel, stones, or soluble salts, or soils that have 

slopes of 8 to 15 percent. The soils are not so wet that 

excavation is difficult. 

Soils rated poor are very sandy or clayey, have less than 

20 inches of suitable material, have a large amount of 

gravel, stones, or soluble salts, have slopes of more than 15 

percent, or have a seasonal water table at or near the 

surface. 

The surface layer of most soils is generally preferred for 

topsoil because of its organic matter content. Organic matter 

greatly increases the absorption and retention of moisture 

and nutrients for plant growth. 

water management 

Table 15 gives information on the soil properties and site 

features that affect water management. The degree and 

kind of soil limitations are given for pond reservoir areas 

and embankments, dikes, and levees. The limitations 

are considered slight if soil properties and site features are 

generally favorable for the indicated use and limitations are 

minor and are easily overcome; moderate if soil properties 

or site features are not favorable for the indicated use and 

special planning, design, or maintenance is needed to 

overcome or minimize the limitations; and severe if soil 

properties or site features are so unfavorable or so difficult 

to overcome that special design, significant increase in 

construction costs, and possibly increased maintenance are 

required. 

This table also gives for each soil the restrictive 

features that affect drainage, irrigation, terraces and 

diversions, and grassed waterways. 

Pond reservoir areas hold water behind a dam or 

embankment. Soils best suited to this use have low 

seepage potential in the upper 60 inches. The seepage 

potential is determined by the permeability of the soil and 

the depth to fractured bedrock or other permeable material. 

Excessive slope can affect the storage capacity of the 

reservoir area. 

Embankments, dikes, and levees are raised structures of 

soil material, generally less than 20 feet high, constructed to 

impound water or to protect land against overflow. In this 

table, the soils are rated as a source of material for 

embankment fill. The ratings apply to the soil material below 

the surface layer to a depth of about 5 feet. It is assumed 

that soil layers will be uniformly mixed and compacted during 

construction. 

The ratings do not indicate the ability of the natural soil 

to support an embankment. Soil properties to a depth even 

greater than the height of the embankment can affect 

performance and safety of the embankment. Generally, 

deeper onsite investigation is needed to determine these 

properties. 

Soil material in embankments must be resistant to 

seepage, piping, and erosion and have favorable compaction 

characteristics. Unfavorable features include less than 5 feet 

of suitable material and a high content of stones or boulders, 

organic matter, or salts or sodium. A high water table affects 

the amount of usable material. It also affects trafficability. 

Drainage is the removal of excess surface and subsurface 

water from the soil. How easily and effectively the soil is 

drained depends on the depth to bedrock, to a cemented 

pan, or to other layers that affect the rate of water 

movement; permeability; depth to a high water table or 

depth of standing water if the soil is subject to ponding; 

slope; susceptibility to flooding; subsidence of organic layers; 

and potential frost action. Excavating and grading and the 

stability of ditchbanks are affected by depth to bedrock or to 

a cemented pan, large stones, slope, and the hazard of 

cutbanks caving. The productivity of the soil after drainage is 

adversely affected by extreme acidity or by toxic substances 

in the root zone, such as salts, sodium, or sulfur. Availability 

of drainage outlets is not considered in the ratings. 

Irrigation is the controlled application of water to 

supplement rainfall and support plant growth. The design 

and management of an irrigation system are affected by 

depth to the water table, the need for drainage, flooding, 

available water capacity, intake rate, permeability, erosion 

hazard, and slope. The construction of a system is affected 

by large stones and depth to bedrock or to a cemented pan. 

The performance of a system is affected 
by the depth of the root zone, the amount of salts or 

sodium, and soil reaction. 

Terraces and diversions are embankments or a 

combination of channels and ridges constructed across a 

slope to reduce erosion and conserve moisture by 

intercepting runoff. Slope, wetness, large stones, and depth 

to bedrock or to a cemented pan affect the construction of 

terraces and diversions. A restricted rooting depth, a severe 

hazard of wind or water erosion, an excessively coarse 

texture, and restricted permeability adversely affect 

maintenance. 

Grassed waterways are natural or constructed channels, 

generally broad and shallow, that conduct surface water to 

outlets at a nonerosive velocity. Large stones, wetness, 

slope, and depth to bedrock or to a cemented pan affect the 

construction of grassed waterways. A hazard of wind 

erosion, low available water capacity, restricted rooting 

depth, toxic substances such as salts or sodium, and 

restricted permeability adversely affect the growth and 

maintenance of the grass after construction. 
soil properties 

Data relating to soil properties are collected during the 

course of the soil survey. The data and the estimates of soil 

and water features, listed in tables, are explained on the 

following pages. 

Soil properties are determined by field examination of the 

soils and by laboratory index testing of some benchmark 

soils. Established standard procedures are followed. 

During the survey, many shallow borings are made and 

examined to identify and classify the soils and to delineate 

them on the soil maps. Samples are taken from some 

typical profiles and tested in the laboratory to determine 

grain-size distribution, plasticity, and compaction 

characteristics. 

Estimates of soil properties are based on field 

examinations, on laboratory tests of samples from the 

survey area, and on laboratory tests of samples of similar 

soils in nearby areas. Tests verify field observations, verify 

properties that cannot be estimated accurately by field 

observation, and help characterize key soils. 

The estimates of soil properties shown in the tables 

include the range of grain-size distribution and Atterberg 

limits, the engineering classifications, and the physical 

and chemical properties of the major layers of each soil. 

Pertinent soil and water features also are given. 

engineering index properties 

Table 16 gives estimates of the engineering classification 

and of the range of index properties for the major layers of 

each soil in the survey area. Most soils have layers of 

contrasting properties within the upper 5 or 6 feet. 

Depth to the upper and lower boundaries of each layer is 

indicated. The range in depth and information on other 

properties of each layer are given for each soil series under 

"Soil series and their morphology." 

Texture is given in the standard terms used by the U.S. 

Department of Agriculture. These terms are defined 

according to percentages of sand, silt, and clay in the 

fraction of the soil that is less than 2 millimeters in diameter. 

"Loam," for example, is soil that is 7 to 27 percent clay, 28 

to 50 percent silt, and less than 52 percent sand. If a soil 

contains particles coarser than sand, an appropriate 

modifier is added, for example, "gravelly." Textural 

terms are defined in the Glossary. 

Classification of the soils is determined according to the 

Unified soil classification system (2) and the system 

adopted by the American Association of State Highway and 

Transportation Officials (1). 

The Unified system classifies soils according to properties 

that affect their use as construction material. Soils are 

classified according to grain-size distribution of the fraction 

less than 3 inches in diameter and according to plasticity 

index, liquid limit, and organic matter content. Sandy and 

gravelly soils are identified as GW, GP, GM, GC, SW, SF, 

SM, and SC; silty and clayey soils as ML, CL, OL, MH, CH, 

and OH; and highly organic soils as Pt. Soils exhibiting 

engineering properties of two groups can have a dual 

classification, for example, SP-SM. 

The AASHTO system classifies soils according to those 

properties that affect roadway construction and 

maintenance. In this system, the fraction of a mineral soil 

that is less than 3 inches in diameter is classified in one of 

seven groups from A-1 through A-7 on the basis of grainsize distribution, liquid limit, and plasticity index. Soils in 

group A-1 are coarse grained and low in content of fines (silt 

and clay). At the other extreme, soils in group A-7 are fine 

grained. Highly organic soils are classified in group A-8 on 

the basis of visual inspection. 

Rock fragments larger than 3 inches in diameter are 

indicated as a percentage of the total soil on a dry-weight 

basis. The percentages are estimates determined mainly by 

converting volume percentage in the field to weight 

percentage. 

Percentage (of soil particles) passing designated sieves is 

the percentage of the soil fraction less than 3 inches in 

diameter based on an oven-dry weight. The sieves, 

numbers 4, 10, 40, and 200 (USA Standard Series), have 

openings of 4.76, 2.00, 0.420, and 0.074 millimeters, 

respectively. Estimates are based on laboratory tests of soils 

sampled in the survey area and in nearby areas and on 

estimates made in the field. 

Liquid limit and plasticity index (Atterberg limits) indicate the 

plasticity characteristics of a soil. The estimates are based 

on test data from the survey area or from nearby areas and 

on field examination. 

The estimates of grain-size distribution, liquid limit, and 

plasticity index are rounded to the nearest 5 percent. Thus, if 

the ranges of gradation and Atterberg limits extend a 

marginal amount (1 or 2 percentage points) across 

classification boundaries, the classification in the marginal 

zone is omitted in the table. 
physical and chemical properties 

Table 17 shows estimates of some characteristics and 

features that affect soil behavior. These estimates are given 

for the major layers of each soil in the survey area. The 

estimates are based on field observations and on test data 

for these and similar soils. 

Clay as a soil separate consists of mineral soil particles 

that are less than 0.002 millimeter in diameter. In this table, 

the estimated clay content of each major soil layer is given 

as a percentage, by weight, of the soil material that is less 

than 2 millimeters in diameter. 

The amount and kind of clay greatly affect the fertility and 

physical condition of the soil. They determine the ability of 

the soil to adsorb cations and to retain moisture. They 

influence shrink-swell potential, permeability, and 

plasticity, the ease of soil dispersion, and other soil 

properties. The amount and kind of clay in a soil also affect 

tillage and earth-moving operations. 

Permeability refers to the ability of a soil to transmit 

water or air. The estimates indicate the rate of downward 

movement of water when the soil is saturated. They are 

based on soil characteristics observed in the field, 

particularly structure, porosity, and texture. Permeability is 

considered in the design of soil drainage systems, septic 

tank absorption fields, and construction where the rate of 

water movement under saturated conditions affects behavior.

Available water capacity refers to the quantity of water that 

the soil is capable of storing for use by plants. The capacity 

for water storage is given in inches of water per inch of soil 

for each major soil layer. The capacity varies, depending on 

soil properties that affect the retention of water and the depth 

of the root zone. The most important properties are the 

content of organic matter, soil texture, bulk density, and soil 

structure. Available water capacity is an important factor in 

the choice of plants or crops to be grown and in the design 

and management of irrigation systems. Available water 

capacity is not an estimate of the quantity of water actually 

available to plants at any given time. 

Soil reaction is a measure of acidity or alkalinity and is 

expressed as a range in pH values. The range in pH of each 

major horizon is based on many field tests. For many soils, 

values have been verified by laboratory analyses. Soil 

reaction is important in selecting crops and other plants, in 

evaluating soil amendments for fertility and stabilization, and 

in determining the risk of corrosion. 

Salinity is a measure of soluble salts in the soil at 

saturation. It is expressed as the electrical conductivity of 

the saturation extract, in millimhos per centimeter at 25 

degrees C. Estimates are based on field and laboratory 

measurements at representative sites of nonirrigated 

soils. The salinity of irrigated soils is affected by the quality 

of the irrigation water and by the frequency of water 

application. Hence, the salinity of 

soils in individual fields can differ greatly from the value 

given in the table. Salinity affects the suitability of a soil for 

crop production, the stability of soil if used as construction 

material, and the potential of the soil to corrode metal and 

concrete. 

Shrink-swell potential is the potential for volume change in 

a soil with a loss or gain in moisture. Volume change occurs 

mainly because of the interaction of clay minerals with water 

and varies with the amount and type of clay minerals in the 

soil. The size of the load on the soil and the magnitude of 

the change in soil moisture content influence the amount of 

swelling of soils in place. Swelling was estimated on the 

basis of the kind and amount of clay minerals in the soil and 

on measurements of similar soils. 

If the shrink-swell potential is rated moderate to very 

high, shrinking and swelling can cause damage to buildings, 

roads, and other structures. Special design is often needed. 

Shrink-swell potential classes are based on the change in 

length of an unconfined clod as moisture content is 

increased from air-dry to field capacity. The change is based 

on the soil fraction less than 2 millimeters in diameter. The 

classes are low, a change of less than 3 percent; moderate, 

3 to 6 percent; and high, more than 6 percent. 

Erosion factor K indicates the susceptibility of a soil to 

sheet and rill erosion by water. Factor K is one of six factors 

used in the Universal Soil Loss Equation (USLE) to predict 

the average annual rate of soil loss by sheet and rill erosion 

in tons per acre per year. The estimates are based primarily 

on percentage of silt, sand, and organic matter (up to 4 

percent) and on soil structure and permeability. Rock 

fragments in the soil reduce the K value; therefore, the K 

values expresed in table 17 reflect the amount of rock 

fragments in the soil. Values of K range from 0.05 to 0.69. 

The higher the value the more susceptible the soil is to 

sheet and rill erosion by water. 

Erosion factor T is an estimate of the maximum average 

annual rate of soil erosion by wind or water that can occur 

without affecting crop productivity over a sustained period. 

The rate is in tons per acre per year. 

Wind erodibility groups are made up of soils that have 

similar properties affecting their resistance to wind erosion 

in cultivated areas. The groups indicate the susceptibility of 

soil to wind erosion and the amount of soil lost. Depending 

on the total content of rock fragments in the surface layer, 

soils containing rock fragments can be assigned to any of 

the wind erodibility groups. Soils are grouped according to 

the following distinctions: 

1. Sands, coarse sands, fine sands, and very fine sands. 

These soils are generally not suitable for crops. They are 

extremely erodible, and vegetation is difficult to establish. 
2. Loamy sands, loamy fine sands, and loamy very fine 

sands. These soils are very highly erodible. Crops can be 

grown if intensive measures to control wind erosion are 

used. 

3. Sandy loams, coarse sandy loams, fine sandy loams, 

and very fine sandy loams. These soils are highly erodible. 

Crops can be grown if intensive measures to control wind 

erosion are used. 

4L. Calcareous loamy soils that are less than 35 percent 

clay and more than 5 percent finely divided calcium 

carbonate. These soils are erodible. Crops can be grown if 

intensive measures to control wind erosion are used. 

4. Clays, silty clays, clay loams, and silty clay loams that 

are more than 35 percent clay. These soils are moderately 

erodible. Crops can be grown if measures to control wind 

erosion are used. 

5. Loamy soils that are less than 18 percent clay and less 

than 5 percent finely divided calcium carbonate and sandy 

clay loams and sandy clays that are less than 5 percent 

finely divided calcium carbonate. These soils are slightly 

erodible. Crops can be grown if measures to control wind 

erosion are used. 

6. Loamy soils that are 18 to 35 percent clay and less 

than 5 percent finely divided calcium carbonate, except 

silty clay loams. These soils are very slightly erodible. 

Crops can easily be grown. 

7. Silty clay loams that are less than 35 percent clay and 

less than 5 percent finely divided calcium carbonate. These 

soils are very slightly erodible. Crops can easily be grown. 

8. Stony or gravelly soils and other soils not subject to 

wind erosion. 

Organic matter is the plant and animal residue in the soil 

at various stages of decomposition. 

In table 17, the estimated content of organic matter of the 

plow layer is expressed as a percentage, by weight, of the 

soil material that is less than 2 millimeters in diameter. 

The content of organic matter of a soil can be 

maintained or increased by returning crop residue to the soil. 

Organic matter affects the available water capacity, 

infiltration rate, and tilth. It is a source of nitrogen and other 

nutrients for crops. 

soil and water features 

Tables 18 and 19 give estimates of various soil and 

water features. The estimates are used in land use 

planning that involves engineering considerations. 

Hydrologic soil groups are used to estimate runoff from 

precipitation. Soils not protected by vegetation are 

assigned to one of four groups. They are grouped 

according to the intake of water when the soils are 

thoroughly wet and receive precipitation from long-duration 

storms. 

The four hydrologic soil groups are: 

Group A. Soils having a high infiltration rate (low runoff 

potential) when thoroughly wet. These consist mainly of 

deep, well drained to excessively drained sands or gravelly 

sands. These soils have a high rate of water transmission. 

Group B. Soils having a moderate infiltration rate when 

thoroughly wet. These consist chiefly of moderately deep or 

deep, moderately well drained or well drained soils that have 

moderately fine texture to moderately coarse texture. These 

soils have a moderate rate of water transmission. 

Group C. Soils having a slow infiltration rate when 

thoroughly wet. These consist chiefly of soils having a layer 

that impedes the downward movement of water or soils of 

moderately fine texture or fine texture. These soils have a 

slow rate of water transmission. 

Group D. Soils having a very slow infiltration rate (high 

runoff potential) when thoroughly wet. These consist chiefly of 

clays that have a high shrink-swell potential, soils that have a 

permanent high water table, soils that have a claypan or clay 

layer at or near the surface, and soils that are shallow over 

nearly impervious material. These soils have a very slow rate 

of water transmission. 

Flooding, the temporary inundation of an area, is caused 

by overflowing streams, by runoff from adjacent slopes, or by 

tides. Water standing for short periods after rainfall or 

snowmelt and water in swamps and marshes are not 

considered flooding. 

Table 18 gives the frequency and duration of flooding 

and the time of year when flooding is most likely. 

Frequency, duration, and probable dates of occurrence are 

estimated. Frequency is expressed as none, rare, common, 

occasional, and frequent. None means that flooding is not 

probable; rare that it is unlikely but possible under unusual 

weather conditions; common that it is likely under normal 

conditions; occasional that it occurs on an average of once 

or less in 2 years; and frequent that it occurs on an average 

of more than once in 2 years. Duration is expressed as very 

brief if less than 2 days, brief if 2 to 7 days, and long if more 

than 7 days. Probable dates are expressed in months; 

November-May, for example, means that flooding can occur 

during the period November through May. 

The information is based on evidence in the soil profile, 

namely thin strata of gravel, sand, silt, or clay deposited by 

floodwater; irregular decrease in organic matter content with 

increasing depth; and absence of distinctive horizons that 

form in soils that are not subject to flooding. 

Also considered are local information about the extent and 

levels of flooding and the relation of each soil on the 

landscape to historic floods. Information on the extent of 

flooding based on soil data is less specific than that provided 

by detailed engineering surveys that delineate flood-prone 

areas at specific flood frequency levels. 
High water table (seasonal) is the highest level of a 

saturated zone in the soil in most years. The depth to a 

seasonal high water table applies to undrained soils. The 

estimates are based mainly on the evidence of a saturated 

zone, namely grayish colors or mottles in the soil. Indicated in 

table 18 are the depth to the seasonal high water table; the 

kind of water table-that is, perched, artesian, or apparent; 

and the months of the year that the water table commonly is 

high. A water table that is seasonally high for less than 1 

month is not indicated in table 18. 

An apparent water table is a thick zone of free water in 

the soil. It is indicated by the level at which water stands in 

an uncased borehole after adequate time is allowed for 

adjustment in the surrounding soil. An artesian water table is 

under hydrostatic head, generally beneath an impermeable 

layer. When this layer is penetrated, the water level rises in 

an uncased borehole. A perched water table is water 

standing above an unsaturated zone. In places an upper, 

or perched, water table is separated from a lower one by a 

dry zone. 

Only saturated zones within a depth of about 6 feet are 

indicated. A plus sign preceding the range in depth indicates 

that the water table is above the surface of the soil. The first 

numeral in the range indicates how high the water rises above 

the surface. The second numeral indicates the depth below 

the surface. 

Depth to bedrock is given in table 19 if bedrock is within a 

depth of 5 feet. The depth is based on many soil borings 

and on observations during soil mapping. The rock is 

specified as either soft or hard. If the rock is soft or fractured, 

excavations can be made with trenching machines, 

backhoes, or small rippers. If the rock is hard or massive, 

blasting or special equipment generally is needed for 

excavation. 

Cemented pans are cemented or indurated subsurface 

layers within a depth of 5 feet. Such pans cause difficulty in 

excavation. Pans are classified as thin or thick. A thin pan is 

less than 3 inches thick if continuously indurated or less than 

18 inches thick if discontinuous or fractured. Excavations 

can be made by trenching machines, 

backhoes, or small rippers. A thick pan is more than 3 inches 

thick if continuously indurated or more than 18 inches thick if 

discontinuous or fractured. Such a pan is so thick or 

massive that blasting or special equipment is needed in 

excavation. 

Potential frost action is the likelihood of upward or lateral 

expansion of the soil caused by the formation of segregated 

ice lenses (frost heave) and the subsequent collapse of the 

soil and loss of strength on thawing. Frost action occurs 

when moisture moves into the freezing zone of the soil. 

Temperature, texture, density, permeability, content of 

organic matter, and depth to the water table are the most 

important factors considered in evaluating the potential for 

frost action. It is assumed that the soil is not insulated by 

vegetation or snow and is not artificially drained. Silty 

and highly structured clayey soils that have a high water 

table in winter are most susceptible to frost action. Well 

drained, very gravelly, or very sandy soils are the least 

susceptible. Frost heave and low soil strength during thawing 

cause damage mainly to pavements and other rigid 

structures. 

Risk of corrosion pertains to potential soil-induced 

electrochemical or chemical action that dissolves or weakens 

uncoated steel or concrete. The rate of corrosion of 

uncoated steel is related to such factors as soil moisture, 

particle-size distribution, acidity, and electrical 

conductivity of the soil. The rate of corrosion of concrete is 

based mainly on the sulfate and sodium content, texture, 

moisture content, and acidity of the soil. Special site 

examination and design may be needed if the combination of 

factors creates a severe corrosion environment. The steel in 

installations that intersect soil boundaries or soil layers is 

more susceptible to corrosion than steel in installations that 

are entirely within one kind of soil or within one soil layer. 

For uncoated steel, the risk of corrosion, expressed as 

low, moderate, or high, is based on soil drainage class, total 

acidity, electrical resistivity near field capacity, and electrical 

conductivity of the saturation extract. 

For concrete, the risk of corrosion is also expressed as 

low, moderate, or high. It is based on soil texture, acidity, 

and amount of sulfates in the saturation extract. 
classification of the soils

The system of soil classification used by the National 

Cooperative Soil Survey has six categories (23). Beginning 

with the broadest, these categories are the order, 

suborder, great group, subgroup, family, and series. 

Classification is based on soil properties observed in 

the field or inferred from those observations or from 

laboratory measurements. In table 20, the soils of the survey 

area are classified according to the system. The categories 

are defined in the following paragraphs. 

ORDER. Five soil orders are recognized in this 

survey area. The differences among orders reflect the 

dominant soil-forming processes and the degree of soil 

formation. Each order is identified by a word ending in sol. 

An example is Mollisol. 

SUBORDER. Each order is divided into suborders 

primarily on the basis of properties that influence soil 

genesis and are important to plant growth or properties that 

reflect the most important variables within the orders. The 

last syllable in the name of a suborder indicates the order. 

An example is Aquoll (Aqu, meaning water, plus oll, from 

Mollisol). 

GREAT GROUP. Each suborder is divided into great 

groups on the basis of close similarities in kind, arrangement, 

and degree of development of pedogenic horizons; soil 

moisture and temperature regimes; and base status. 

Each great group is identified by the name of a suborder and 

by a prefix that indicates a property of the soil. An example 

is Haplaquolls (Hapl, meaning minimal horizonation, plus 

aquoll, the suborder of the Mollisols that have an aquic 

moisture regime). 

SUBGROUP. Each great group has a typic subgroup. 

Other subgroups are intergrades or extragrades. The typic 

is the central concept of the great group; it is not 

necessarily the most extensive. Intergrades are 

transitions to other orders, suborders, or great 

groups. Extragrades have some properties that are 

not representative of the great group but do not indicate 

transitions to any other known kind of soil. Each subgroup 

is identified by one or more adjectives preceding the 

name of the great group. The adjective Cumulic identifies 

the subgroup that has a mollic epipedon that is thicker 

than that of the Typic great group. An example is Cumulic 

Haplaquolls. 

FAMILY. Families are established within a subgroup 

on the basis of physical and chemical properties and other 

characteristics that affect management. Mostly the 

properties are those of horizons below plow depth where 

there is much biological activity. Among the properties and 

characteristics considered are particle-size class, mineral 

content, temperature regime, depth of the root zone, 

consistence, moisture equivalent, slope, and permanent 

cracks. A family name consists of the name of a subgroup 

preceded by terms that indicate soil properties. An 

example is fine-loamy, mixed, mesic Cumulic Haplaquolls.

SERIES. The series consists of soils that have similar 

horizons in their profile. The horizons are similar in color, 

texture, structure, reaction, consistence, mineral and chemical 

composition, and arrangement in the profile. The texture of 

the surface layer or of the substratum can differ within a 

series. 

soil series and their morphology 

In this section, each soil series recognized in the survey 

area is described. The descriptions are arranged in 

alphabetic order. 

Characteristics of the soil and the material in which it 

formed are identified for each series. The soil is compared 

with similar soils and with nearby soils of other series. A 

pedon, a small three-dimensional area of soil, that is typical 

of the series in the survey area is described. The detailed 

description of each soil horizon follows standards in the Soil 

Survey Manual (21). Many of the technical terms used in the 

descriptions are defined in Soil Taxonomy (23). Unless 

otherwise stated, colors in the descriptions are for dry soil. 

Following the pedon description is the range of important 

characteristics of the soils in the series. 

The map units of each soil series are described in the 

section "Detailed soil map units." 

Ashue series 

The Ashue series consists of very deep, well drained 

soils on low terraces in stream valleys. These soils 

formed in alluvium. Slopes range from 0 to 2 percent. 

Elevation is 700 to 1,700 feet. The average annual 

precipitation is 7 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 
Typical pedon of Ashue loam, about 3 miles southeast of 

Naches, about 450 feet east and 420 feet south of the 

northwest corner of sec. 23, T. 14 N., R. 17 E. 

Ap-0 to 10 inches; brown (10YR 5/3) loam, dark brown 

(10YR 3/3) moist; moderate fine granular structure; 

slightly hard, friable, slightly sticky and slightly plastic; 

many very fine roots; many fine tubular pores; 5 percent 

pebbles; mildly alkaline; gradual wavy boundary. 

B21t-10 to 15 inches; yellowish brown (10YR 5/4) very 

gravelly heavy loam, dark brown (10YR 3/3) moist; 

moderate medium subangular blocky structure; hard, 

friable, sticky and plastic; many fine roots; common fine 

tubular pores; common thin clay films on faces of peds; 

45 percent pebbles; mildly alkaline; clear wavy 

boundary. 

B22t-15 to 29 inches; yellowish brown (10YR 5/4) very 

gravelly sandy clay loam, dark brown (10YR 3/3) moist; 

weak fine subangular blocky structure; slightly hard, very 

friable, sticky and plastic; common fine roots; common 

fine pores; common thin clay films on faces of peds; 40 

percent pebbles and 10 percent cobbles; mildly 

alkaline; abrupt wavy boundary. 

C1-29 to 34 inches; dark yellowish brown (10YR 4/4) very 

gravelly sandy loam, dark brown (10YR 3/3) moist; 

massive; soft, friable, nonsticky and nonplastic; few 

fine roots; 45 percent pebbles and 15 percent cobbles; 

mildly alkaline; abrupt wavy boundary. 

IIC2-34 to 60 inches; dark grayish brown (10YR 4/2) 

extremely gravelly sand, very dark grayish brown (10YR 

3/2) moist; single grain; loose; few fine roots; 60 percent 

pebbles and 15 percent cobbles; mildly alkaline. 

The mollic epipedon is 7 to 12 inches thick. The profile is 

neutral or mildly alkaline. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when dry or moist. 

The B2t horizon has hue of 10YR or 7.5YR, value of 4 or 5 

when dry and 3 or 4 when moist, and chroma of 3 or 4 when 

dry or moist. It is very gravelly loam or very gravelly sandy 

clay loam. 

The C and IIC horizons have hue of 10YR or 7.5YR, 

value of 4 or 5 when dry and 3 or 4 when moist, and 

chroma of 2 to 4 when dry or moist. The C horizon is 

very gravelly sandy loam or very gravelly loam. The IIC 

horizon is extremely gravelly sand or extremely cobbly 

sand. 

Bakeoven series 

The Bakeoven series consists of very shallow, well 

drained soils on uplands. These soils formed in loess 

and in residuum derived from basalt. Slopes range from 0 

to 45 percent. Elevation is 1,500 to 3,200 feet. The average 

annual precipitation is 10 to 12 inches, the average annual 

air temperature is about 50 degrees F, and the average 

frost-free season is 135 to 150 days. 

Typical pedon of Bakeoven very cobbly silt loam, 0 to 30 

percent slopes, about 10 miles north of Sunnyside, about 

1,600 feet north and 300 feet east of the southwest corner 

of sec. 6, T. 11 N., R. 23 E. 

A1-0 to 4 inches; brown (10YR 5/3) very cobbly silt loam, 

dark brown (10YR 3/3) moist; moderate fine granular 

structure; slightly hard, friable, slightly sticky and slightly 

plastic; many very fine roots; few fine tubular pores; 15 

percent pebbles and 35 percent cobbles; neutral; abrupt 

wavy boundary. 

B21-4 to 7 inches; dark yellowish brown (10YR 4/4) 

gravelly clay loam, dark brown (10YR 31/3) moist; 

moderate medium angular blocky structure; hard, firm, 

sticky and plastic; common very fine roots; few fine 

tubular pores; 20 percent pebbles and 5 percent 

cobbles; neutral; abrupt wavy boundary. 

B22-7 to 10 inches; dark yellowish brown (10YR 4/4) 

very gravelly clay loam, dark brown (10YR 3/3) moist; 

moderate fine angular blocky structure; hard, firm, 

sticky and plastic; few very fine roots; few fine tubular 

pores; 40 percent pebbles and 15 percent cobbles; 

neutral; abrupt wavy boundary. 

IIR-10 inches; basalt. 

Depth to basalt ranges from 4 to 12 inches. The solum 

has but of 10YR or 7.5YR. The A horizon has chroma of 2 

or 3 when dry or moist. The B2 horizon averages more than 

35 percent coarse fragments. It is gravelly clay loam, very 

gravelly clay loam, very gravelly loam, or very cobbly loam. 

Bickleton series 

The Bickleton series consists of deep, well drained soils 

on uplands. These soils formed in loess and in residuum 

derived from basalt. Slopes range from 0 to 30 percent. 

Elevation is 2,600 to 3,200 feet. The average annual 

precipitation is 11 to 14 inches, the average annual air 

temperature is about 47 degrees F, and the average frostfree season is 120 to 160 days. 

Typical pedon of Bickleton silt loam, 0 to 5 percent 

slopes, about 17 miles southwest of Mabton, about 

2,300 feet west and 1,100 feet north of the southeast 

corner of sec. 35, T. 7 N., R. 20 E. 

Ap-0 to 5 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; moderate fine 

granular structure; slightly hard, friable, slightly sticky 

and slightly plastic; many very fine roots; neutral; abrupt 

smooth boundary. 
A12-5 to 10 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; weak fine 

angular blocky structure; slightly hard, friable, 

slightly sticky and slightly plastic; common very fine 

roots; common very fine pores; neutral; abrupt smooth 

boundary. 

B21-10 to 19 inches; brown (10YR 4/3) heavy silt loam, 

dark brown (10YR 3/3) moist; moderate coarse 

prismatic structure; slightly hard, firm, slightly sticky and 

slightly plastic; common very fine roots; common very 

fine pores; mildly alkaline; abrupt smooth boundary. 

B22-19 to 26 inches; brown (10YR 5/3) heavy silt loam, 

dark brown (10YR 3/3) moist; moderate coarse 

prismatic structure parting to moderate medium 

prismatic; slightly hard, firm, slightly sticky and 

slightly plastic; common very fine roots; common very 

fine pores; mildly alkaline; abrupt smooth boundary. 

C1-26 to 35 inches; pale brown (10YR 6/3) heavy silt 

loam, dark brown (10YR 3/3) moist; massive; slightly 

hard, friable, slightly sticky and slightly plastic; common 

very fine roots; common very fine pores; 10 percent 

gravel; slightly effervescent; mildly alkaline; abrupt 

smooth boundary. 

IIC2ca-35 to 42 inches; brown (10YR 5/3) extremely 

gravelly silty clay loam, dark brown (10YR 4/3) moist; 

massive; hard, friable, sticky and plastic; few very fine 

roots; few very fine pores; 60 percent pebbles and 10 

percent cobbles; violently effervescent; moderately 

alkaline; abrupt smooth boundary. 

IIR-42 inches; basalt. 

Depth to basalt ranges from 40 to 60 inches. The 10- to 

40-inch control section is 18 to 25 percent clay. The mollic 

epipedon is 10 to 16 inches thick. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when moist or dry. It 

is neutral or mildly alkaline. 

The B2 horizon has value of 4 to 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when moist or dry. 

It is neutral or mildly alkaline. 

The C horizon is heavy silt loam or silty clay loam. 

The IIC horizon is very gravelly silt loam or extremely 

gravelly silty clay loam. It is mildly alkaline or moderately 

alkaline. 

Bocker series 

The Bocker series consists of very shallow, well drained 

soils on mountaintops and broad ridgetops. These soils 

formed in residuum derived from basalt and containing 

minor amounts of loess. Slopes range from 0 to 25 

percent. Elevation is 2,800 to 5,500 feet. The average 

annual precipitation is 18 to 40 inches, the 

average annual air temperature is about 42 degrees F, 

and the average frost-free season is 85 to 130 days. 

Typical pedon of Bocker very cobbly loam, 0 to 25 

percent slopes, about 12 miles west of Cowiche, about 600 

feet south and 400 feet east of the northwest corner of sec. 

4, T. 13 N., R. 15 E. 

A1-0 to 3 inches; dark grayish brown (10YR 4/2) very 

cobbly loam, very dark grayish brown (10YR 3/2) moist; 

moderate medium granular structure; soft, very friable, 

slightly sticky and slightly plastic; common very fine and 

few fine roots; 30 percent pebbles and 20 percent 

cobbles; slightly acid; abrupt smooth boundary. 

B2-3 to 7 inches; dark brown (10YR 4/3) very cobbly 

loam, very dark grayish brown (10YR 3/2) moist; weak 

very fine subangular blocky structure; slightly hard, very 

friable, slightly sticky and slightly plastic; few very fine 

roots; few very fine irregular pores; 15 percent pebbles 

and 25 percent cobbles; slightly acid; abrupt wavy 

boundary. 

R-7 inches; fractured basalt. 

From 10 to 20 percent of the surface is covered with 

cobbles. The mollic epipedon is 5 to 10 inches thick. 

Depth to fractured basalt ranges from 5 to 10 inches. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 3 or 4 when dry. 

The B horizon has value of 4 or 5 when dry and 3 or 4 

when moist, and it has chroma of 3 or 4 when dry and 2 or 3 

when moist. It is very cobbly loam or very cobbly silt loam. 

Burke series 

The Burke series consists of moderately deep, well 

drained soils on uplands. These soils formed in loess 

overlying a lime- and silica- cemented duripan. Slopes range 

from 2 to 40 percent. Elevation is 1,000 to 1,300 feet. The 

average annual precipitation is 6 to 9 inches, the average 

annual air temperature is about 50 degrees F, and the 

average frost-free season is 135 to 180 days. 

Typical pedon of Burke silt loam, 2 to 5 percent slopes, 

about 5 miles north of Outlook, about 700 feet north and 

50 feet east of the southwest corner of sec. 30, T. 11 N., 

R. 22 E. 

Ap-0 to 7 inches; pale brown (10YR 6/3) silt loam, dark 

brown (10YR 4/3) moist; weak fine granular structure; 

slightly hard, friable, slightly sticky and slightly plastic; 

many fine roots; mildly alkaline; abrupt smooth boundary.

AC-7 to 16 inches; pale brown (10YR 6/3) silt loam, 

dark brown (10YR 4/3) moist; weak coarse 

prismatic structure; slightly hard, friable, slightly 

sticky and slightly plastic; few very fine roots; 

common fine pores; mildly alkaline; abrupt wavy 

boundary. 
C1-16 to 24 inches; pale brown (10YR 6/3) silt loam, dark 

brown (10YR 4/3) moist; massive; slightly hard, friable, 

slightly sticky and slightly plastic; few very fine roots; 

common fine pores; moderately alkaline; abrupt smooth 

boundary. 

C2ca-24 to 25 inches; pale brown (10YR 6/3) silt loam, 

dark brown (10YR 4/3) moist; massive; slightly hard, 

friable, slightly sticky and slightly plastic; few very fine 

roots; common fine pores; secondary lime in root 

channels; strongly effervescent; moderately alkaline; 

abrupt smooth boundary. 

C3casim-25 inches; indurated lime- and silica-cemented 

duripan. 

Depth to the duripan ranges from 20 to 40 inches. The 

duripan is underlain by basalt at a depth of 30 inches or 

more. The profile has value of 4 or 5 when moist and 6 or 7 

when dry, and it has chroma of 2 or 3 when dry or moist. 

The A horizon is silt loam or very stony silt loam. The AC 

and C horizons are silt loam or very fine sandy loam. They 

are mildly alkaline to strongly alkaline. 

Carmack series 

The Carmack series consists of very deep, well drained 

soils on uplands and north-facing mountainsides. These 

soils formed in residuum derived dominantly from 

conglomerate and tuffaceous sandstone. Slopes range from 0 

to 75 percent. Elevation is 2,200 to 3,500 feet. The average 

annual precipitation is 20 to 35 inches, the average annual 

air temperature is about 43 degrees F, and the average 

length of the growing season, at 28 degrees F, is 145 to 170 

days. 

Typical pedon of Carmack loam, 0 to 25 percent slopes, 

about 3 miles southwest of Nile, about 1,000 feet north and 

400 feet west of the southeast corner of sec. 16, T. 15 N., R. 

15 E. 

O1-2 inches to 0; decomposing forest litter. 

A11-0 to 1 inch; grayish brown (10YR 5/2) and light gray 

(10YR 7/2) loamy sand, very dark grayish brown (10YR 

3/2) and light brownish gray (10YR 6/2) moist; single 

grain; loose; few very fine and fine roots; medium 

acid; abrupt smooth boundary. 

A12-1 inch to 15 inches; brown (10YR 5/3) loam, dark 

brown (10YR 3/3) moist; moderate fine granular 

structure; soft, very friable, slightly sticky and 

slightly plastic; few very fine and fine roots; few very 

fine irregular pores; 5 percent pebbles; slightly acid; 

abrupt smooth boundary. 

B1-15 to 21 inches; brown (10YR 5/3) loam, dark 

yellowish brown (10YR 3/4) moist; moderate very 

fine subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; few very fine 

and fine roots; common very fine irregular pores; 

medium acid; clear wavy boundary. 

B2t-21 to 43 inches; pale brown (10YR 6/3) silty clay 

loam, dark yellowish brown (10YR 3/4) moist; moderate 

fine subangular blocky structure; slightly hard, friable, 

sticky and plastic; few very fine and fine roots and 

common medium roots; common very fine irregular 

pores; common thin clay films on faces of peds; 

medium acid; clear wavy boundary. 

B3-43 to 60 inches; pale brown (10YR 6/3) loam, dark 

yellowish brown (10YR 3/4) moist; moderate very fine 

subangular blocky structure; soft, friable, slightly sticky 

and slightly plastic; few fine and common medium 

roots; few very fine irregular pores; medium acid. 

Thickness of the mollic epipedon is 10 to 15 inches. The 

control section is 0 to 10 percent pebbles and cobbles. 

Base saturation ranges from 55 to 65 percent. 

The A11 horizon is discontinuous in some pedons. The 

A12 horizon has hue of 7.5YR or 10YR, and it has chroma 

of 2 or 3 when dry or moist. It is loam or cobbly loam. 

The B1 horizon has hue of 7.5YR or 10YR, value of 5 to 7 

when dry and 3 to 5 when moist, and chroma of 2 or 3 

when dry and 2 to 4 when moist. It is loam, silt loam, or 

gravelly loam. The B2t horizon has value of 6 or 7 when dry 

and 3 or 4 when moist, and it has chroma of 2 or 3 when dry 

and 2 to 4 when moist. It is silty clay loam, clay loam, or 

loam. The B3 horizon is loam or silt loam. 

Cleman series 

The Cleman series consists of very deep, well drained 

soils on flood plains and alluvial fans. These soils formed in 

alluvium. Slopes range from 0 to 15 percent. Elevation is 700 

to 1,600 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typical pedon of Cleman very fine sandy loam, 0 to 2 

percent slopes, about 6 miles southeast of Moxee City, 

about 680 feet west and 100 feet north of the southeast 

corner of sec. 13, T. 12 N., R. 20 E. 

Ap-0 to 10 inches; brown (10YR 5/3) very fine sandy loam, 

dark brown (10YR 3/3) moist; weak fine granular 

structure; soft, very friable, slightly sticky and slightly 

plastic; few very fine roots; common fine pores; mildly 

alkaline; clear wavy boundary. 

C1-10 to 25 inches; brown (10YR 5/3) fine sandy loam, 

dark brown (10YR 3/3) moist; massive; soft, very friable, 

nonsticky and nonplastic; few medium roots; mildly 

alkaline; abrupt wavy boundary. 

C2-25 to 28 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; massive; soft, very friable, 

nonsticky and nonplastic; mildly alkaline; abrupt 

wavy boundary. 
C3-28 to 40 inches; yellowish brown (10YR 5/4) sandy 

loam, dark yellowish brown (10YR 3/4) moist; 

massive; soft, very friable, nonsticky and 

nonplastic; mildly alkaline; clear wavy boundary. 

C4-40 to 45 inches; brown (10YR 5/3) fine sandy loam, 

dark brown (10YR 3/3) moist; massive; soft, very 

friable, nonsticky and nonplastic; mildly alkaline; 

clear wavy boundary. 

C5-45 to 55 inches; yellowish brown (10YR 5/4) sandy

loam, dark yellowish brown (10YR 3/4) moist; single

grain; loose; mildly alkaline; abrupt wavy boundary. 

C6-55 to 60 inches; yellowish brown (1OYR 5/4) very fine 

sandy loam, dark yellowish brown (10YR 3/4) moist; 

massive; soft, very friable, slightly sticky and 

nonplastic; mildly alkaline. 

Thickness of the mollic epipedon is 7 to 20 inches. 

The profile is neutral or mildly alkaline. The control 

section is 0 to 5 percent coarse fragments. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when moist or dry. 

The C horizon has hue of 10YR or 2.5Y, value of 5 or 6 

when dry and 3 or 4 when moist, and chroma of 2 to 4 

when moist or dry. It is stratified silt loam to sandy loam 

above a depth of 40 inches. Below a depth of 40 inches the 

horizon is stratified silt loam to loamy fine sand and is 0 to 15 

percent rock fragments. 

Clint series 

The Clint series consists of moderately deep, well drained 

soils on uplands. These soils formed in loess and in 

residuum derived from basalt. Slopes range from 8 to 75 

percent. Elevation is 2,300 to 3,300 feet. The average 

annual precipitation is 15 to 18 inches, the average annual 

air temperature is about 49 degrees F, and the average 

frost-free season is 120 to 135 days. 

Typical pedon of Clint very stony loam, 15 to 45 

percent slopes, about 7 miles west of Cowiche, about 

1,000 feet east and 1,200 feet south of the northwest 

corner of sec. 29, T. 14 N., R. 16 E. 

A11-0 to 6 inches; reddish brown (5YR 5/3) very stony 

loam, dark reddish brown (5YR 3/3) moist; moderate 

fine granular structure; slightly hard, friable, slightly sticky 

and slightly plastic; many very fine roots; 10 percent 

pebbles, 5 percent cobbles, and 10 percent stones; 

neutral; clear wavy boundary. 

A12-6 to 10 inches; reddish brown (5YR 5/3) gravelly 

loam, dark reddish brown (5YR 3/3) moist; moderate 

medium subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; many very 

fine roots; few fine tubular pores; 15 percent pebbles 

and 5 percent cobbles; neutral; abrupt wavy boundary. 

B2-10 to 19 inches; reddish brown (5YR 5/3) very gravelly 

loam, dark reddish brown (5YR 3/3) moist; moderate 

medium subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; many very fine 

roots; few fine tubular pores; 40 percent pebbles and 

10 percent cobbles; neutral; abrupt irregular boundary. 

C1-19 to 28 inches; dark brown (7.5YR 4/2) extremely 

gravelly loam, dark brown (7.5YR 3/2) moist; massive; 

slightly hard, friable, slightly sticky and slightly plastic; 

common very fine roots matted between rock 

fragments; 60 percent pebbles and 15 percent cobbles; 

neutral; abrupt wavy boundary. 

R-28 inches; fractured basalt. 

Thickness of the solum is 13 to 20 inches. Depth to 

basalt is 20 to 40 inches. Thickness of the mollic epipedon 

is 10 to 15 inches. The control section is 18 to 25 percent 

clay and 40 to 70 percent coarse fragments. Base saturation 

is more than 75 percent. 

The A horizon has hue of 5YR or 7.5YR, value of 4 or 5 

when dry and 2 or 3 when moist, and chroma of 2 or 3 

when moist or dry. 

The B horizon has hue of 5YR or 7.5YR, and it has 

value of 4 or 5 when dry and 2 or 3 when moist. It is 

very gravelly loam or very gravelly silt loam. 

The C horizon has hue of 5YR or 7.5YR, value of 4 or 5 

when dry and 3 or 4 when moist, and chroma of 2 or 3 

when moist or dry. It is extremely gravelly loam, extremely 

gravelly silt loam, or extremely gravelly sandy clay loam. 

Cowiche series 

The Cowiche series consists of very deep, well drained 

soils on uplands. These soils formed in residuum derived 

from sandstone and have a mantle of loess. Slopes range 

from 2 to 30 percent. Elevation is 1,000 to 2,000 feet. The 

average annual precipitation is 9 to 12 inches, the average 

annual air temperature is about 49 degrees F, and the 

average frost-free season is 135 to 160 days. 

Typical pedon of Cowiche loam, 8 to 15 percent slopes, 

about 6 miles northeast of Naches, about 2,000 feet east 

and 1,280 feet south of the northwest corner of sec. 27, T. 

15 N., R. 18 E. 

Ap-0 to 3 inches; grayish brown (10YR 5/2) loam, very dark 

grayish brown (10YR 3/2) moist; moderate very thin 

platy structure; soft, very friable, slightly sticky and 

slightly plastic; many fine roots; neutral; abrupt smooth 

boundary. 

A12-3 to 10 inches; brown (10YR 5/3) loam, dark brown 

(10YR 3/3) moist; weak medium granular structure; soft, 

very friable, slightly sticky and slightly plastic; common 

fine roots; few fine tubular pores; neutral; clear wavy 

boundary. 
B1-10 to 20 inches; brown (10YR 5/3) loam, dark brown 

(10YR 3/3) moist; weak medium prismatic structure; 

slightly hard, friable, sticky and plastic; few fine roots; 

few fine tubular pores; neutral; clear wavy boundary. 

B2t-20 to 29 inches; yellowish brown (10YR 5/4) loam, 

dark yellowish brown (10YR 3/4) moist; moderate 

medium subangular blocky structure; hard, firm, 

sticky and plastic; few fine roots; few fine tubular pores; 

few thin and very thin clay films in pores and on faces 

of peds; neutral; clear wavy boundary. 

B3-29 to 35 inches; pale brown (10YR 6/3) loam, brown 

(10YR 4/3) moist; weak medium subangular blocky 

structure; slightly hard, friable, slightly sticky and 

slightly plastic; few fine roots; few fine tubular pores; 

mildly alkaline; abrupt wavy boundary. 

C1-35 to 45 inches; pale brown (10YR 6/3) very fine sandy 

loam. brown (10YR 4/3) moist; massive; soft, very friable, 

nonsticky and nonplastic; few fine roots; mildly 

alkaline; clear wavy boundary. 

IIC2ca-45 to 60 inches; brown (10YR 5/3) loamy fine sand, 

dark brown (10YR 3/3) moist; massive; hard, firm, 

nonsticky and nonplastic; few fine roots; segregated 

lime on upper boundary of horizon and in root 

channels; violently effervescent; moderately alkaline. 

Thickness of the mollic epipedon is 10 to 20 inches. 

The argillic horizon is 0 to 5 percent coarse fragments 

and 18 to 30 percent clay. 

The A1 horizon has value of 4 or 5 when dry, and it 

has chroma of 2 or 3 when dry or moist. It is neutral or 

mildly alkaline. 

The B2 horizon has value of 5 to 7 when dry, and it has 

chroma of 3 or 4 when dry or moist. It is heavy silt loam, 

heavy loam, clay loam, or sandy clay loam. It is neutral or 

mildly alkaline. 

The C horizon has chroma of 2 or 3 when moist or 

dry. It is loamy fine sand, very fine sandy loam, sandy 

loam, or loamy sand. It is 0 to 15 percent coarse 

fragments. 

Darland series 

The Darland series consists of very deep, well drained 

soils on mountainsides. These soils formed in colluvium 

derived from basalt. Slopes range from 45 to 75 percent. 

Elevation is 5,000 to 6,900 feet. The average annual 

precipitation is 25 to 45 inches, the average annual air 

temperature is about 42 degrees F, and the average length 

of the growing season, at 28 degrees F, is 100 to 120 days. 

Typical pedon of Darland stony loam, 45 to 75 percent 

slopes, about 14 miles west of Tampico, about 2,900 feet 

west and 2,550 feet north of the southeast corner of sec. 

23, T. 12 N., R. 13 E. 

A11-0 to 8 inches; dark yellowish brown (10YR 4/4) stony 

loam, very dark grayish brown (10YR 3/2) moist; 

moderate medium granular structure; slightly hard, 

friable, slightly sticky and slightly plastic; many fine 

roots; few fine pores; stones on 5 percent of surface; 

neutral; abrupt smooth boundary. 

A12-8 to 14 inches; dark brown (10YR 4/3) very gravelly 

loam, very dark grayish brown (10YR 3/2) moist; 

moderate fine and medium granular structure; soft, 

friable, slightly sticky and slightly plastic; common fine 

and medium roots; few fine pores; 35 percent pebbles 

and 5 percent cobbles; neutral; clear wavy boundary. 

A13-14 to 31 inches; dark brown (10YR 4/3) very cobbly 

loam, very dark grayish brown (10YR 3/2) moist; weak 

fine granular structure; soft, very friable, slightly sticky 

and slightly plastic; many fine roots; 35 percent pebbles 

and 25 percent cobbles; slightly acid; clear wavy 

boundary. 

B2-31 to 43 inches; dark yellowish brown (10YR 4/4) 

extremely cobbly loam, brown (10YR 4/3) moist; weak 

fine granular structure; soft, very friable, slightly sticky 

and slightly plastic; many fine roots; 15 percent pebbles 

and 65 percent cobbles; slightly acid; gradual wavy 

boundary. 

C-43 to 60 inches; dark yellowish brown (10YR 4/4) 

extremely cobbly sandy loam, dark brown (10YR 

3/3) moist; single grain; loose; few fine and medium 

roots; 10 percent pebbles, 70 percent cobbles, and 10 

percent stones; slightly acid. 

Thickness of the mollic epipedon is 20 to 33 inches. The 

control section is 40 to 80 percent rock fragments. 

The A horizon has value of 4 or 5 when dry, and it has 

chroma of 2 or 3 when moist. 

The B horizon has value of 4 or 5 when dry. It is very 

gravelly loam, very cobbly loam, or extremely cobbly loam. 

The C horizon has value of 4 or 5 when dry. It is very 

cobbly or extremely cobbly sandy loam. 

Esquatzel series 

The Esquatzel series consists of very deep, well drained 

soils on flood plains. These soils formed in silty alluvium. 

Slopes range from 0 to 5 percent. Elevation is 650 to 1,500 

feet. The average annual precipitation is 6 to 10 inches, the 

average annual air temperature is about 50 degrees F, and 

the average frost-free season is 130 to 160 days. 

Typical pedon of Esquatzel silt loam, 0 to 2 percent 

slopes, about 4 miles northwest of Buena, about 1,340 

feet south and 400 feet east of the northwest corner of 

sec. 6, T. 11 N., R. 20 E. 
Ap1-0 to 4 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak medium granular 

structure; soft, friable, nonsticky and slightly plastic; 

many very fine roots; common fine tubular pores; 

neutral; abrupt smooth boundary. 

Ap2-4 to 8 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak medium subangular 

blocky structure; slightly hard, friable, slightly sticky 

and plastic; many very fine roots; common fine tubular 

pores; neutral; abrupt smooth boundary. 

A13-8 to 17 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak coarse prismatic 

structure; slightly hard, friable, slightly sticky and 

plastic; common very fine roots; common fine tubular 

pores; neutral; gradual wavy boundary. 

C1-17 to 22 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; slightly hard, 

friable, sticky and plastic; few very fine roots; common 

fine tubular pores; mildly alkaline; abrupt wavy 

boundary. 

C2-22 to 46 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; slightly hard, 

friable, sticky and plastic; few very fine roots; common 

fine tubular pores; mildly alkaline; abrupt wavy 

boundary. 

C3-46 to 60 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; slightly hard, friable, 

slightly sticky and plastic; few very fine roots; common 

fine tubular pores; mildly alkaline. 

Thickness of the mollic epipedon ranges from 15 to 20 

inches. Depth to carbonates is 40 to 60 inches. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when moist or dry. 

It is neutral or mildly alkaline. 

The C horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when moist or dry. 

It is silt loam but may be stratified with fine sandy loam 

below a depth of 40 inches. Reaction is mildly alkaline or 

moderately alkaline. 

The Esquatzel soils in this survey area are a taxadjunct 

to the Esquatzel series because they do not have free 

carbonates above a depth of 40 inches. This difference, 

however, does not affect the use and management of the 

soils. 

Fiander series 

The Fiander series consists of very deep, somewhat 

poorly drained, salt- and alkali-affected soils on flood plains. 

These soils formed in alluvium. Slopes range from 0 to 3 

percent. Elevation is 700 to 900 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typical pedon of Fiander silt loam, about 2 miles north of 

Mabton, about 50 feet east and 1,400 feet south of the 

northwest corner of sec. 30, T. 9 N., R. 23 E. 

A1-0 to 2 inches; grayish brown (10YR 5/2) silt loam, very 

dark grayish brown (10YR 3/2) moist; strong very thin 

platy structure; slightly hard, friable, slightly sticky and 

plastic; many fine roots; many fine pores; moderately 

alkaline; abrupt smooth boundary. 

B21t-2 to 9 inches; brown (10YR 5/3) silty clay loam, dark 

brown (10YR 3/3) moist; strong coarse prismatic 

structure; hard, firm, sticky and plastic;

 many fine roots; 

few fine pores; thin continuous clay films on faces of 

peds; slightly effervescent; strongly alkaline; gradual 

wavy boundary. 

B22t-9 to 13 inches; pale brown (10YR 6/3) silty clay 

loam, brown (10YR 4/3) moist; faces of peds are very 

dark brown (10YR 2/2) moist; strong coarse prismatic 

structure; hard, firm, sticky and plastic; many very fine 

roots; few fine pores; thin continuous clay films on faces 

of peds; slightly effervescent; very strongly alkaline; 

gradual wavy boundary. 

B23t-13 to 25 inches; pale brown (10YR 6/3) silty clay 

loam, brown (10YR 4/3) moist; moderate medium 

granular structure; hard, firm, sticky and plastic; few 

very fine roots; few fine pores; thin continuous clay 

films on faces of peds; violently effervescent; very 

strongly alkaline; gradual wavy boundary. 

C1-25 to 50 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; slightly hard, 

friable, sticky and plastic; few very fine roots; violently 

effervescent; strongly alkaline; abrupt smooth 

boundary. 

C2-50 to 60 inches; brown (10YR 5/3) loamy very fine 

sand, dark brown (10YR 3/3) moist; single grain; loose; 

mildly alkaline. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 1 or 2 when dry or moist. 

It is moderately alkaline to very strongly alkaline. 

The B2t horizon has chroma of 2 or 3 when dry or 

moist. It is heavy silt loam or silty clay loam and is 

strongly alkaline or very strongly alkaline. 

The C horizon has chroma of 2 or 3 when dry or moist. 

It is silt loam above a depth of 40 inches and is silt loam 

or loamy very fine sand below a depth of 40 inches. It is 

mildly alkaline to strongly alkaline. 

Finley series 

The Finley series consists of very deep, well drained soils 

on terraces and alluvial fans. These soils formed in old 

alluvium. Slopes range from 0 to 15 percent. Elevation is 

600 to 1,400 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 180 

days. 
Typical pedon of Finley cobbly fine sandy loam, 0 to 5 

percent slopes, about 14 miles north of Sunnyside, about 

1,600 feet south and 1,300 feet west of the northeast corner 

of sec. 24, T. 12 N., R. 22 E. 

A1-0 to 4 inches; brown (10YR 5/3) cobbly fine sandy 

loam, very dark grayish brown (10YR 3/2) moist; weak 

fine granular structure; soft, very friable, nonsticky and 

nonplastic; common fine roots; common very fine 

tubular pores; 5 percent pebbles and 15 percent 

cobbles; mildly alkaline; abrupt smooth boundary. 

A3-4 to 14 inches; brown (10YR 5/3) fine sandy loam, 

very dark grayish brown (10YR 3/2) moist; massive; 

soft, very friable, nonsticky and nonplastic; few very 

fine roots; 5 percent pebbles; mildly alkaline; clear 

wavy boundary. 

B2-14 to 30 inches; yellowish brown (10YR 5/4) very 

gravelly loam, dark yellowish brown (10YR 3/4) moist; 

massive; soft, very friable, slightly sticky and slightly 

plastic; few very fine roots; 45 percent pebbles and 10 

percent cobbles; mildly alkaline; abrupt wavy 

boundary. 

IIC-30 to 60 inches; yellowish brown (10YR 5/4) extremely 

gravelly sand, dark yellowish brown (10YR 3/4) moist; 

single grain; loose; 60 percent pebbles and 15 percent 

cobbles; mildly alkaline. 

Depth to free lime is 14 to 60 inches. The profile is 

mildly alkaline or moderately alkaline. The control section 

is 50 to 75 percent coarse fragments. 

The A horizon has value of 5 to 7 when dry and 3 or 4 

when moist. It is fine sandy loam, cobbly fine sandy loam, or 

silt loam. 

The B horizon has value of 5 to 7 when dry and 3 or 4 

when moist, and it has chroma of 2 to 4 when dry or moist. 

It is very gravelly loam, very gravelly fine sandy loam, 

or extremely cobbly sandy loam. 

The IIC horizon is very gravelly, very cobbly, extremely 

gravelly, or extremely cobbly sand or loamy sand. 

Gorskel series 

The Gorskel series consists of very shallow and shallow, 

well drained soils on uplifted terraces and foot slopes. These 

soils formed in loess and old alluvium. Slopes range from 0 

to 25 percent. Elevation is 1,200 to 3,000 feet. The average 

annual precipitation is 10 to 12 inches, the average annual 

air temperature is about 50 degrees F, and the average 

frost-free season is 120 to 150 days. 

Typical pedon of Gorskel very stony loam, 0 to 25 

percent slopes, about 2 1/2 miles northeast of Naches, 

about 200 feet east and 2,300 feet north of the southwest 

corner of sec. 26, T. 15 N., R. 17 E. 

A1-0 to 5 inches; brown (10YR 5/3) very stony loam, dark 

brown (10YR 3/3) moist; weak medium subangular blocky 

structure; soft, friable, slightly sticky and slightly plastic; 

many fine roots; many fine vesicular pores; 5 percent 

stones, 30 percent cobbles, and 20 percent pebbles; 

mildly alkaline; abrupt wavy boundary. 

B1t-5 to 8 inches; yellowish brown (10YR 5/4) gravelly 

heavy loam, dark brown (10YR 3/3) moist; moderate 

medium subangular blocky structure; soft, friable, 

slightly sticky and plastic; many fine roots; many very 

fine vesicular pores; 25 percent pebbles; few thin clay 

films on faces of peds; mildly alkaline; abrupt wavy 

boundary. 

B2t-8 to 13 inches; dark yellowish brown (10YR 4/4) very 

gravelly clay loam, dark yellowish brown (10YR 3/4) 

moist; strong medium angular blocky structure; hard, 

friable, sticky and plastic; many fine roots; common 

very fine vesicular pores; 40 percent pebbles and 5 

percent cobbles; many moderately thick clay films on 

faces of peds; mildly alkaline; abrupt wavy boundary. 

IICsim-13 inches; indurated, silica-cemented gravelly 

duripan. 

Depth to the duripan is 9 to 15 inches. The mollic 

epipedon is 7 to 9 inches thick. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when dry or moist. 

The B2t horizon has hue of 7.5YR or 10YR, value of 4 or 

5 when dry and 3 or 4 when moist, and chroma of 3 or 4 

when dry or moist. It is very gravelly loam, very gravelly silt 

loam, very gravelly silty clay loam, very gravelly clay loam, or 

very cobbly clay loam. 

Gorst series 

The Gorst series consists of shallow, well drained soils on 

dissected terraces. These soils formed in loess and old 

alluvium. Slopes range from 0 to 30 percent. Elevation is 

1,200 to 2,000 feet. The average annual precipitation is 8 to 

12 inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 150 

days. 

Typical pedon of Gorst loam, 2 to 15 percent slopes, 

about 2 miles southwest of Harwood, about 1,140 feet west 

and 400 feet south of the northeast corner of sec. 33, T. 

13 N., R. 17 E. 

Ap-0 to 7 inches; brown (10YR 5/3) loam, dark brown 

(10YR 3/3) moist; weak medium subangular blocky 

structure; slightly hard, friable, slightly sticky and 

slightly plastic; many fine roots; few fine tubular pores; 

mildly alkaline; abrupt wavy boundary. 
B21-7 to 10 inches; pale brown (10YR 6/3) loam, 

brown (10YR 4/3) moist; moderate medium 

prismatic structure; hard, firm, slightly sticky and 

plastic; few very fine roots; common fine tubular 

pores; 5 percent pebbles and 5 percent cobbles; 

mildly alkaline; clear wavy boundary. 

B22-10 to 15 inches; brown (7.5YR 5/4) loam, dark brown 

(7.5YR 3/4) moist; moderate medium angular blocky 

structure parting to moderate fine blocky; hard, firm, 

slightly sticky and plastic; few very fine roots; many 

very fine tubular pores; 5 percent pebbles and 5 

percent cobbles; mildly alkaline; abrupt smooth 

boundary. 

IICsim-15 inches; indurated, silica-cemented gravelly 

duripan. 

Depth to the duripan is 12 to 20 inches. Thickness of the 

mollic epipedon is 7 to 9 inches. The control section is 18 to 

25 percent clay. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when dry or moist. 

It is loam or cobbly loam. 

The B horizon is silt loam or loam and is 0 to 15 

percent rock fragments. 

Harwood series 

The Harwood series consists of moderately deep, well 

drained soils on highly dissected terraces and uplands. 

These soils formed in loess and old alluvium. Slopes range 

from 0 to 60 percent. Elevation is 1,200 to 2,000 feet. The 

average annual precipitation is 8 to 12 inches, the average 

annual air temperature is about 51 degrees F, and the frostfree season is 135 to 150 days. 

Typical pedon of Harwood loam, 2 to 5 percent slopes, 

about 5 miles southwest of Harwood, about 150 feet south 

and 1,840 feet east of the northwest corner of sec. 31, T. 13 

N., R. 17 E. 

A11-0 to 4 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; moderate thin platy 

structure; slightly hard, friable, slightly sticky and 

slightly plastic; many very fine roots; neutral; abrupt wavy 

boundary. 

A12-4 to 8 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; moderate medium 

platy structure parting to moderate thin platy; hard, 

friable, slightly sticky and slightly plastic; common 

fine roots; few fine tubular pores; mildly alkaline; clear 

wavy boundary. 

B21-8 to 18 inches; brown (10YR 5/3) loam, dark 

brown (10YR 3/3) moist; weak medium prismatic 

structure; slightly hard, friable, slightly sticky and 

slightly plastic; common fine roots; common fine 

tubular pores; 5 percent pebbles; mildly 

alkaline; clear wavy boundary. 

B22-18 to 24 inches; brown (7.5YR 5/4) loam, dark brown 

(7.5YR 3/4) moist; moderate medium prismatic 

structure; hard, firm, slightly sticky and plastic; common 

fine roots; common fine tubular pores; 5 percent 

pebbles; mildly alkaline; clear wavy boundary. 

B23-24 to 26 inches; brown (7.5YR 5/4) loam, dark brown 

(7.5YR 3/4) moist; moderate medium angular blocky 

structure; very hard, very firm, slightly sticky and plastic; 

common fine roots; many fine tubular pores; 5 percent 

pebbles; moderately alkaline; abrupt wavy boundary. 

IIC1-26 to 30 inches; brown (7.5YR 5/4) gravelly loam, 

dark brown (7.5YR 3/4) moist; massive; very hard, very 

firm, sticky and plastic; few fine roots; many fine tubular 

pores; 25 percent pebbles and 5 percent cobbles; silica 

coatings on pebbles; moderately alkaline; abrupt smooth 

boundary. 

IIC2sim-30 inches; indurated, silica-cemented gravelly 

duripan. 

Depth to the duripan is 20 to 40 inches. Thickness of 

the mollic epipedon is 7 to 15 inches. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when moist or dry. 

It is loam, silt loam, or very stony silt loam. 

The B horizon has value of 5 or 6 when dry and 3 or 4 

when moist. It is loam or silt loam. 

The IIC horizon has hue of 10YR or 7.5YR, and it has 

chroma of 3 or 4 when moist or dry. It is gravelly loam or

gravelly silt. 

Hezel series 

The Hezel series consists of very deep, somewhat 

excessively drained soils on terraces. These soils formed in 

lacustrine sediment and have a mantle of eolian sand. Slopes 

range from 0 to 15 percent. Elevation is 650 to 800 feet. The 

average annual precipitation is 6 to 8 inches, the average 

annual air temperature is about 53 degrees F, and the 

average frost-free season is 150 to 180 days. 

Typical pedon of Hezel loamy fine sand, 2 to 15 percent 

slopes, about 5 miles southeast of Sunnyside, about 120 

feet south and 600 feet west of the northeast corner of sec. 

3, T. 9 N., R. 23 E. 

Ap-0 to 6 inches; grayish brown (10YR 5/2) loamy fine 

sand, very dark grayish brown (10YR 3/2) moist; single 

grain; loose; common fine roots; neutral; abrupt smooth 

boundary. 

C1-6 to 16 inches; grayish brown (10YR 5/2) loamy fine 

sand, very dark grayish brown (10YR 3/2) moist; 

single grain; loose; few fine roots; neutral; gradual 

wavy boundary. 
C2-16 to 22 inches; light brownish gray (10YR 6/2) 

loamy fine sand, dark grayish brown (10YR 4/2) 

moist; single grain; loose; few fine roots; mildly 

alkaline; abrupt wavy boundary. 

IIC3-22 to 28 inches; light brownish gray (10YR 6/2) very 

fine sandy loam, dark grayish brown (10YR 4/2) moist; 

massive; soft, very friable, nonsticky and nonplastic; 

few fine roots; few fine pores; violently effervescent; 

moderately alkaline; abrupt wavy boundary. 

lIC5ca-28 to 34 inches; light brownish gray (2.5Y 6/2) 

silt loam, dark grayish brown (2.5Y 4/2) moist; 

moderate thin platy structure; hard, firm, slightly sticky 

and plastic; few fine roots; few fine pores; segregated 

lime; violently effervescent; moderately alkaline; 

abrupt wavy boundary. 

IIC6ca-34 to 60 inches; light brownish gray (2.5Y 6/2) silt 

loam, dark grayish brown (2.5Y 4/2) moist; massive; 

slightly hard, friable, slightly sticky and plastic; few 

fine roots; few fine pores; segregated lime in root 

channels; violently effervescent; moderately alkaline. 

Depth to secondary lime is 20 to 30 inches. The A and C 

horizons have chroma of 2 or 3 when dry or moist. The IIC 

horizon has value of 6 or 7 when dry and 3 or 4 when moist, 

and it has chroma of 1 to 3 when moist or dry. It is stratified 

silt loam, very fine sandy loam, and fine sandy loam. 

Jumpe series 

The Jumpe series consists of very deep, well drained 

soils on mountainsides and long, broad mountain ridges and 

in canyons. These soils formed in residuum and colluvium 

derived from basalt and containing minor amounts of loess 

and volcanic ash. Slopes range from 5 to 65 percent. 

Elevation is 2,800 to 5,800 feet. The average annual 

precipitation is 25 to 40 inches, the average annual air 

temperature is about 42 degrees F, and the average length 

of the growing season, at 28 degrees F, is 135 to 170 days. 

Typical pedon of Jumpe stony loam, 25 to 45 percent 

slopes, about 12 miles west of Tampico, about 250 feet 

east and 500 feet south of the northwest corner of sec. 

23, T. 12 N., R. 13 E. 

O1-2 inches to 0; decomposing forest litter, needles, 

and twigs. 

A1-0 to 3 inches; brown (10YR 4/3) stony loam, dark 

brown (10YR 3/3) moist; moderate fine granular 

structure; soft, friable, slightly sticky and slightly 

plastic; few very fine and fine roots; 5 percent 

stones; slightly acid; clear wavy boundary. 

B21-3 to 19 inches; brown (7.5YR 4/4) extremely cobbly 

loam, dark yellowish brown (10YR 3/4) moist; 

moderate very fine subangular blocky structure; soft, 

friable, slightly sticky and slightly plastic; few very fine 

roots and common fine and medium roots; 15 percent 

pebbles, 40 percent cobbles, and 10 percent stones; 

medium acid; clear wavy boundary. 

B22-19 to 41 inches; dark yellowish brown (10YR 4/4) 

extremely cobbly loam, dark yellowish brown (10YR 3/4) 

moist; moderate fine subangular blocky structure; 

slightly hard, friable, slightly sticky and plastic; few 

very fine and fine roots and common medium roots; 

15 percent pebbles, 35 percent cobbles, and 20 

percent stones; medium acid; clear wavy boundary. 

C-41 to 60 inches; yellowish brown (10YR 5/4) extremely 

cobbly loam, dark yellowish brown (10YR 3/4) moist; 

moderate fine subangular blocky structure; slightly 

hard, friable, slightly sticky and slightly plastic; few fine 

and common medium roots; 30 percent pebbles, 20 

percent cobbles, and 10 percent stones; medium acid. 

The surface layer is 2 to 10 percent stones. The 

control section averages 40 to 70 percent rock 

fragments. 

The A horizon has hue of 7.5YR or 10YR, value of 4 to 

6 when dry and 3 or 4 when moist, and chroma of 2 or 3 

when dry or moist. 

The B2 horizon has value of 4 to 6 when dry and 3 or 4 

when moist, and it has chroma of 3 or 4 when dry or moist. 

It is very cobbly loam or extremely cobbly loam. 

The C horizon has hue of 10YR or 7.5YR, value of 5 or 6 

when dry, and chroma of 3 or 4 when dry or moist. It is 

very cobbly loam or extremely cobbly loam. 

Kiona series 

The Kiona series consists of very deep, well drained 

soils on uplands. These soils formed in loess and in 

colluvium derived from basalt. Slopes range from 15 to 45 

percent. Elevation is 800 to 2,500 feet. The average 

annual precipitation is 7 to 12 inches, the average annual 

air temperature is about 51 degrees F, and the average 

frost-free season is 140 to 200 days. 

Typical pedon of Kiona stony silt loam, 15 to 45 percent 

slopes, about 16 miles northwest of Sunnyside, about 

1,000 feet north and 300 feet west of the southeast corner 

of sec. 12, T. 12 N., R. 23 E. 
A1-0 to 5 inches; brown (10YR 5/3) stony silt loam, dark 

brown (10YR 3/3) moist; moderate thin platy 

structure; soft, very friable, nonsticky and slightly 

plastic; common fine and very fine roots; common 

very fine tubular pores; 5 percent pebbles and 5 

percent stones; moderately alkaline; abrupt wavy 

boundary. 

B2-5 to 14 inches; pale brown (10YR 6/3) very cobbly silt 

loam, brown (10YR 4/3) moist; massive; soft, very 

friable, slightly sticky and slightly plastic; common very 

fine roots; common very fine tubular pores; 10 percent 

pebbles and 40 percent cobbles; moderately 

alkaline; abrupt irregular boundary. 

C1ca-14 to 60 inches; pale brown (10YR 6/3) very cobbly 

silt loam, brown (10YR 4/3) moist; massive; soft, very 

friable, nonsticky and nonplastic; few very fine roots; 10 

percent pebbles and 40 percent cobbles; lime is 

disseminated and segregated in soft masses; violently 

effervescent; moderately alkaline. 

Depth to lime is 12 to 30 inches. The control section 

averages 50 to 75 percent coarse fragments and is silt 

loam, very fine sandy loam, or loam. The profile is mildly 

alkaline or moderately alkaline. 

The A and B horizons have value of 5 to 7 when dry and 

3 to 5 when moist, and they have chroma of 2 or 3 when 

dry or moist. The B horizon is cobbly or very cobbly silt 

loam or loam. 

The C horizon has value of 5 to 7 when dry and 3 to 5 

when moist, and it has chroma of 2 or 3 when dry or moist. 

It is very cobbly or extremely cobbly silt loam, fine sandy 

loam, or loam. 

Kittitas series 

The Kittitas series consists of very deep, somewhat 

poorly drained soils on flood plains. These soils formed in 

mixed alluvium. Slopes range from 0 to 2 percent. 

Elevation is 700 to 1,100 feet. The average annual 

precipitation is 6 to 12 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typical pedon of Kittitas silt loam, about 2 miles northwest 

of Mabton, about 2,200 feet east and 1,100 feet south of 

the northwest corner of sec. 25, T. 9 N., R. 22 E. 

A11-0 to 2 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; weak medium 

subangular blocky structure parting to weak fine 

granular; slightly hard, friable, slightly sticky and plastic; 

many fine roots; slightly effervescent; very strongly 

alkaline; abrupt smooth boundary. 

A12-2 to 19 inches; grayish brown (10YR 5/2) silt loam, 

very dark grayish brown (10YR 3/2) moist; weak 

medium subangular blocky structure parting to 

moderate fine granular; slightly hard, friable, slightly 

sticky and plastic; common fine roots; common fine 

pores; violently effervescent; very strongly alkaline; 

abrupt wavy boundary. 

C1-19 to 30 inches; light brownish gray (10YR 6/2) silt 

loam, dark grayish brown (10YR 4/2) moist; common 

medium mottles that are gray (10YR 5/1) when moist; 

weak medium subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; common fine 

roots; common fine pores; violently effervescent; 

moderately alkaline; abrupt smooth boundary. 

C2-30 to 41 inches; light brownish gray (10YR 6/2) silt 

loam, dark grayish brown (10YR 4/2) moist; massive: 

slightly hard, friable, slightly sticky and slightly plastic; 

few fine roots; common fine pores; violently 

effervescent; moderately alkaline; gradual wavy 

boundary. 

C3-41 to 52 inches; light brownish gray (10YR 6/2) 

very fine sandy loam, dark grayish brown (10YR 4/2) 

moist; massive; slightly hard, very friable, nonsticky 

and slightly plastic; common fine pores; slightly 

effervescent; moderately alkaline; gradual wavy 

boundary. 

C4-52 to 60 inches; light brownish gray (10YR 6/2) fine 

sandy loam, dark grayish brown (10YR 4/2) moist; 

massive; slightly hard, very friable, nonsticky and 

nonplastic; common fine pores; slightly effervescent; 

moderately alkaline. 

The A horizon has value of 3 to 5 when dry, and it has 

chroma of 1 or 2 when moist or dry. It is moderately 

alkaline to very strongly alkaline. 

The C horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when dry or moist. 

It is silt loam or silty clay loam above a depth of 40 inches 

and is fine sandy loam, very fine sandy loam, or silt loam 

below that depth. It is mildly alkaline or moderately alkaline. 

Lickskillet series 

The Lickskillet series consists of shallow, well drained 

soils on uplands. These soils formed in loess and in 

residuum and colluvium derived from basalt. Slopes range 

from 5 to 45 percent. Elevation is 1,500 to 3,200 feet. The 

average annual precipitation is 10 to 12 inches, the average 

annual air temperature is about 48 degrees F, and the 

average frost-free season is 120 to 150 days. 

Typical pedon of Lickskillet very stony silt loam, 5 to 45 

percent slopes, about 10 miles south of Sunnyside, about 

2,500 feet west and 300 feet north of the southeast corner of 

sec. 6, T. 11 N., R. 23 E. 
A11-0 to 3 inches; grayish brown (10YR 5/2) very stony 

silt loam, very dark grayish brown (10YR 3/2) moist; 

moderate fine granular structure; soft, very friable, 

slightly sticky and slightly plastic; many fine and medium 

roots; few fine tubular pores; 5 percent pebbles and 10 

percent stones; neutral; abrupt smooth boundary. 

B1-3 to 8 inches; brown (10YR 5/3) very gravelly silt loam, 

dark brown (10YR 3/3) moist; weak medium 

subangular blocky structure; soft, very friable, 

slightly sticky and slightly plastic; many medium and few 

fine roots; few fine tubular pores; 20 percent pebbles 

and 10 percent cobbles; mildly alkaline; clear wavy 

boundary. 

B21-8 to 12 inches; yellowish brown (10YR 5/4) very 

gravelly loam, dark yellowish brown (10YR 3/4) moist; 

moderate fine prismatic structure; slightly hard, friable, 

slightly sticky and slightly plastic; common medium 

roots; few fine tubular pores; 25 percent pebbles and 

10 percent cobbles; mildly alkaline; abrupt wavy 

boundary. 

B22-12 to 20 inches; yellowish brown (10YR 5/4) very 

cobbly loam, dark yellowish brown (10YR 3/4) moist; 

moderate fine subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; few medium 

roots; few fine tubular pores; 30 percent pebbles and 30 

percent cobbles; mildly alkaline; abrupt wavy boundary. 

IIR-20 inches; fractured basalt. 

Depth to basalt is 12 to 20 inches. Thickness of the mollic 

epipedon is 7 to 12 inches. The A horizon has value of 4 or 

5 when dry and 2 or 3 when moist. It is silt loam or very 

stony silt loam. The B horizon has value of 5 or 6 when dry 

and 3 or 4 when moist. It is very gravelly loam, very cobbly 

loam, very gravelly silt loam, or very gravelly silty clay loam. 

Logy series 

The Logy series consists of very deep, well drained soils 

on flood plains. These soils formed in alluvium. Slopes 

range from 0 to 5 percent. Elevation is 700 to 1,200 feet. 

The average annual precipitation is 7 to 10 inches, the 

average annual air temperature is about 51 degrees F, 

and the average frost-free season is 130 to 180 days. 

Typical pedon of Logy silt loam, 0 to 2 percent slopes, 

about 4 miles southwest of Wiley City, about 2,550 feet 

south and 80 feet west of the northeast corner of sec. 18, T. 

12 N., R. 17 E. 

A11-0 to 5 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; weak fine 

subangular blocky structure; slightly hard, friable, slightly 

sticky and slightly plastic; common fine roots; common 

fine pores; 5 percent pebbles; neutral; abrupt wavy 

boundary. 

A12-5 to 12 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; weak fine 

subangular blocky structure; slightly hard, friable, slightly 

sticky and slightly plastic; common fine roots; common 

fine pores; 10 percent pebbles; neutral; abrupt wavy 

boundary. 

B2-12 to 33 inches; brown (10YR 4/3) extremely gravelly 

loam, very dark grayish brown (10YR 3/2) moist; 

massive; soft, very friable, slightly sticky and slightly 

plastic; common fine roots; common fine pores; 45 

percent pebbles and 20 percent cobbles; mildly 

alkaline; gradual wavy boundary. 

IIC1-33 to 45 inches; brown (10YR 4/3) extremely cobbly 

coarse sand, very dark grayish brown (10YR 3/2) moist; 

massive; soft, very friable, nonsticky and nonplastic; 

few fine roots; 40 percent pebbles and 40 percent 

cobbles; mildly alkaline; gradual wavy boundary. 

IIC2-45 to 60 inches; grayish brown (10YR 5/2) 

extremely gravelly coarse sand, very dark 

grayish brown (10YR 3/2) moist; single grain; loose; 

55 percent pebbles and 20 percent cobbles; neutral. 

Thickness of the mollic epipedon is 10 to 20 inches. 

The profile is neutral or mildly alkaline. The control section 

averages 50 to 80 percent coarse fragments. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 1 or 2 when dry or moist. It 

is silt loam or cobbly silt loam. It is 5 to 25 percent coarse 

fragments. 

The B horizon has value of 4 or 5 when dry and 3 or 4 

when moist. It is extremely gravelly loam or very gravelly silt 

loam. 

The IIC horizon has value of 3 or 4 when moist, and it 

has chroma of 2 to 4 when dry or moist. 

Loneridge series 

The Loneridge series consists of very deep, well drained 

soils on mountainsides, ridges, benches, and smooth 

mountaintops. These soils formed in residuum and colluvium 

derived from basalt and containing a small amount of loess. 

Slopes range from 0 to 45 percent. Elevation is 2,400 to 

5,400 feet. The average annual precipitation is 25 to 40 

inches, the average annual air temperature is about 42 

degrees F, and the average length of the growing season, at 

28 degrees F, is 135 to 170 days. 

Typical pedon of Loneridge stony loam, 0 to 25 

percent slopes, about 7 miles northwest of Tampico, 
about 800 feet south and 1,700 feet east of the 

northwest corner of sec. 30, T. 13 N., R. 15 E. 

O1-1 inch to 0; decomposing forest litter, needles, and 

twigs. 

A-0 to 3 inches; dark grayish brown (10YR 4/2) stony 

loam, very dark grayish brown (10YR 3/2) moist; weak 

fine granular structure; soft, very friable, nonsticky and 

nonplastic; common very fine roots; 10 percent 

pebbles, 5 percent cobbles, and 5 percent stones; 

medium acid; abrupt smooth boundary. 

B11-3 to 13 inches; pale brown (10YR 6/3) very cobbly 

loam, dark brown (10YR 3/3) moist; weak fine 

subangular blocky structure; slightly hard, friable, slightly 

sticky and slightly plastic; common very fine roots; 20 

percent pebbles and 20 percent cobbles; slightly acid; 

clear smooth boundary. 

B12-13 to 23 inches; pale brown (10YR 6/3) very cobbly 

loam, dark brown (10YR 3/3) moist; moderate fine 

subangular blocky structure; slightly hard, friable, 

slightly sticky and slightly plastic; common very fine 

roots; 35 percent pebbles and 20 percent cobbles; 

slightly acid; clear wavy boundary. 

B21t-23 to 35 inches; dark yellowish brown (10YR 4/4) 

very cobbly clay, dark yellowish brown (10YR 3/4) 

moist; moderate medium subangular blocky structure; 

hard, firm, sticky and plastic; common very fine and 

fine roots and few coarse roots; many thick clay films on 

faces of peds and on rock fragments; 30 percent 

pebbles and 20 percent cobbles; slightly acid; gradual 

wavy boundary. 

B22t-35 to 60 inches; yellowish brown (10YR 5/4) very 

cobbly clay, dark brown (10YR 3/3) moist; moderate 

medium subangular blocky structure; hard, very firm, 

sticky and very plastic; few very fine roots; many thick 

clay films on faces of peds and on rock fragments; 25 

percent pebbles and 30 percent cobbles; slightly acid. 

The control section is 40 to 70 percent rock fragments. 

The A horizon has hue of 7.5YR or 10YR, value of 2 or 3 

when moist, and chroma of 2 or 3 when dry or moist. The 

B1 horizon has hue of 7.5YR or 10YR, value of 5 or 6 when 

dry and 3 or 4 when moist, and chroma of 2 or 3 when dry 

or moist. It is very cobbly loam or very gravelly loam. The B2t 

horizon has value of 4 to 6 when dry and 3 or 4 when moist. 

It is very cobbly clay, very cobbly clay loam, or very 

gravelly clay. 

McDaniel series 

The McDaniel series consists of very deep, well drained 

soils on uplands. These soils formed in loess and in 

colluvium derived from basalt. Slopes range from 5 to 

65 percent. Elevation is 2,200 to 3,300 feet. The average 

annual precipitation is 15 to 18 inches, the 

average annual air temperature is about 49 degrees F, and 

the frost-free season is 120 to 135 days. 

Typical pedon of McDaniel very stony loam, 30 to 65 

percent slopes, about 6 miles southwest of Cowiche, about 

1,800 feet east and 1,600 feet north of the southwest 

corner of sec. 33, T. 14 N., R. 16 E. 

A11-0 to 8 inches; grayish brown (10YR 5/2) very stony 

loam, very dark grayish brown (10YR 3/2) moist; 

moderate medium granular structure parting to 

moderate fine granular; soft, very friable, nonsticky and 

slightly plastic; many fine roots; many fine tubular 

pores; 20 percent pebbles, 5 percent cobbles, and 5 

percent stones; neutral; clear wavy boundary. 

B21t-8 to 24 inches; brown (7.5YR 5/2) very gravelly clay 

loam, dark brown (7.5YR 3/2) moist; moderate medium 

subangular blocky structure; hard, firm, sticky and 

plastic; common fine roots; few fine tubular pores; 30 

percent pebbles and 10 percent cobbles; few thin clay 

films on faces of peds; neutral; gradual wavy boundary.

B22t-24 to 35 inches; brown (7.5YR 5/4) very cobbly silty 

clay loam, dark brown (7.5YR 3/4) moist; moderate 

medium subangular blocky structure; hard, firm, sticky 

and plastic; few fine roots; many fine tubular pores; 25 

percent pebbles and 35 percent cobbles; few thin clay 

films on faces of peds; neutral; gradual wavy boundary. 

B23t-35 to 60 inches; yellowish brown (10YR 5/4) 

extremely cobbly silty clay loam, dark yellowish brown 

(10YR 3/4) moist; moderate fine granular structure; 

hard, firm, sticky and plastic; few fine roots; 25 

percent pebbles and 50 percent cobbles; few thin clay 

films on faces of peds; neutral. 

The mollic epipedon is 21 to 30 inches thick. The A 

horizon has value of 4 or 5 when dry and 2 or 3 when 

moist. The upper part of the B horizon is very gravelly clay 

loam, very gravelly silty clay loam, or very cobbly silty clay 

loam, and the lower part is extremely cobbly silty clay 

loam, extremely gravelly clay loam, or extremely gravelly 

silty clay loam. 

Meystre series 

The Meystre series consists of very deep, well drained 

soils on uplands. These soils formed in loess and in material 

derived from sandstone. Slopes range from 0 to 45 percent. 

Elevation is 2,200 to 3,300 feet. The average annual 

precipitation is 15 to 20 inches, the average annual air 

temperature is about 48 degrees F, and the average length 

of the growing season, at 28 degrees F, is 150 to 175 days.

Typical pedon of Meystre loam, 0 to 15 percent slopes, 

about 12 miles northwest of Naches, about 2,500 
feet east and 1,900 feet south of the northwest corner of 

sec. 2, T. 16 N., R. 16 E. 

O1-1 inch to 0; decaying forest litter. 

A11-0 to 3 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; moderate medium 

platy structure; soft, very friable, nonsticky and slightly 

plastic; common fine roots; slightly acid; abrupt smooth 

boundary. 

A1 2-3 to 11 inches; dark grayish brown (10YR 4/2) 

loam, very dark brown (10YR 2/2) moist; weak 

medium subangular blocky structure; slightly hard, 

friable, nonsticky and slightly plastic; common fine 

roots; slightly acid; clear wavy boundary. 

B21t-11 to 18 inches; brown (10YR 5/3) clay loam, dark 

brown (10YR 3/3) moist; moderate medium 

subangular blocky structure; hard, firm, sticky and 

plastic; common fine roots; few fine tubular pores; few 

thin patchy clay films on faces of peds; slightly acid; 

clear wavy boundary. 

B22t-18 to 29 inches; yellowish brown (10YR 5/4) clay loam, 

dark yellowish brown (10YR 3/4) moist; moderate 

medium subangular blocky structure; hard, firm, 

sticky and plastic; few fine roots; few fine tubular pores; 

few thin patchy clay films on faces of peds; slightly 

acid; clear wavy boundary. 

B3t-29 to 41 inches; light yellowish brown (10YR 6/4) fine 

sandy loam, dark yellowish brown (10YR 4/4) moist; 

weak medium subangular blocky structure; very hard, 

friable, nonsticky and nonplastic; very few medium 

roots; few fine tubular pores; very few thin patchy clay 

films in root channels; neutral; abrupt smooth boundary. 

C-41 to 60 inches; light yellowish brown (10YR 6/4) fine 

sandy loam, dark yellowish brown (10YR 4/4) moist; 

massive; very hard, friable, nonsticky and nonplastic; 

very few medium roots; few fine tubular pores; neutral. 

The mollic epipedon is 10 to 18 inches thick. The control 

section is 0 to 5 percent coarse fragments. The A horizon is 

loam or stony loam. The B2 horizon is clay loam or loam. 

The C horizon has chroma of 3 or 4 when moist. It is fine 

sandy loam or sandy loam. 

Mikkalo series 

The Mikkalo series consists of moderately deep, well 

drained soils on uplands. These soils formed in loess. 

Slopes range from 0 to 15 percent. Elevation is 1,200 to 

2,500 feet. The average annual precipitation is 9 to 12 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 130 to 180 

days. 

Typical pedon of Mikkalo silt loam, 0 to 5 percent 

slopes, about 11 miles south of Mabton, about 100 feet 

west and 200 feet north of the southeast corner of sec. 31, 

T. 7 N., R. 23 E. 

Ap-0 to 5 inches; brown (10YR 5/3) silt loam, dark brown 

(10YR 3/3) moist; weak fine granular structure; soft, 

friable, nonsticky and slightly plastic; many fine roots; 

common fine pores; neutral; abrupt smooth boundary. 

B2-5 to 20 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak coarse prismatic 

structure; soft, friable, nonsticky and slightly plastic; 

common fine roots; common fine pores; mildly alkaline; 

abrupt wavy boundary. 

C1ca-20 to 26 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; soft, friable, slightly 

sticky and slightly plastic; common fine roots; common 

fine pores; 5 percent pebbles; violently effervescent; 

moderately alkaline; abrupt wavy boundary. 

C2ca-26 to 30 inches; pale brown (10YR 6/3) gravelly silt 

loam, brown (10YR 4/3) moist; massive; slightly hard, 

friable, slightly sticky and slightly plastic; common fine 

roots; common fine pores; 20 percent pebbles; 

disseminated and segregated lime in root channels and 

as soft masses; violently effervescent; strongly 

alkaline; abrupt wavy boundary. 

IIR-30 inches; basalt; lime and silica coatings on 

fractured basalt fragments. 

Depth to basalt is 20 to 40 inches. Depth to secondary 

lime is 20 to 35 inches. The A horizon has value of 4 or 5 

when dry, and it has chroma of 2 or 3 when dry or moist. The 

B horizon is neutral or mildly alkaline. The C horizon has 

value of 3 or 4 when moist, and it has chroma of 3 or 4 when 

dry or moist. 

Mippon series 

The Mippon series consists of very deep, well drained 

soils on low terraces and flood plains. These soils formed in 

recent alluvium. Slopes range from 0 to 5 percent. Elevation 

is 2,400 to 4,800 feet. The average annual precipitation is 

20 to 40 inches, the average annual air temperature is about 

43 degrees F, and the average frost-free season is 145 to 

170 days. 

Typical pedon of Mippon very cobbly silt loam, about 5 

miles northwest of Tampico, about 2,200 feet south and 

3,700 feet west of the northeast corner of sec. 14, T. 13 N., 

R. 15 E. 

O1-1/2 inch to 0; decomposed and decomposing 

forest litter. 
A11-0 to 7 inches; very dark grayish brown (10YR 3/2) 

very cobbly silt loam, black (10YR 2/1) moist; weak fine 

subangular blocky structure; soft, very friable, slightly 

sticky and slightly plastic; common very fine roots; very 

few very fine irregular pores; 25 percent pebbles and 35 

percent cobbles; neutral; abrupt wavy boundary. 

A12-7 to 14 inches; dark grayish brown (10YR 4/2) very 

cobbly loam, very dark grayish brown (10YR 3/2) moist; 

weak fine subangular blocky structure; soft, very 

friable, slightly sticky and slightly plastic; common 

very fine and few medium roots; 35 percent pebbles 

and 25 percent cobbles; slightly acid; abrupt wavy 

boundary. 

C1-14 to 22 inches; brown (10YR 4/3) extremely gravelly 

sand, dark brown (10YR 3/3) moist; single grain; 

loose; common very fine roots; 55 percent pebbles and 

25 percent cobbles; slightly acid; gradual wavy 

boundary. 

C2-22 to 60 inches; yellowish brown (10YR 5/4) 

extremely gravelly sand, dark brown (10YR 3/3) 

moist; single grain; loose; few coarse roots; 70 

percent pebbles and 20 percent cobbles; slightly 

acid. 

The mollic epipedon is 10 to 14 inches thick. The 

control section averages 50 to 90 percent rock 

fragments. 

The A horizon has value of 3 to 5 when dry, and it has 

chroma of 1 to 3 when moist or dry. It is 35 to 60 percent 

rock fragments. 

The C horizon has chroma of 3 or 4 when dry and 2 or 3 

when moist. It is 60 to 90 percent rock fragments. It is very 

gravelly sandy loam, very cobbly loam, or very gravelly sand 

in the upper part and is extremely cobbly loamy sand, 

extremely gravelly sand, or very cobbly sand in the lower 

part. 

Moxee series 

The Moxee series consists of shallow, well drained soils on 

uplands. These soils formed in loess overlying a lime- and 

silica-cemented duripan. Slopes range from 0 to 30 

percent. Elevation is 1,300 to 2,000 feet. The average 

annual precipitation is 8 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 125 to 160 days. 

Typical pedon of Moxee silt loam, 2 to 15 percent 

slopes, about 4 miles northeast of Moxee City, about 

100 feet north and 110 feet west of the southeast corner of 

sec. 34, T. 13 N., R. 20 E. 

A11-0 to 3 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak medium platy structure; 

soft, very friable, nonsticky and slightly plastic; 

common fine roots; few fine tubular pores; 5 percent 

pebbles; neutral; abrupt wavy boundary. 

A12-3 to 7 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak medium subangular 

blocky structure; soft, very friable, nonsticky and 

slightly plastic; common fine roots; few fine tubular 

pores; 3 percent pebbles; mildly alkaline; abrupt wavy 

boundary. 

B2-7 to 11 inches; pale brown (10YR 6/3) silt loam, brown 

(10YR 4/3) moist; weak medium subangular blocky 

structure; slightly hard, friable, nonsticky and . slightly 

plastic; common fine roots; few fine tubular pores; 5 

percent pebbles and 5 percent cobbles; moderately 

alkaline; gradual wavy boundary. 

IIC1ca-11 to 18 inches; pale brown (10YR 6/3) gravelly silt 

loam, brown (10YR 4/3) moist; massive; soft, very 

friable, nonsticky and slightly plastic; few fine roots; 20 

percent pebbles and 5 percent cobbles; soft masses of 

lime; strongly effervescent; moderately alkaline; abrupt 

wavy boundary. 

IIC2casim-18 inches; lime- and silica-cemented duripan. 

Depth to the duripan is 10 to 20 inches. The duripan is 

underlain by basalt at a depth of 20 inches or more. The 

mollic epipedon is 7 to 10 inches thick. The control section 

averages 10 to 35 percent coarse fragments and is 5 to 10 

percent clay. The coarse fragments are lime- and silicacemented material and basalt. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when moist or dry. 

It is silt loam or cobbly silt loam and is 0 to 30 percent 

coarse fragments. 

The B horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 3 or 4 when moist or dry. 

The Cca horizon has value of 5 to 8 when dry and 3 to 6 

when moist, and it has chroma of 1 to 4 when moist or dry. 

It is silt loam or gravelly silt loam. 

Naches series 

The Naches series consists of very deep, well drained 

soils on stream terraces in valleys. These soils formed in 

old alluvium. Slopes range from 0 to 2 percent. Elevation is 

700 to 900 feet. The average annual precipitation is 7 to 9 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 130 to 180 

days. 

Typical pedon of Naches loam, about 1/2 mile north of 

Gleed, about 700 feet east and 100 feet south of the 

northwest corner of sec. 32, T. 13 N., R. 18 E. 

Ap-0 to 9 inches; grayish brown (1YR 5/2) loam, very dark 

grayish brown (10YR 3/2) moist; weak fine subangular 

blocky structure; slightly hard, firm, slightly sticky and 

slightly plastic; many fine roots; many fine tubular pores; 

neutral; clear wavy boundary. 
B21t-9 to 16 inches; brown (10YR 5/3) heavy loam, dark 

brown (10YR 3/3) moist; moderate medium angular 

blocky structure; hard, firm, sticky and plastic; 

common fine roots and few medium roots; common 

fine tubular pores; common thin clay films on faces of 

peds; mildly alkaline; gradual wavy boundary. 

B22t-16 to 21 inches; brown (10YR 5/3) heavy loam, 

dark brown (10YR 3/3) moist; moderate medium 

angular blocky structure; hard, friable, sticky and 

plastic; few medium roots and common fine roots; 

common fine tubular pores; common thin clay films on 

faces of peds; mildly alkaline; gradual wavy boundary. 

B3-21 to 28 inches; yellowish brown (10YR 5/4) loam, 

dark yellowish brown (10YR 3/4) moist; weak fine 

subangular blocky structure; slightly hard, friable, 

slightly sticky and slightly plastic; few medium roots and 

common fine roots; few fine tubular pores; mildly 

alkaline; clear wavy boundary. 

C1-28 to 34 inches; yellowish brown (10YR 5/4) 

gravelly loam, dark yellowish brown (10YR 3/4) 

moist; massive; soft, friable, slightly sticky and 

slightly plastic; few medium and fine pores; 30 

percent pebbles; mildly alkaline; abrupt wavy 

boundary. 

IIC2-34 to 60 inches; dark grayish brown (10YR 4/2) 

extremely gravelly sand, very dark grayish brown 

(10YR 3/2) moist; single grain; loose; few very fine roots; 

60 percent pebbles and 15 percent cobbles; mildly 

alkaline. 

Thickness of the mollic epipedon is 7 to 16 inches. 

Depth to the IIC horizon is 25 to 38 inches. 

The A horizon has hue of 10YR or 7.5YR, value of 4 or 5 

when dry and 2 or 3 when moist, and chroma of 2 or 3 

when dry or moist. 

The B2t horizon has hue of 10YR or 7.5YR, and it has value 

of 4 or 5 when dry and 3 or 4 when moist. It is heavy loam, 

sandy clay loam, or clay loam. 

The C horizon has value of 4 to 6 when dry and 3 or 4 

when moist, and it has chroma of 2 to 4 when dry or moist. 

It is fine sandy loam, silt loam, or gravelly loam. 

The IIC horizon is extremely gravelly loamy sand or 

extremely gravelly sand. 

Naxing series 

The Naxing series consists of very deep, well drained 

soils on mountains and broad mountain ridges. These 

soils formed in colluvium derived dominantly from basalt and 

containing volcanic ash and loess. Slopes range from 5 to 65 

percent. Elevation is 5,000 to 7,000 feet. The average 

annual precipitation is 40 to 50 inches, the average annual 

air temperature is about 41 degrees F, and the average 

length of the growing season, at 28 degrees F, is 80 to 110 

days. 

Typical pedon of Naxing stony loam, 25 to 45 percent 

slopes, about 11 miles northwest of Tampico, about 2,300 

feet west and 1,100 feet south of the northeast corner of 

sec. 5, T. 12 N., R. 14 E. 

O1-1 inch to 0; decomposing forest litter. 

A11-0 to 7 inches; brown (10YR 4/3) stony loam, dark 

brown (10YR 3/3) moist; moderate fine granular 

structure; soft, very friable, nonsticky and nonplastic; 

weakly smeary; few coarse roots and common very 

fine, fine, and medium roots; stones on 5 percent of 

surface; medium acid; abrupt wavy boundary. 

A12-7 to 14 inches; brown (10YR 4/3) cobbly loam, dark 

brown (10YR 3/3) moist; moderate fine subangular blocky 

structure parting to moderate fine granular; soft, very 

friable, nonsticky and nonplastic; weakly smeary; many 

fine roots and common medium and coarse roots; 5 

percent pebbles, 20 percent cobbles, and 5 percent 

stones; medium acid; clear smooth boundary. 

B2-14 to 21 inches; yellowish brown (10YR 5/4) very 

cobbly loam, dark yellowish brown (10YR 3/4) moist; 

moderate medium subangular blocky structure parting to 

moderate fine subangular blocky; soft, very friable, 

nonsticky and nonplastic; weakly smeary; few coarse 

roots and common fine and medium roots; 5 percent 

pebbles, 30 percent cobbles, and 15 percent stones; 

medium acid; clear smooth boundary. 

C1-21 to 31 inches; yellowish brown (10YR 5/4) extremely 

cobbly loam, dark yellowish brown (10YR 4/4) moist; 

moderate medium subangular blocky structure parting to 

moderate fine subangular blocky; soft, very friable, 

slightly sticky and nonplastic; weakly smeary; few fine 

and common medium roots; 20 percent pebbles, 40 

percent cobbles, and 5 percent stones; medium acid; 

clear smooth boundary. 

C2-31 to 60 inches; yellowish brown (10YR 5/4) extremely 

cobbly loam, dark yellowish brown (10YR 4/4) moist; 

moderate medium subangular blocky structure; soft, 

very friable, slightly sticky and nonplastic; few coarse 

roots; 20 percent pebbles, 40 percent cobbles, and 5 

percent stones; medium acid. 

The control section averages 40 to 70 percent rock 

fragments. 

The A horizon has hue of 7.5YR or 10YR, value of 4 or 

5 when dry and 2 or 3 when moist, and chroma of 2 or 3 

when moist or dry. It is loam or stony loam. 

The B horizon has hue of 7.5YR or 10YR, value of 5 or 6 

when dry and 3 or 4 when moist, and chroma of 3 or 4 

when moist or dry. It is very cobbly loam or very cobbly 

sandy loam. 

The C horizon has hue of 7.5YR or 10YR, value of 5 or 6 

when dry and 3 or 4 when moist, and chroma of 4 
or 5 when dry or moist. It is very cobbly loam, very 

cobbly sandy loam, or extremely cobbly loam. 

Odo series 

The Odo series consists of very deep, well drained soils 

on uplands. These soils formed in residuum and colluvium 

derived dominantly from basalt and containing some loess 

and volcanic ash. Slopes range from 5 to 35 percent. 

Elevation is 2,000 to 3,200 feet. The average annual 

precipitation is 15 to 19 inches, the average annual air 

temperature is about 46 degrees F, and the average length 

of the growing season, at 28 degrees F, is 150 to 180 days. 

Typical pedon of Odo cobbly silt loam, 5 to 35 percent 

slopes, about 4 miles southwest of Tampico, about 1,300 

feet north and 100 feet east of the southwest corner of sec. 

22, T. 12 N., R. 15 E. 

O1-3 inches to 0; decomposing forest litter. 

A1-0 to 18 inches; brown (10YR 4/3) cobbly silt loam, very 

dark grayish brown (10YR 3/2) moist; moderate very fine 

granular structure; soft, very friable, slightly sticky and 

slightly plastic; many very fine roots and common fine 

roots; many very fine irregular pores; 10 percent pebbles 

and 10 percent cobbles; slightly acid; clear wavy 

boundary. 

B21-18 to 32 inches; yellowish brown (10YR 5/4) gravelly 

loam, dark brown (10YR 3/3) moist; moderate medium 

subangular blocky structure; slightly hard, friable, 

slightly sticky and slightly plastic; common medium and 

fine roots; many very fine irregular pores; 30 percent 

pebbles; slightly acid; clear wavy boundary. 

B22-32 to 60 inches; yellowish brown (10YR 5/4) 

gravelly loam, dark brown (10YR 3/3) moist; weak 

fine granular structure; soft, very friable, nonsticky and 

nonplastic; common fine roots; many very fine 

irregular pores; 20 percent pebbles; slightly acid. 

The mollic epipedon is 12 to 18 inches thick. The control 

section averages 15 to 30 percent coarse fragments. The 

A horizon has hue of 7.5YR or 10YR, and it has value of 3 

or 4 when dry. The B horizon has hue of 5YR, 7.5YR, or 

10YR, and it has value of 4 or 5 when dry. 

Outlook series 

The Outlook series consists of very deep, somewhat 

poorly drained soils on flood plains. These soils formed in 

alluvium. Slopes range from 0 to 3 percent. Elevation is 650 

to 2,000 feet. The average annual precipitation is 6 to 12 

inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 130 to 160 

days. 

Typical pedon of Outlook silt loam, about 2 miles northeast 

of Outlook, about 1,900 feet west and 2,600 

feet south of the northeast corner of sec. 24, T. 10 N., R. 

21 E. 

Ap1-0 to 2 inches; very dark brown (10YR 2/2) silt 

loam, grayish brown (10YR 5/2) dry; weak fine granular 

structure; soft, very friable, nonsticky and slightly 

plastic; many fine roots; violently effervescent; 

strongly alkaline; abrupt wavy boundary. 

Ap2g-2 to 4 inches; very dark grayish brown (2.5Y 3/2) silt 

loam, grayish brown (2.5Y 5/2) dry; few fine distinct 

dark yellowish brown (10YR 4/4) mottles; weak fine 

granular structure; soft, very friable, nonsticky and 

slightly plastic; many fine roots; violently effervescent; 

strongly alkaline; clear wavy boundary. 

A3g-4 to 8 inches; dark grayish brown (2.5Y 4/2) silt 

loam, light brownish gray (2.5Y 6/2) dry; common fine 

distinct dark yellowish brown (10YR 4/4) mottles; weak 

medium granular structure; soft, very friable, nonsticky 

and slightly plastic; many fine roots; violently 

effervescent; strongly alkaline; clear wavy boundary. 

B2g-8 to 18 inches; grayish brown (10YR 5/2) silt loam, 

light gray (10YR 7/2) dry; common medium distinct 

yellowish brown (10YR 5/4) mottles; weak medium 

subangular blocky structure; slightly hard, friable, 

nonsticky and slightly plastic; few very fine roots; few 

fine tubular pores; slightly effervescent; moderately 

alkaline; gradual wavy boundary. 

Cg-18 to 60 inches; dark brown (10YR 3/3) silt loam, 

pale brown (10YR 6/3) dry; common medium distinct 

dark yellowish brown (10YR 4/4) mottles; massive; 

slightly hard, friable, slightly sticky and slightly plastic; 

few very fine roots; few tubular pores; moderately 

alkaline. 

The profile is moderately alkaline or strongly alkaline. 

The 10- to 40-inch control section is very fine sandy loam 

or silt loam. 

The Ap1 horizon has value of 2 or 3 when moist and 4 or 

5 when dry. It is silt loam or fine sandy loam. The Ag 

horizons have mottles that have value of 4 or 5. 

The Bg horizon has value of 3 to 5 when moist and 5 to 

7 when dry. It has mottles that have value of 4 or 5. 

The Cg horizon has value of 3 to 5 when moist and 5 to 

7 when dry. It has mottles that have value of 4 or 5. The 

horizon is silt loam or very fine sandy loam. 

Prosser series 

The Prosser series consists of moderately deep, well 

drained soils on uplands. These soils formed in loess and 

alluvium. Slopes range from 0 to 15 percent. Elevation is 

300 to 1,150 feet. The average annual precipitation is 6 to 

9 inches, the average annual air 
temperature is about 50 degrees F, and the average 

frost-free season is 160 to 180 days. 

Typical pedon of Prosser silt loam, 0 to 15 percent 

slopes, about 11 miles southeast of Mabton, about 2,520 

feet east and 700 feet north of the southwest corner of sec. 

26, T. 7 N., R. 23 E. 

Ap-0 to 4 inches; brown (10YR 5/3) silt loam, dark brown 

(10YR 3/3) moist; weak very fine granular structure; 

soft, very friable, slightly sticky and slightly plastic; 

common very fine and few fine roots; mildly alkaline; 

abrupt smooth boundary. 

B2-4 to 14 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; weak medium subangular 

blocky structure; slightly hard, friable, slightly sticky and 

slightly plastic; common very fine and few fine roots; 

many very fine tubular pores; mildly alkaline; clear 

smooth boundary. 

C1-14 to 19 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; soft, very friable, 

slightly sticky and slightly plastic; common very fine 

roots; common very fine tubular pores; moderately 

alkaline; abrupt wavy boundary. 

C2ca-19 to 24 inches; light gray (10YR 7/2) silt loam, 

grayish brown (10YR 5/2) moist; massive; slightly hard, 

friable, slightly sticky and slightly plastic; few fine roots; 

common very fine tubular pores; mycelial lime; violently 

effervescent; moderately alkaline; abrupt wavy 

boundary. 

C3ca-24 to 33 inches; light gray (10YR 7/2) silt loam, 

grayish brown (10YR 5/2) moist; massive; slightly 

hard, friable, slightly sticky and nonplastic; few fine 

roots; common very fine tubular pores; less than 5 

percent basalt pebbles; mycelial lime; violently 

effervescent; moderately alkaline; abrupt smooth 

boundary. 

IIR-33 inches; lime- and silica-coated basalt. 

Depth to basalt is 20 to 40 inches. The A horizon has 

value of 5 or 6 when dry and 3 or 4 when moist, and it has 

chroma of 2 or 3 when dry or moist. It is neutral to 

moderately alkaline. The B horizon has value of 5 or 6 when 

dry. The C horizon is mildly alkaline or moderately alkaline. 

It is 0 to 10 percent coarse basalt fragments and is silt loam 

or very fine sandy loam. 

Quincy series 

The Quincy series consists of very deep, somewhat 

excessively drained soils on terraces. These soils formed in 

eolian sand. Slopes range from 0 to 10 percent. Elevation is 

650 to 1,100 feet. The average annual precipitation is 6 to 9 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 135 to 180 

days. 

Typical pedon of Quincy loamy fine sand, 0 to 10 

percent slopes, about 4 miles southeast of Sunnyside, 

about 1,320 feet north and 50 feet west of the southeast 

corner of sec. 34, T. 10 N., R. 23 E. 

A1-0 to 20 inches; grayish brown (10YR 5/2) loamy 

fine sand, very dark grayish brown (10YR 3/2) moist; 

single grain; loose; few very fine roots; neutral; 

gradual wavy boundary. 

C2-20 to 60 inches; grayish brown (10YR 5/2) sand, 

very dark grayish brown (10YR 3/2) moist; single 

grain; loose; mildly alkaline. 

The 10- to 40-inch control section is sand to loamy fine 

sand. The profile has value of 4 or 5 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when moist or dry. 

The A horizon is slightly acid to moderately alkaline. The C 

horizon is neutral to moderately alkaline. 

Renslow series 

The Renslow series consists of deep and very deep, well 

drained soils on uplands. These soils formed in loess. 

Elevation is 2,500 to 2,800 feet. Slopes range from 0 to 15 

percent. The average annual precipitation is 10 to 13 inches, 

the average annual air temperature is about 49 degrees F, 

and the average frost-free season is 130 to 150 days. 

Typical pedon of Renslow silt loam, basalt substratum, 5 to 

15 percent slopes, about 13 miles southwest of Mabton, 

about 2,400 feet west and 1,200 feet north of the southeast 

corner of sec. 35, T. 7 N., R. 21 E. 

Ap-0 to 7 inches; grayish brown (10YR 5/2) silt loam, very 

dark grayish brown (10YR 3/2) moist; moderate fine 

granular structure; slightly hard, friable, slightly sticky 

and slightly plastic; very few fine roots; neutral; abrupt 

smooth boundary. 

B1-7 to 23 inches; grayish brown (10YR 5/2) silt loam, very 

dark grayish brown (10YR 3/2) moist; moderate coarse 

prismatic structure; slightly hard, friable, nonsticky and 

slightly plastic; common fine roots; common fine pores; 

mildly alkaline; abrupt smooth boundary. 

B2t-23 to 30 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 4/3) moist; moderate coarse prismatic 

structure; slightly hard, friable, nonsticky and slightly 

plastic; common fine roots; common fine pores; thin 

patchy clay films on faces of peds; moderately alkaline; 

abrupt smooth boundary. 

C1-30 to 33 inches; pale brown (10YR 6/3) silt loam, dark 

brown (10YR 4/3) moist; massive; slightly hard, friable, 

slightly sticky and slightly plastic; common fine roots; 

common fine pores; moderately alkaline; abrupt wavy 

boundary. 

C2-33 to 37 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; hard, firm, slightly 

sticky and slightly plastic; few fine roots; few fine pores; 

10 percent pebbles; violently effervescent; moderately 

alkaline; abrupt wavy boundary. 
C3ca-37 to 44 inches; pale brown (10YR 6/3) gravelly silt 

loam, brown (10YR 4/3) moist; massive; hard, firm, 

slightly sticky and slightly plastic; few fine roots; few fine 

pores; 20 percent pebbles; mycelial lime; violently 

effervescent; moderately alkaline; abrupt smooth 

boundary. 

IIR-44 inches; basalt. 

Depth to secondary carbonates is 25 to 40 inches. 

Depth to basalt is 40 to 60 inches or more. The mollic 

epipedon is 10 to 18 inches thick. 

The Ap horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when dry or moist. It 

is neutral or mildly alkaline. 

The B horizon has value of 4 or 5 when dry. 

The C horizon has value of 5 or 6 when dry and 3 or 4 

when moist. It is moderately alkaline or strongly alkaline. 

Ritzville series 

The Ritzville series consists of deep and very deep, well 

drained soils on uplands. These soils formed in loess. 

Slopes range from 0 to 60 percent. Elevation is 1,200 to 

2,500 feet. The average annual precipitation is 9 to 12 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 130 to 150 

days. 

Typical pedon of Ritzville silt loam, 2 to 5 percent slopes, 

about 7 miles southwest of Mabton, about 3,700 feet west 

and 75 feet south of the northeast corner of sec. 4, T. 7 N., 

R. 23 E. 

Ap-0 to 7 inches; grayish brown (10YR 5/2) silt loam, very 

dark grayish brown (10YR 3/2) moist; moderate fine 

granular structure; slightly hard, friable, slightly sticky and 

slightly plastic; common fine roots; common fine pores; 

neutral; abrupt smooth boundary. 

B2-7 to 26 inches; brown (10YR 5/3) silt loam, very 

dark brown (10YR 3/3) moist; weak coarse 

prismatic structure; slightly hard, friable, 

slightly sticky and slightly plastic; common fine 

roots; common fine pores; mildly alkaline; gradual 

wavy boundary. 

B3-26 to 37 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; slightly hard, 

friable, slightly sticky and slightly plastic; common fine 

roots; common fine pores; mildly alkaline; gradual 

wavy boundary. 

C2ca-37 to 52 inches; light yellowish brown (10YR 6/4) silt 

loam, dark yellowish brown (10YR 4/4) moist; massive; 

slightly hard, friable, slightly sticky and slightly plastic; 

few fine roots; common fine pores; mycelial lime; 

strongly effervescent; moderately alkaline; gradual wavy 

boundary. 

C3ca-52 to 60 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; soft, friable, slightly 

sticky and slightly plastic; few very fine roots; common 

fine pores; disseminated lime; strongly effervescent; 

moderately alkaline. 

The mollic epipedon is 10 to 15 inches thick. Depth to 

secondary carbonates ranges from 30 to 43 inches. The Ap 

horizon has value of 4 or 5 when dry and 2 or 3 when moist, 

and it has chroma of 2 or 3 when moist or dry. The B 

horizon has chroma of 3 or 4 when dry or moist. The C 

horizon has value of 5 or 6 when dry and 4 or 5 when moist. 

It is moderately alkaline or strongly alkaline. 

Ritzville Variant 

The Ritzville Variant consists of very deep, well drained 

soils on terraces. These soils formed in loess overlying 

cobbly or gravelly alluvium. Slopes range from 5 to 15 

percent. Elevation is 1,200 to 1,800 feet. The average 

annual precipitation is 9 to 12 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 150 days. 

Typical pedon of Ritzville Variant silt loam, 5 to 15 

percent slopes, about 9 miles northeast of Sunnyside, 

about 2,030 feet north and 820 feet west of the 

southeast corner of sec. 16, T. 11 N., R. 23 E. 

Ap1-0 to 3 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak fine granular structure; 

slightly hard, friable, slightly sticky and slightly plastic; 

many fine roots; neutral; abrupt smooth boundary. 

Ap2-3 to 7 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak thick platy structure; 

slightly hard, friable, slightly sticky and slightly plastic; 

many fine roots; neutral; abrupt smooth boundary. 

B2-7 to 18 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; weak coarse prismatic structure; 

slightly hard, friable, slightly sticky and slightly plastic; 

many fine roots; 10 percent pebbles; mildly alkaline; 

abrupt smooth boundary. 

IlC1-18 to 28 inches; pale brown (10YR 6/3) gravelly silt 

loam, brown (10YR 4/3) moist; massive; slightly hard, 

friable, slightly sticky and slightly plastic; many fine 

roots; 20 percent pebbles; mildly alkaline; abrupt 

smooth boundary. 

IIC2-28 to 36 inches; pale brown (10YR 6/3) very cobbly 

silt loam, brown (10YR 4/3) moist; massive; soft, very 

friable, slightly sticky and slightly plastic; many fine 

roots; 30 percent cobbles and 10 percent pebbles; 

slightly effervescent; mildly alkaline; clear wavy 

boundary. 
IIC3ca-36 to 39 inches; pale brown (10YR 6/3) very 

cobbly loam, dark yellowish brown (10YR 4/4) moist; 

massive; soft, very friable, slightly sticky and slightly 

plastic; many fine roots; 30 percent cobbles and 10 

percent pebbles; segregated and disseminated lime; 

violently effervescent; moderately alkaline; abrupt wavy 

boundary. 

IIC4ca-39 to 60 inches; light gray (10YR 7/2) very cobbly 

loam, dark grayish brown (10YR 4/2) moist; massive; 

very hard, firm, nonsticky and slightly plastic; few fine 

roots; 30 percent cobbles and 10 percent pebbles; lime 

coatings on coarse fragments; violently effervescent; 

moderately alkaline. 

The mollic epipedon is 8 to 15 inches thick. The Ap 

horizon has value of 4 or 5 when dry and 2 or 3 when 

moist, and it has chroma of 2 or 3 when dry or moist. It is silt 

loam or cobbly silt loam. The B horizon has value of 5 or 6 

when dry and 3 or 4 when moist, and it has chroma of 3 or 

4 when dry or moist. The IIC horizon has value of 5 to 7 

when dry and 4 or 5 when moist. 

Rock Creek series 

The Rock Creek series consists of very shallow and 

shallow, well drained soils on plateaus and ridgetops on 

uplands. These soils formed in loess and in residuum 

derived from basalt. Slopes range from 0 to 45 percent. 

Elevation is 1,200 to 3,200 feet. The annual precipitation is 

10 to 16 inches, the average annual air temperature is 

about 48 degrees F, and the average frost-free season is 

120 to 170 days. 

Typical pedon of Rock Creek very stony silt loam, 0 to 30 

percent slopes, about 400 feet west and 75 feet north of 

the southeast corner of sec. 1, T. 15 N., R. 17 E. 

A1-0 to 2 inches; grayish brown (10YR 5/2) very stony silt 

loam, very dark grayish brown (10YR 3/2) moist; 

moderate fine granular structure; soft, friable, slightly 

sticky and slightly plastic; many very fine and few fine 

roots; stones on 3 percent of surface; 15 percent 

pebbles and 10 percent cobbles; neutral; clear smooth 

boundary. 

B21t-2 to 4 inches; brown (10YR 5/3) very cobbly clay, 

dark brown (10YR 3/3) moist; moderate thin platy 

structure; slightly hard, friable, sticky and plastic; 

common very fine and few fine roots; few fine tubular 

pores; few thin patchy clay films on faces of peds; 20 

percent pebbles and 20 percent cobbles; neutral; abrupt 

smooth boundary. 

B22t-4 to 10 inches; brown (7.5YR 5/4) very cobbly clay, 

 dark brown (7.5YR 3/4) moist; moderate 

medium angular blocky structure; hard, firm, 

sticky and plastic; thick continuous clay films on 

faces of peds; few dark organic stains on faces of 

peds; 30 percent pebbles and 20 percent cobbles; 

neutral; clear smooth boundary. 

R-10 inches; fractured basalt. 

Depth to basalt ranges from 8 to 15 inches. The control 

section is 35 to 45 percent clay and 35 to 90 percent coarse 

fragments. The profile is neutral or Slightly acid. The A 

horizon has hue of 5YR to 10YR, value of 4 or 5 when dry 

and 3 or 4 when moist, and chroma of 2 or 3 when dry or 

moist. The B2t horizon has hue of 5YR or 7.5YR, and it has 

value of 4 or 5 when dry. It is silty clay loam, clay loam, silty 

clay, or clay and is extremely cobbly, extremely 

gravelly, very cobbly, or very gravelly. 

Roza series 

The Roza series consists of very deep, well drained 

soils on uplands. These soils formed in material derived 

from fine textured sediment. Slopes range from 5 to 60 

percent. Elevation is 1,300 to 2,400 feet. The average 

annual precipitation is 8 to 12 inches, the average annual 

air temperature is about 51 degrees F, and the average 

frost-free season is 135 to 150 days. 

Typical pedon of Roza clay loam, 8 to 15 percent slopes, 

about 4 miles north of Selah, about 300 feet east and 120 

feet south of the northwest corner of sec. 14, T. 14 N., R. 18 

E. 

A11-0 to 2 inches; grayish brown (10YR 5/2) clay loam, 

dark grayish brown (10YR 4/2) moist; strong fine and 

very fine granular structure; soft, firm, sticky and plastic; 

common very fine roots; common very fine tubular pores; 

mildly alkaline; abrupt wavy boundary. 

B21-2 to 11 inches; grayish brown (10YR 5/2) heavy clay 

loam, dark grayish brown (10YR 4/2) moist; moderate 

coarse prismatic structure parting to moderate coarse 

angular blocky; very hard, firm, sticky and plastic; 

vertical cracks between peds; common very fine roots; 

many fine and very fine tubular pores; mildly alkaline; 

abrupt wavy boundary. 

B22-11 to 19 inches; light brownish gray (10YR 6/2) silty 

clay, grayish brown (10YR 5/2) moist; strong medium 

prismatic structure parting to strong medium subangular 

blocky; very hard, firm, sticky and plastic; vertical cracks 

between peds; few very fine roots; many fine and very 

fine tubular pores; mildly alkaline; abrupt wavy 

boundary. 
C1-19 to 26 inches; light brownish gray (10YR 6/2) silty 

clay, grayish brown (10YR 5/2) moist; weak coarse 

prismatic structure; hard, firm, sticky and plastic; few very 

fine roots; common fine and very fine tubular pores; 

mildly alkaline; clear wavy boundary. 

C2-26 to 38 inches; pale brown (10YR 6/3) silty clay 

loam, dark grayish brown (10YR 4/2) moist; massive; 

hard, firm, sticky and plastic; few very fine roots; 

common fine and very fine tubular pores; moderately 

alkaline; abrupt wavy boundary. 

C3ca-38 to 45 inches; pale brown (10YR 6/3) silty clay 

loam, dark grayish brown (10YR 4/2) moist; massive; 

very hard, firm, sticky and plastic; few very fine roots; 

common fine tubular pores; mycelial lime; violently 

effervescent; moderately alkaline; clear wavy boundary. 

C4ca-45 to 60 inches; light gray (2.5Y 7/2) clay loam, 

grayish brown (2.5Y 5/2) moist; massive; weakly 

laminated; very hard, very firm, sticky and plastic; 

mycelial lime and coatings of lime on laminations; 

violently effervescent; moderately alkaline. 

Depth to calcareous material is 36 to 60 inches. The 

solum is 16 to 26 inches thick. The profile is 0 to 5 percent 

rock fragments throughout. The control section is 35 to 60 

percent clay. Vertical cracks 1 centimeter to 2 centimeters 

wide extend from the surface to a depth of 19 inches. The A 

horizon has value of 5 or 6 when dry and 4 or 5 when moist, 

and it has chroma of 1 or 2 when dry or moist. The B2 

horizon is heavy clay loam, heavy silty clay loam, silty clay, or 

clay. The C horizon is silty clay loam, silty clay, or clay loam. 

Sapkin series 

The Sapkin series consists of moderately deep, well 

drained soils on uplands and mountainsides. These 

soils formed in loess and in residuum and colluvium derived 

dominantly from basalt. Slopes range from 10 to 75 percent. 

Elevation is 2,800 to 5,600 feet. The average annual 

precipitation is 18 to 35 inches, the average annual air 

temperature is about 43 degrees F, and the average frostfree season 'is 95 to 130 days. 

Typical pedon of Sapkin very stony loam, 10 to 45 percent 

slopes, about 6 miles northeast of Naches, about 100 feet 

east and 900 feet south of the northwest corner of sec. 14, 

T. 15 N., R. 16 E. 

A11-0 to 7 inches; dark grayish brown (10YR 4/2) very 

stony loam, very dark brown (10YR 2/2) moist; 

moderate medium and fine granular structure; 

slightly hard, friable, slightly sticky and slightly 

plastic; many fine and few coarse roots; stones on 15 

percent of surface; slightly acid; clear wavy boundary. 

A12-7 to 15 inches:, brown (7.5YR 5/2) loam, dark brown 

(7.5YR 3/2) moist; moderate fine subangular blocky 

structure; slightly hard, friable, slightly sticky and slightly 

plastic; many fine and coarse roots; 10 percent 

pebbles; slightly acid; clear wavy boundary. 

B1-15 to 27 inches; brown (7.5YR 5/4) cobbly loam, 

dark brown (7.5YR 4/4) gravelly loam, dark brown 

(7.5YR 3/4) moist; moderate medium subangular 

blocky structure; slightly hard, friable, slightly sticky 

and plastic; common fine roots; few fine tubular pores; 

20 percent pebbles and 15 percent cobbles; slightly 

acid; clear wavy boundary. 

B21t-27 to 31 inches; brown (7.5YR 5/4) very cobbly 

loam, dark brown (7.5YR 3/4) moist; moderate fine 

subangular blocky structure; slightly hard, firm, slightly 

sticky and plastic; few fine roots; common fine tubular 

pores; few thin clay films on faces of peds; 20 percent 

cobbles and 15 percent pebbles:, slightly acid; clear 

wavy boundary. 

B22t-31 to 35 inches; brown (7.5YR 5/4) extremely cobbly 

clay loam, dark brown (7.5YR 3/4) moist; weak fine 

subangular blocky structure; hard, firm, sticky and 

plastic; very few fine roots; few fine tubular pores; few 

thin clay films on faces of peds; 70 percent cobbles and 

20 percent pebbles; slightly acid; abrupt wavy boundary.

R-35 inches; basalt. 

Depth to basalt is 20 to 40 inches. The mollic epipedon is 

10 to 18 inches thick. The control section is 40 to 80 

percent rock fragments. The A horizon has hue of 10YR or 

7.5YR, value of 4 or 5 when dry, and chroma of 2 or 3 

when moist. The B2t horizon has hue of 10YR or 7.5YR, 

value of 4 or 5 when dry, and chroma of 3 or 4 when moist 

or dry. It is extremely cobbly loam, very cobbly loam, 

extremely cobbly clay loam, or very cobbly clay loam. 

Saydab series 

The Saydab series consists of moderately deep, 

moderately well drained soils on mountaintops and broad 

ridgetops. These soils formed in residuum derived dominantly 

from basalt and containing volcanic ash and loess. Slopes 

range from 0 to 5 percent. Elevation is 5,500 to 7,000 feet. 

The average annual precipitation is 40 to 50 inches, the 

average annual air temperature is about 41 degrees F, and 

the average length of the growing season, at 28 degrees F, 

is 80 to 110 days. 

Typical pedon of Saydab cobbly loam, 0 to 5 percent 

slopes, about 11 miles west of Tampico, about 2,300 feet 

west and 660 feet south of the northeast corner of sec. 5, 

T. 12 N., R. 14 E. 

O1-1 inch to 0; decomposing forest litter. 
A11-0 to 5 inches; dark brown (10YR 4/3) cobbly loam, 

very dark grayish brown (10YR 3/2) moist; moderate 

fine granular structure; soft, very friable, nonsticky and 

nonplastic; weakly smeary; common coarse roots and 

many very fine, fine, and medium roots; 5 percent 

pebbles and 10 percent cobbles; medium acid; abrupt 

wavy boundary. 

A12-5 to 11 inches; dark brown (10YR 4/3) loam, dark 

brown (10YR 3/3) moist; moderate medium subangular 

blocky structure; soft, very friable, nonsticky and 

nonplastic; weakly smeary; few coarse roots and 

common medium and very fine roots; 5 percent pebbles; 

medium acid; clear smooth boundary. 

B2-11 to 15 inches; yellowish brown (10YR 5/4) very 

cobbly loam, dark yellowish brown (10YR 3/4) moist; 

moderate medium subangular blocky structure; soft, very 

friable, nonsticky and nonplastic; weakly smeary; few 

very fine and medium roots; 10 percent pebbles, 35 

percent cobbles, and 5 percent stones; medium acid; 

clear wavy boundary. 

B3-15 to 27 inches; yellowish brown (10YR 5/4) very 

cobbly loam, dark yellowish brown (10YR 3/4) moist; 

moderate fine subangular blocky structure; soft, very 

friable, nonsticky and nonplastic; few very fine and 

medium roots; 10 percent pebbles, 40 percent cobbles, 

and 5 percent stones; medium acid; abrupt wavy 

boundary. 

R-27 inches; basalt. 

Depth to bedrock is 25 to 30 inches. The control section 

is 40 to 60 percent rock fragments. The A horizon has value 

of 4 or 5 when dry and 2 or 3 when moist, and it has chroma 

of 2 or 3 when dry or moist. The B horizon has value of 3 or 

4 when moist, and it has chroma of 3 or 4 when dry. It is 

very cobbly loam or very cobbly silt loam. 

Scoon series 

The Scoon series consists of shallow, well drained soils on 

uplands. These soils formed in loess overlying a lime- and 

silica-cemented duripan. Slopes range from 2 to 30 

percent. Elevation is 800 to 1,400 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typical pedon of Scoon silt loam, 5 to 8 percent slopes, 

about 5 miles north of Sunnyside, about 200 feet west and 

1,100 feet south of the northeast corner of sec. 36, T. 11 

N., R. 22 E. 

Ap-0 to 6 inches; light brownish gray (10YR 6/2) silt 

loam, dark grayish brown (10YR 4/2) moist; weak fine 

granular structure; slightly hard, friable, 

slightly sticky and slightly plastic; few fine roots; 5 

percent pebbles; mildly alkaline; abrupt smooth 

boundary. 

B2-6 to 10 inches; light brownish gray (10YR 6/2) silt loam, 

dark grayish brown (10YR 4/2) moist; weak coarse 

prismatic structure; slightly hard, friable, slightly sticky 

and slightly plastic; few fine roots; few fine tubular 

pores; 15 percent pebbles; moderately alkaline; gradual 

wavy boundary. 

C1ca-10 to 16 inches; light brownish gray (10YR 6/2) 

gravelly silt loam, dark grayish brown (10YR 4/2) moist; 

slightly hard, friable, slightly sticky and slightly plastic; 

few fine roots; few fine tubular pores; 30 percent 

pebbles; violently effervescent; moderately alkaline; 

abrupt wavy boundary. 

IIC2casim-16 to 60 inches; indurated lime- and silicacemented duripan. 

Depth to the duripan is 10 to 20 inches. The duripan is 

underlain by basalt at a depth of 20 inches or more. The 

control section averages less than 35 percent rock 

fragments. 

The A horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when moist or dry. 

It is 0 to 5 percent rock fragments and is mildly alkaline or 

moderately alkaline. 

The B2 horizon has value of 6 or 7 when dry and 4 or 5 

when moist, and it has chroma of 2 or 3 when dry or moist. 

It is gravelly silt loam, silt loam, or gravelly very fine sandy 

loam. It is mildly alkaline or moderately alkaline. 

The C horizon has value of 6 or 7 when dry and 4 or 5 

when moist. It is gravelly silt loam, loam, or gravelly very fine 

sandy loam. 

Scooteney series 

The Scooteney series consists of very deep, well drained 

soils on terraces. These soils formed in alluvium. Slopes 

range from 0 to 15 percent. Elevation is 650 to 1,300 feet. 

The average annual precipitation is 6 to 9 inches, the 

average annual air temperature is about 51 degrees F, and 

the average frost-free season is 135 to 170 days. 

Typical pedon of Scooteney silt loam, 0 to 2 percent 

slopes, about 1 mile northeast of Mabton, about 600 feet 

north and 50 feet west of the southeast corner of sec. 31, 

T. 9 N., R. 23 E. 

Ap-0 to 6 inches; brown (10YR 5/3) silt loam, dark brown 

(10YR 3/3) moist; moderate fine granular structure; 

slightly hard, friable, nonsticky and slightly plastic; many 

fine roots; many fine pores; neutral; abrupt smooth 

boundary. 

B2-6 to 22 inches; pale brown (10YR 6/3) silt loam, brown 

(10YR 4/3) moist; weak coarse prismatic structure; 

slightly hard, friable, nonsticky and slightly plastic; many 

fine roots; many fine pores; neutral; gradual wavy 

boundary. 
C1ca-22 to 33 inches; light brownish gray (10YR 6/2) 

gravelly fine sandy loam, dark grayish brown (10YR 4/2) 

moist; massive; slightly hard, friable, slightly sticky and 

slightly plastic; many fine roots; many fine pores; 20 

percent pebbles; violently effervescent; moderately 

alkaline; gradual wavy boundary. 

IIC2-33 to 60 inches; light brownish gray (10YR 6/2) very 

gravelly sandy loam, dark grayish brown (10YR 4/2) 

moist; massive; soft, friable, nonsticky and nonplastic; 

few fine roots; few pores; 50 percent pebbles; 

moderately alkaline. 

The control section averages 20 to 35 percent coarse 

fragments. The A horizon has chroma of 2 or 3 when moist 

or dry. It is silt loam or cobbly silt loam. 

The B horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when moist or dry. It 

is silt loam, loam, or very fine sandy loam. It is neutral or 

mildly alkaline. 

The C horizon has value of 4 or 5 when moist and 6 or 7 

when dry, and it has chroma of 2 or 3 when moist or dry. It 

is gravelly fine sandy loam or gravelly silt loam. 

Selah series 

The Selah series consists of moderately deep, well 

drained soils on high, dissected terraces. These soils formed 

in loess and alluvium overlying a lime- and silica-cemented 

duripan. Slopes range from 2 to 30 percent. Elevation is 

1,100 to 1,800 feet. The average annual precipitation is 8 to 

12 inches, the average annual air temperature is about 52 

degrees F, and the average frost-free season is 150 to 180 

days. 

Typical pedon of Selah silt loam, 5 to 8 percent slopes, 

about 1 mile northwest of Selah, about 1,400 feet west and 

700 feet north of the southeast corner of sec. 26, T. 14 N., 

R. 18 E. 

Ap-0 to 4 inches; grayish brown (10YR 5/2) silt loam, very 

dark grayish brown (10YR 3/2) moist; moderate thin platy 

structure; soft, very friable, slightly sticky and slightly 

plastic; many fine roots; few fine tubular pores; neutral; 

abrupt smooth boundary. 

A12-4 to 7 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak medium subangular 

blocky structure; slightly hard, very friable, 

slightly sticky and slightly plastic; common fine roots; 

few fine tubular pores; neutral; clear wavy boundary. 

B1-7 to 13 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak coarse subangular 

blocky structure; slightly hard, friable, slightly 

sticky and slightly plastic; few fine roots; common fine 

tubular pores; mildly alkaline; clear wavy boundary. 

B21t-13 to 24 inches; pale brown (10YR 6/3) heavy silt 

loam, dark brown (10YR 3/3) moist; moderate medium 

prismatic structure; slightly hard, friable, slightly sticky 

and plastic; few fine roots; many fine tubular pores; thin 

patchy siliceous coatings on faces of peds; mildly 

alkaline; clear wavy boundary. 

B22t-24 to 29 inches; light brownish gray (10YR 6/2) 

silty clay loam, dark grayish brown (10YR 4/2) moist; 

moderate medium subangular blocky structure; hard, 

firm, sticky and plastic; few fine roots; common fine 

tubular pores; few thin patchy Clay films on faces of 

peds and in pores; mildly alkaline; abrupt smooth 

boundary. 

B22tca-29 to 34 inches; brown (10YR 5/3) clay loam, 

brown (10YR 4/3) moist; strong medium subangular 

blocky structure; hard, firm, sticky and plastic; few fine 

roots; few fine tubular pores; common thin clay films on 

faces of peds and in pores; lime on faces of peds and 

in veins throughout peds; violently effervescent; 

moderately alkaline; abrupt smooth boundary. 

lIC2casim-34 inches; indurated lime- and silicacemented duripan. 

Depth to the duripan is 20 to 40 inches. The duripan is 6 

to 24 inches thick and overlies old gravelly alluvial material, 

tuffaceous sandstone, or basalt. The mollic epipedon is 7 to 

15 inches thick. The A horizon has value of 4 or 5 when dry 

and 2 or 3 when moist. The B2t horizon is heavy silt loam, 

clay loam, or silty clay loam. The B2tca horizon has value of 

5 or 6 when dry and 3 or 4 when moist, and it has chroma 

of 2 or 3 when moist or dry. It is clay loam or silty clay loam.

Shano series 

The Shano series consists of very deep, well drained soils 

on uplands. These soils formed in loess. Slopes range from 

2 to 30 percent. Elevation is 650 to 1,200 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 170 days. 

Typical pedon of Shano silt loam, 8 to 15 percent 

slopes, about 5 miles southwest of Mabton, about 1,800 

feet north and 130 feet west of the southeast corner of sec. 

27, T. 8 N., R. 22 E. 

A1-0 to 4 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; moderate thin platy 

structure; soft, friable, nonsticky and nonplastic; 

many very fine and common fine roots; mildly 

alkaline; abrupt smooth boundary. 
B2-4 to 20 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; weak medium prismatic 

structure parting to weak medium angular blocky; 

soft, friable, slightly sticky and slightly plastic; common 

very fine and fine roots and few medium roots; very fine 

tubular pores; mildly alkaline; gradual smooth boundary. 

B3-20 to 30 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; soft, friable, slightly 

sticky and slightly plastic; common very fine roots; few 

very fine tubular pores; mildly alkaline; abrupt smooth 

boundary. 

C2ca-30 to 43 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; massive; slightly hard, firm, 

slightly sticky and slightly plastic; few fine and common 

very fine roots; few very fine tubular pores; segregated 

lime in root channels; slightly effervescent; strongly 

alkaline; clear wavy boundary. 

C3-43 to 60 inches; pale brown (10YR 6/3) silt loam, 

grayish brown (10YR 5/2) moist; massive; slightly hard, 

firm, slightly sticky and slightly plastic; few very fine 

roots; few very fine tubular pores; strongly effervescent; 

strongly alkaline. 

Depth to secondary carbonates is 24 to 40 inches. The A 

horizon has value of 5 or 6 when dry and 3 or 4 when moist, 

and it has chroma of 2 or 3 when dry or moist. It is neutral to 

moderately alkaline. The B horizon has value of 5 or 6 when 

dry and 3 or 4 when moist, and it has chroma of 2 or 3 when 

dry or moist. It is mildly alkaline or moderately alkaline. 

The C horizon has value of 6 or 7 when dry. 

Simcoe series 

The Simcoe series consists of moderately deep, well 

drained soils on uplands. These soils formed in loess and in 

residuum derived from basalt and contain a small amount of 

volcanic ash. Slopes range from 5 to 30 percent. Elevation 

is 1,200 to 2,300 feet. The average annual precipitation is 

10 to 12 inches, the average annual air temperature is 

about 50 degrees F, and the average frost-free season is 

120 to 170 days. 

Typical pedon of a Simcoe silt loam (5 to 15 percent 

slopes), in an area of Rock Creek-Clint-Simcoe 

complex, 0 to 45 percent slopes, about 4 miles west of 

Fruitvale, about 1,620 feet south and 2,340 feet west of the 

northeast corner of sec. 13, T. 13 N., R. 17 E. 

A1-0 to 3 inches; brown (7.5YR 4/4) silt loam, dark brown 

(7.5YR 3/2) moist; moderate fine granular structure; soft, 

very friable, slightly sticky and slightly plastic; many 

fine roots; many very fine tubular pores; 10 

percent pebbles; neutral; clear wavy boundary. 

B1-3 to 14 inches; brown (7.5YR 4/4) silt loam, dark 

brown (7.5YR 3/2) moist; moderate medium 

subangular blocky structure; soft, friable, slightly sticky 

and plastic; common fine roots; many very fine tubular 

pores; 5 percent pebbles; neutral; clear wavy boundary.

B22t-14 to 27 inches; brown (7.5YR 4/4) heavy silt loam, 

dark brown (7.5YR 3/2) moist; strong medium angular 

blocky structure; slightly hard, firm, sticky and plastic; 

common fine roots; common very fine vesicular pores; 

common thin clay films on faces of peds; 10 percent 

pebbles; mildly alkaline; abrupt wavy boundary. 

R-27 inches; basalt. 

Depth to basalt is 20 to 40 inches. The mollic epipedon is 

10 to 20 inches thick. The A horizon has hue of 10YR or 

7.5YR, and it has value of 4 or 5 when dry and 2 or 3 when 

moist. The B2t horizon has hue of 10YR or 7.5YR, and it 

has value of 4 to 6 when dry and 3 or 4 when moist. It is 

heavy silt loam, silty clay loam, or clay loam and is 0 to 15 

percent coarse fragments. 

Sinloc series 

The Sinloc series consists of very deep, somewhat poorly 

drained soils on terraces. These soils formed in lacustrine 

sediment that has a mantle of loess. Slopes range from 0 to 

8 percent. Elevation is 650 to 1,200 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 135 to 180 days. 

Typical pedon of Sinloc silt loam, 2 to 5 percent slopes, 

about 3 miles west of Outlook, about 1,600 feet north and 

340 feet west of the southeast corner of sec. 24, T. 10 N., R. 

21 E. 

A11-0 to 1/2 inch; dark grayish brown (10YR 4/2) silt loam, 

light brownish gray (10YR 6/2) dry; weak very fine granular 

structure; soft, very friable, nonsticky and slightly plastic; 

many very fine roots; salt incrustations on the surface 

and on faces of peds; violently effervescent; strongly 

alkaline; abrupt smooth boundary. 

A12-1/2 inch to 3 inches; dark grayish brown (10YR 4/2) 

silt loam, light brownish gray (10YR 6/2) dry; weak 

fine granular structure; soft, very friable, nonsticky and 

slightly plastic; many very fine roots; violently 

effervescent; strongly alkaline; abrupt smooth 

boundary. 

B2-3 to 15 inches; dark grayish brown (10YR 4/2) silt 

loam, light brownish gray (10YR 6/2) dry; weak 

medium subangular blocky structure; slightly hard, 

friable, nonsticky and slightly plastic; common very fine 

roots; violently effervescent; strongly alkaline; abrupt 

smooth boundary. 
C1ca-15 to 31 inches; dark grayish brown (2.5Y 4/2) silt 

loam, light brownish gray (2.5YR 6/2) dry; massive; 

hard, firm, slightly sticky and slightly plastic; few very 

fine roots; threadlike veins of lime; violently 

effervescent; strongly alkaline; abrupt wavy boundary. 

C2-31 to 35 inches; dark grayish brown (2.5Y 4/2) fine 

sandy loam, light brownish gray (2.5Y 6/2) dry; 

massive; soft, friable, nonsticky and nonplastic; 

common very fine roots; violently effervescent; strongly 

alkaline; abrupt wavy boundary. 

C3-35 to 45 inches; dark grayish brown (2.5Y 4/2) silt 

loam, light brownish gray (2.5Y 6/2) dry; massive; 

slightly hard, friable, nonsticky and slightly plastic; few 

very fine roots; violently effervescent; moderately 

alkaline; abrupt wavy boundary. 

C4-45 to 60 inches; dark grayish brown (2.5Y 4/2) loamy 

fine sand, light brownish gray (2.5Y 6/2) dry; massive; 

soft, very friable, nonsticky and nonplastic; few very 

fine roots; thin lenses of silt loam; slightly effervescent; 

moderately alkaline. 

The profile is moderately alkaline or strongly alkaline. 

The solum is 15 to 30 inches thick. 

The A horizon has value of 3 or 4 when moist and 5 or 6 

when dry. It is silt loam or fine sandy loam. 

The B horizon has value of 3 or 4 when moist and 5 or 6 

when dry. It is silt loam or very fine sandy loam. 

The C horizon has value of 4 or 5 when moist, and it has 

chroma of 1 or 2 when dry or moist. Between depths of 15 

and 40 inches the C horizon is silt loam or very fine sandy 

loam, is less than 15 percent sand that is fine or coarse, and 

is less than 18 percent clay. Below a depth of 40 inches it is 

silt loam, sandy loam, or loamy fine sand. 

Starbuck series 

The Starbuck series consists of shallow, well drained 

soils on uplands. These soils formed in loess overlying 

basalt. Slopes range from 0 to 60 percent. Elevation is 700 

to 2,000 feet. The average annual precipitation is 6 to 10 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 135 to 170 

days. 

Typical pedon of Starbuck silt loam, 2 to 15 percent 

slopes, about 1/2 mile north of Byron, about 2,800 feet 

east and 3,500 feet south of the northwest corner of sec. 

12, T. 8 N., R. 23 E. 

A11-0 to 3 inches; brown (10YR 5/3) silt loam, dark brown 

(10YR 3/3) moist; weak thin platy structure; soft, very 

friable, nonsticky and slightly plastic; many fine roots; 

many very fine tubular pores; neutral; clear smooth 

boundary. 

A12-3 to 6 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak medium platy 

structure; soft, very friable, nonsticky and slightly 

plastic; common very fine roots; many very fine 

tubular pores; neutral; clear wavy boundary. 

B21-6 to 9 inches; pale brown (10YR 6/3) silt loam, dark 

brown (10YR 3/3) moist; moderate fine subangular 

blocky structure; slightly hard, friable, slightly 

sticky and slightly plastic; common very fine roots; 

many very fine tubular pores; 10 percent pebbles; 

neutral; clear smooth boundary. 

B22-9 to 16 inches; pale brown (10 Y R 6/3) gravelly silt 

loam, dark brown (10YR 3/3) moist; weak medium 

prismatic structure; soft, very friable, slightly sticky and 

slightly plastic; common very fine roots; many very fine 

tubular pores; 20 percent pebbles; neutral; abrupt 

smooth boundary. 

R-16 inches; basalt. 

Depth to basalt is 12 to 20 inches. The control section is 

5 to 25 percent coarse fragments. The profile is neutral or 

mildly alkaline. The A horizon has value of 5 or 6 when dry 

and 3 or 4 when moist, and it has chroma of 3 or 4 when 

moist. The B2 horizon has value of 5 or 6 when dry, and it 

has chroma of 3 or 4 when dry or moist. It is gravelly silt 

loam, loam, or fine sandy loam. 

Sutkin series 

The Sutkin series consists of very deep, well drained 

soils on mountainsides, on smooth mountaintops, and in 

canyons. These soils formed in colluvium and residuum 

derived dominantly from basalt and containing a small 

amount of loess. Slopes range from 0 to 65 percent. 

Elevation is 2,400 to 4,800 feet. The average annual 

precipitation is 18 to 22 inches, the average annual air 

temperature is about 43 degrees F, and the average length 

of the growing season, at 28 degrees F, is 145 to 170 days. 

Typical pedon of Sutkin stony loam, 0 to 25 percent 

slopes, about 6 miles west of Tampico, about 1,100 feet 

west and 2,300 feet south of the northeast corner of sec. 

14, T. 12 N., R. 14 E. 

O1&O2-1/2 inch to 0; decomposing forest litter. 

A1-0 to 10 inches; dark brown (10YR 3/3) stony loam, 

very dark brown (10YR 2/2) moist; weak fine granular 

structure; soft, very friable, nonsticky and slightly plastic; 

many fine and common coarse roots; 5 percent stones; 

slightly acid; clear wavy boundary. 

B1-10 to 20 inches; dark yellowish brown (10YR 4/4) 

very cobbly loam, dark brown (7.5YR 3/2) moist; weak 

medium subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; common 

coarse and many fine roots; 30 percent pebbles and 

20 percent cobbles; neutral; clear irregular boundary. 
B2-20 to 38 inches; dark yellowish brown (10YR 4/4) 

extremely cobbly loam, dark brown (7.5YR 3/4) 

moist; moderate medium subangular blocky 

structure; slightly hard, friable, slightly sticky and 

plastic; common coarse and many fine roots; 35 

percent pebbles and 35 percent cobbles; neutral; 

clear wavy boundary. 

C-38 to 60 inches; dark yellowish brown (10YR 4/4) 

extremely cobbly loam, dark yellowish brown 

(10YR 3/4) moist; massive; slightly hard, friable, 

slightly sticky and plastic; common fine and coarse 

roots; 30 percent pebbles and 40 percent cobbles; 

neutral. 

The mollic epipedon is 10 to 18 inches thick. The 

control section averages 40 to 60 percent rock 

fragments and 18 to 30 percent clay. 

The A horizon has value of 3 or 4 when dry and 2 or 3 

when moist, and it has chroma of 3 or 4 when dry and 1 to 

3 when moist. 

The B2 horizon has value of 4 to 6 when dry, and it has 

chroma of 3 or 4 when moist. It is extremely cobbly loam, 

very gravelly loam, or very cobbly loam. 

The C horizon has value of 3 or 4 when moist, and it has 

chroma of 3 or 4 when moist. It is extremely cobbly loam or 

very cobbly clay loam. 

Sutkin Variant 

The Sutkin Variant consists of very deep, well drained 

soils on alluvial fans. These soils formed in loess overlying 

cobbly or gravelly alluvium. Slopes range from 0 to 5 

percent. Elevation is 2,400 to 2,600 feet. The average 

annual precipitation is 14 to 17 inches, the average annual 

air temperature is about 48 degrees F, and the average 

length of the growing season, at 28 degrees F, is 150 to 

170 days. 

Typical pedon of Sutkin Variant stony loam, 0 to 5 

percent slopes, about 12 miles northwest of Naches, 

about 750 feet west and 40 feet north of the southeast 

corner of sec. 15, T. 16 N., R. 16 E. 

O1-1/2 inch to 0; decomposing forest litter. 

A1-0 to 8 inches; grayish brown (10YR 5/2) stony 

loam, very dark grayish brown (10YR 3/2) moist; 

moderate thin platy structure; soft, very friable, 

nonsticky and nonplastic; many fine roots and 

common coarse roots; 5 percent stones; neutral; 

clear wavy boundary. 

B1-8 to 14 inches; brown (10YR 5/3) gravelly loam, dark 

brown (10YR 3/3) moist; weak fine subangular blocky 

structure; slightly hard, friable, nonsticky and 

nonplastic; many fine roots and common coarse roots; 

20 percent pebbles; neutral; clear wavy boundary. 

B2-14 to 18 inches; pale brown (10YR 6/3) very 

gravelly loam, brown (10YR 4/3) moist; moderate 

medium subangular blocky structure; slightly 

hard, friable, slightly sticky and slightly plastic; many 

fine roots and common coarse roots; 40 percent 

pebbles; neutral; clear wavy boundary. 

C-18 to 60 inches; pale brown (10YR 6/3) extremely 

gravelly sandy loam, brown (10YR 4/3) moist; massive; 

soft, very friable, nonsticky and nonplastic; few fine roots 

and common coarse roots; 70 percent pebbles; neutral. 

The mollic epipedon is 10 to 16 inches thick. The 

control section averages 40 to 60 percent coarse 

fragments. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 1 to 3 when moist.

The B2 horizon has chroma of 3 or 4 when dry or 

moist. It is very cobbly loam or very gravelly loam. 

The C horizon has value of 4 to 6 when dry and 3 or 4 

when moist, and it has chroma of 3 or 4 when moist. It is 

very gravelly sandy loam or extremely gravelly sandy loam. 

Taneum series 

The Taneum series consists of very deep, well drained 

soils on uplands. These soils formed in loess overlying 

material weathered from sandstone. Slopes range from 5 to 

60 percent. Elevation is 2,300 to 3,000 feet. The average 

annual precipitation is 15 to 18 inches, the average annual 

air temperature is about 48 degrees F, and the average frostfree season is 120 to 135 days. 

Typical pedon of Taneum loam, 5 to 15 percent slopes, 

about 6 miles west of Cowiche, about 2,000 feet west and 

20 feet south of the northeast corner of sec. 29, T. 14 N., R. 

16 E. 

A11-0 to 4 inches; dark grayish brown (10YR 4/2) loam, 

very dark brown (10YR 2/2) moist; weak fine granular 

structure; soft, very friable, nonsticky and slightly 

plastic; many very fine roots; neutral; abrupt wavy 

boundary. 

A12-4 to 10 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; moderate medium 

granular structure; slightly hard, friable, slightly sticky and 

slightly plastic; common very fine roots; neutral; 

abrupt wavy boundary. 

A3-10 to 14 inches; grayish brown (19YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; moderate 

medium subangular blocky structure; slightly 

hard, friable, slightly sticky and slightly plastic; common 

very fine roots; neutral; clear wavy boundary. 
B22t-14 to 27 inches; brown (7.5YR 5/4) silty clay 

loam, dark brown (7.5YR 3/4) moist; moderate 

medium subangular blocky structure; hard, 

firm, sticky and plastic; few very fine roots; few 

fine tubular pores; thin patchy clay films on faces of 

peds; neutral; clear wavy boundary. 

B23t-27 to 43 inches; brown (7.5YR 5/4) clay loam, 

dark brown (7.5YR 3/4) moist; weak medium 

subangular blocky structure; hard, firm, sticky and 

plastic; few very fine roots; few fine tubular pores; 

thin patchy clay films on faces of peds; neutral; clear 

wavy boundary. 

C1-43 to 50 inches; yellowish brown (10YR 5/4) loam, 

dark yellowish brown (10YR 3/4) moist; massive; 

slightly hard, friable, nonsticky and slightly plastic; few 

very fine roots; common fine tubular pores; neutral; 

abrupt wavy boundary. 

C2-50 to 60 inches; brown (10YR 5/3) sandy loam, dark 

brown (10YR 3/3) moist; massive; hard, friable, 

nonsticky and nonplastic; common fine tubular pores; 

neutral. 

The mollic epipedon is 12 to 19 inches thick. The control 

section is 27 to 35 percent clay, is more than 15 percent 

sand that is fine or coarser, and is less than 15 percent rock 

fragments. The B horizon has hue of 10YR or 7.5YR. 

Tekison series 

The Tekison series consists of very deep, well drained 

soils on mountainsides, mountain ridges and benches, and 

smooth mountaintops. These soils formed in residuum and 

colluvium derived from basalt and containing a small amount 

of loess. Slopes range from 0 to 25 percent. Elevation is 

2,800 to 3,600 feet. The average annual precipitation is 16 

to 20 inches, the average annual air temperature is about 47 

degrees F, and the average length of the growing season, at 

28 degrees F, is 150 to 170 days. 

Typical pedon of Tekison stony loam, 0 to 25 percent 

slopes, about 5 miles northwest of Tampico, about 150 feet 

east and 900 feet north of the southwest corner of sec. 27, 

T. 13 N., R. 15 E. 

A1-0 to 4 inches; brown (10YR 4/3) stony loam, very 

dark grayish brown (10YR 3/2) moist; moderate 

medium subangular blocky structure; slightly hard, 

friable, slightly sticky and plastic; common very fine 

roots; few fine and many very fine tubular pores; 5 

percent stones; neutral; abrupt smooth boundary. 

B1-4 to 12 inches; brown (10YR 4/3) stony loam, dark 

brown (10YR 3/3) moist; moderate fine subangular 

blocky structure; hard, firm, slightly sticky and plastic; 

common fine roots; few fine and many very fine tubular 

pores; 10 percent stones and 15 percent pebbles; 

slightly acid; clear smooth boundary. 

B21t-12 to 20 inches; brown (10YR 5/3) very cobbly clay 

loam, dark brown (10YR 3/3) moist; moderate medium 

angular blocky structure; hard, very firm, sticky and 

very plastic; few fine and medium roots; common very 

fine tubular pores; common moderately thick clay films 

on faces of peds; 20 percent pebbles and 20 percent 

cobbles; slightly acid; gradual wavy boundary. 

B22t-20 to 31 inches; yellowish brown (10YR 5/4) very 

gravelly clay, dark yellowish brown (10YR 4/4) moist; 

moderate medium angular blocky structure; hard, very 

firm, very sticky and very,

 plastic; ; few very fine roots; 

common very fine tubular pores; many thick clay films 

on faces of peds; 30 percent pebbles and 10 percent 

cobbles; slightly acid; gradual wavy boundary. 

B23t-31 to 60 inches; brown (10YR 5/3) very cobbly clay, 

dark brown (10YR 3/3) moist; strong fine and medium 

angular blocky structure; extremely hard, extremely firm, 

very sticky and very plastic; few very fine roots; 

common very fine tubular pores; continuous thick clay 

films on faces of peds; 25 percent pebbles and 15 

percent cobbles; slightly acid. 

The mollic epipedon is 10 to 18 inches thick. The control 

section is 40 to 50 percent rock fragments. The A horizon 

has value of 4 or 5 when dry, and it has chroma of 2 or 3 

when moist. The B2t horizon has chroma of 2 to 4 when dry 

or moist. It is very cobbly clay loam, very gravelly clay, or 

very cobbly clay. 

Tieton series 

The Tieton series consists of deep, well drained soils on 

uplands. These soils formed in loess and in material 

weathered from andesite. Slopes range from 0 to 30 

percent. Elevation is 1,500 to 2,300 feet. The average 

annual precipitation is 11 to 15 inches, the average annual 

air temperature is about 50 degrees F, and the average 

frost-free season is 135 to 150 days. 

Typical pedon of Tieton loam, 2 to 5 percent slopes, 

about 1 mile northeast of Cowiche, about 1,300 feet south 

and 900 feet east of the northwest corner of sec. 22, T. 14 

N., R. 17 E. 

Ap-0 to 3 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; weak fine 

granular structure; soft, very friable, slightly sticky and 

slightly plastic; many very fine roots; neutral; abrupt 

smooth boundary. 

A12-3 to 9 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; weak medium 

granular structure; soft, very friable, slightly sticky and 

slightly plastic; common very fine roots; few fine tubular 

pores; neutral; clear wavy boundary. 
B1-9 to 15 inches; brown (10YR 5/3) loam, dark brown 

(10YR 3/3) moist; weak medium subangular blocky 

structure; slightly hard, friable, slightly sticky and slightly 

plastic; common very fine roots; few fine tubular 

pores; neutral; clear wavy boundary. 

B21t-15 to 31 inches; yellowish brown (10YR 5/4) silty 

clay loam, dark yellowish brown (10YR 3/4) moist; 

moderate medium subangular blocky structure; hard, 

firm, slightly sticky and plastic; few fine roots; few fine 

tubular pores; siliceous coatings on faces of peds; 

neutral; clear wavy boundary. 

B22t-31 to 37 inches; yellowish brown (10YR 5/4) clay 

loam, dark yellowish brown (10YR 3/4) moist; weak 

medium subangular blocky structure; hard, firm, slightly 

sticky and plastic; few fine roots; few fine tubular pores; 

neutral; abrupt smooth boundary. 

B23t-37 to 44 inches; brown (10YR 5/3) clay loam, dark 

yellowish brown (10YR 3/4) moist; moderate fine 

subangular blocky structure; hard, firm, sticky and 

plastic; few fine roots; few fine tubular pores; thin 

discontinuous clay films on faces of peds and in pores; 

neutral; clear wavy boundary. 

C1-44 to 48 inches; grayish brown (10YR 5/2) loam, dark 

grayish brown (10YR 4/2) moist; massive; hard, firm, 

slightly sticky and slightly plastic; few fine roots; many 

very fine tubular pores; 5 percent fragments of 

andesite; lime coatings on upper boundary; neutral; 

abrupt smooth boundary. 

Crca-48 to 50 inches; light yellowish brown (2.5Y 6/4) 

weathered andesite, olive brown (2.5Y 4/4) moist; 

massive; hard, firm; lime coatings on upper 

boundary; neutral; abrupt smooth boundary. 

IIR-50 inches; andesite. 

The mollic epipedon is 10 to 16 inches thick. The control 

section is 27 to 35 percent clay. Depth to weathered 

andesite ranges from 40 to 60 inches. The A horizon has 

value of 4 or 5 when dry and 2 or 3 when moist. It is loam 

or fine sandy loam. The B horizon has value of 4 to 6 when 

dry and 3 or 4 when moist. The C horizon has hue of 10YR 

or 2.5Y, value of 5 or 6 when dry and 3 or 4 when moist, 

and chroma of 3 or 4 when dry or moist. It is loam or clay 

loam. 

Toppenish series 

The Toppenish series consists of very deep, somewhat 

poorly drained soils on flood plains. These soils formed in 

alluvium. Slopes range from 0 to 2 percent. Elevation is 

700 to 1,800 feet. The average annual precipitation is 8 to 

10 inches, the average annual air temperature is about 51 

degrees F, and the average frost-free season is 130 to 

180 days. 

Typical pedon of Toppenish silt loam, about 3 miles 

southeast of Yakima, about 1,400 feet east and 2,600 feet 

south of the northwest corner of sec. 33, T. 13 N., 

R.19E. 

Ap-0 to 4 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; moderate 

thin platy structure; soft, very friable, slightly sticky and 

slightly plastic; many fine and common medium roots; 

common very fine vesicular pores; violently 

effervescent; strongly alkaline; abrupt smooth 

boundary. 

B1-4 to 14 inches; gray (10YR 5/1) silty clay loam, black 

(10YR 2/1) moist; moderate medium angular blocky 

structure; slightly hard, friable, sticky and plastic; 

common fine and few medium roots; common very fine 

vesicular pores; violently effervescent; strongly alkaline; 

clear wavy boundary. 

IIB21g-14 to 35 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark grayish brown (10YR 3/2) moist; 

common medium distinct mottles that are yellowish 

brown (10YR 5/6) when moist; slightly hard, friable, 

slightly sticky and slightly plastic; common fine and few 

medium roots; common very fine vesicular pores and 

few fine tubular pores; moderately alkaline; gradual wavy 

boundary. 

IIIB22-35 to 50 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; many medium distinct mottles 

that are yellowish brown (10YR 5/6) when moist; weak 

medium subangular blocky structure; slightly hard, 

friable, slightly sticky and plastic; common fine and few 

medium roots; common very fine vesicular pores; 5 

percent pebbles; mildly alkaline; clear smooth boundary. 

IVC1-50 to 60 inches; brown (10YR 5/3) extremely 

gravelly sand, very dark grayish brown (10YR 3/2) 

moist; massive; loose; few very fine and medium 

roots; 60 percent pebbles; mildly alkaline. 

The mollic epipedon is 10 to 20 inches thick. The IVC 

horizon is at a depth of 40 inches or more. The profile is 

mildly alkaline to strongly alkaline. 

The A and B1 horizons have value of 2 or 3 when 

moist. 

The B2g horizon has value of 4 or 5 when dry and 3 or 4 

when moist, and it has chroma of 1 or 2 when dry or moist. 

It has distinct or prominent mottles. This horizon is silt 

loam, loam, or clay loam and averages 20 to 30 percent 

clay. 

The C horizon has hue of 10YR or 2.5Y, value of 4 to 6 

when dry, and chroma of 2 to 4 when dry or moist. It is 

extremely gravelly sandy loam or extremely gravelly 

sand. 

Track series 

The Track series consists of very deep, somewhat poorly 

drained soils on flood plains. These soils formed in mixed 

alluvium. Slopes range from 0 to 2 percent. Elevation is 

800 to 1,500 feet. The average annual precipitation is 8 to 

10 inches, the average annual air 
temperature is about 51 degrees F, and the average 

frost-free season is 130 to 180 days. 

Typical pedon of Track loam, about 1 mile east of Union 

Gap, about 1,500 feet west and 100 feet south of the 

northeast corner of sec. 4, T. 12 N., R. 19 E. 

A11-0 to 14 inches; dark grayish brown (10YR 4/2) loam, 

very dark brown (10YR 2/2) moist; moderate medium 

granular structure; slightly hard, friable, slightly sticky 

and slightly plastic; many very fine roots; common very 

fine pores; 0 to 5 percent pebbles; disseminated 

carbonates; violently effervescent; strongly alkaline; 

abrupt smooth boundary. 

IIB21g-14 to 21 inches; grayish brown (10YR 5/2) very 

gravelly loam, very dark grayish brown (10YR 3/2) 

moist; few fine distinct yellowish brown (10YR 5/6) 

mottles; weak fine granular structure; slightly hard, 

friable, slightly sticky and slightly plastic; common very 

fine roots; common very fine pores; 50 percent pebbles 

and 10 percent cobbles; disseminated carbonates and 

filaments of segregated carbonates; violently 

effervescent; strongly alkaline; abrupt wavy 

boundary. 

IIB22-21 to 26 inches; brown (10YR 5/3) very gravelly 

loam, very dark grayish brown (10YR 3/2) moist; 

common fine distinct yellowish brown (10YR 5/6) 

mottles; weak fine subangular blocky structure; 

slightly hard, friable, slightly sticky and slightly 

plastic; few very fine roots; few very fine pores; 40 

percent pebbles and 10 percent cobbles; moderately 

alkaline; abrupt wavy boundary. 

IIC1-26 to 60 inches; brown (10YR 5/3) very gravelly 

loamy sand, dark brown (10YR 3/3) moist; many fine 

distinct yellowish brown (10YR 5/6) mottles; 

massive; slightly hard, very friable, nonsticky 

and nonplastic; 40 percent pebbles and 10 percent 

cobbles; moderately alkaline. 

The control section averages 45 to 65 percent coarse 

fragments. The mollic epipedon is 10 to 20 inches thick. The 

IIC horizon is at a depth of 20 to 30 inches. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 1 or 2 when dry or moist. 

It is mildly alkaline to strongly alkaline. 

The IIB horizon has value of 4 or 5 when dry and 2 or 3 

when moist. It is moderately alkaline or strongly alkaline. 

The C horizon has value of 4 or 5 when dry and 3 or 4 

when moist, and it has chroma of 1 to 3 when dry or moist. 

It has distinct or prominent mottles. The horizon is very 

gravelly sand or very gravelly loamy sand and is moderately 

alkaline or strongly alkaline. 

Tumac series 

The Tumac series consists of very deep, well drained soils 

on south-facing uplands and mountainsides. These soils 

formed in colluvium derived from basalt and andesite and 

containing volcanic ash. Slopes range from 5 to 45 percent. 

Elevation is 4,100 to 5,200 feet. The average annual 

precipitation is 30 to 60 inches, the average annual air 

temperature is about 43 degrees F, and the average length 

of the growing season, at 28 degrees F, is 145 to 170 days.

Typical pedon of Tumac very stony sandy loam, 5 to 45 

percent slopes, about 20 miles west of Tampico, about 200 

feet east and 100 feet south of the northwest corner of sec. 

27, T. 12 N., R. 12 E. 

O1-2 inches to 0; decomposing forest litter. 

A11-0 to 4 inches; brown (10YR 5/3) very stony sandy 

loam, dark brown (10YR 3/3) moist; weak very fine 

granular structure; soft, very friable, nonsticky and 

nonplastic; weakly smeary; few very fine and common 

fine roots; 10 percent stones; medium acid; abrupt wavy 

boundary. 

A12-4 to 15 inches; brown (10YR 5/3) very gravelly 

loam, dark brown (10YR 3/3) moist; moderate fine 

granular structure; soft, very friable, slightly sticky and 

slightly plastic; weakly smeary; common very fine, fine, 

and medium roots; 40 percent pebbles; medium acid; 

abrupt wavy boundary. 

B21-15 to 30 inches; yellowish brown (10YR 5/4) very 

gravelly loam, dark brown (7.5YR 3/4) moist; common 

very fine subangular blocky structure; slightly hard, 

friable, slightly sticky and slightly plastic; weakly 

smeary; few very fine and common fine roots; 45 

percent pebbles and 5 percent cobbles; medium acid; 

clear wavy boundary. 

B22-30 to 50 inches; yellowish brown (10YR 5/4) 

extremely gravelly loam, dark yellowish brown 

(10YR 3/4) moist; moderate fine granular structure; 

slightly hard, friable, slightly sticky and slightly plastic; 

weakly smeary; few fine roots; 55 percent pebbles and 

10 percent cobbles; medium acid; clear wavy boundary.

B23-50 to 60 inches; strong brown (7.5YR 5/6) extremely 

gravelly loam, dark yellowish brown (10YR 3/4) moist; 

moderate very fine subangular blocky structure; slightly 

hard, friable, slightly sticky and slightly plastic; weakly 

smeary; 60 percent pebbles and 5 percent cobbles; 

medium acid. 

The control section is 35 to 70 percent rock fragments. 

The A horizon has chroma of 2 or 3 when moist. The B 

horizon has chroma of 4 to 6 when moist. It is very gravelly 

loam, extremely gravelly loam, or very cobbly sandy loam. 
Umapine series 

The Umapine series consists of very deep, somewhat 

poorly drained soils on flood plains and low terraces. These 

soils formed in alluvium. Slopes range from 0 to 5 percent. 

Elevation is 650 to 900 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 130 to 180 days. 

Typical pedon of Umapine silt loam, 0 to 5 percent 

slopes, about 3 miles northeast of Mabton, about 2,510 feet 

north and 660 feet west of the southeast corner of sec. 23, 

T. 9 N., R. 22 E. 

Ap-0 to 7 inches; light brownish gray (2.5Y 6/2) silt loam, 

very dark grayish brown (2.5Y 3/2) moist; weak medium 

subangular blocky structure; hard, friable, slightly sticky 

and plastic; common fine roots; common fine pores; 

violently effervescent; very strongly alkaline; abrupt 

smooth boundary. 

C1-7 to 16 inches; light brownish gray (2.5Y 6/2) silt loam, 

dark grayish brown (2.5Y 4/2) moist; weak medium 

angular blocky structure; hard, friable, sticky and 

plastic; common fine roots; common fine pores; 

disseminated lime; violently effervescent; very 

strongly alkaline; gradual wavy boundary. 

C2-16 to 34 inches; light brownish gray (2.5Y 6/2) silt 

loam, dark grayish brown (2.5Y 4/2) moist; weak 

medium subangular blocky structure; slightly hard, 

friable, slightly sticky and plastic; few fine roots; 

common fine pores; disseminated lime; slightly 

effervescent; very strongly alkaline; abrupt smooth 

boundary. 

IIC3-34 to 41 inches; light gray (2.5Y 7/2) silt loam, 

dark grayish brown (2.5Y 4/2) moist; massive; slightly 

hard, friable, slightly sticky and slightly plastic; few 

fine roots; common fine pores; disseminated lime; 

violently effervescent; strongly alkaline; abrupt 

smooth boundary. 

IIIC4-41 to 60 inches; light brownish gray (2.5Y 6/2) silt 

loam, dark grayish brown (2.5Y 4/2) moist; massive; 

slightly hard, friable, slightly sticky and plastic; common 

fine pores; disseminated lime; violently effervescent; 

strongly alkaline. 

In most years the profile is saturated with water to a 

depth of 40 inches at some time during the year. The 

profile has hue of 2.5Y or 10YR. The A horizon has value 

of 5 or 6 when dry and 3 to 5 when moist, and it has 

chroma of 2 or 3. The C horizon has value of 5 to 7 when 

dry and 3 to 5 when moist, and it has chroma of 1 or 2. 

Wanser series 

The Wanser series consists of very deep, poorly drained 

soils on terraces in basins. These soils formed in sand 

derived from mixed sources. Slopes range from 0 

to 5 percent. Elevation is 650 to 1,100 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air

temperature is about 50 degrees F, and the average frostfree season is 120 to 150 days. 

Typical pedon of Wanser loamy fine sand, about 2 miles 

southwest of Sunnyside, about 900 feet west and 1,100 

feet north of the southeast corner of sec. 2, T. 9 N., R. 22 

E. 

Ap-0 to 6 inches; grayish brown (10YR 5/2) loamy fine 

sand, dark grayish brown (10YR 4/2) moist; single gram 

loose; many fine roots; moderately alkaline; clear 

smooth boundary. 

C1g-6 to 18 inches; dark grayish brown (10YR 4/2) loamy 

fine sand, dark gray (5Y 4/1) moist; few fine distinct 

mottles that are yellowish brown (10YR 5/6) when 

moist; single grain; loose; many fine roots; moderately 

alkaline; abrupt wavy boundary. 

C2g-18 to 20 inches; grayish brown (10YR 5/2) loamy 

fine sand, dark bluish gray (5B 4/1) moist; common 

fine prominent mottles that are bluish gray (5B 6/1) 

when moist; massive; soft, very friable, nonsticky and 

nonplastic; few medium roots; slightly effervescent; 

strongly alkaline; clear smooth boundary. 

C3g-20 to 25 inches; grayish brown (10YR 5/2) loamy fine 

sand, bluish gray (5B 6/1) moist; single grain; loose; 

few fine roots; strongly alkaline; gradual wavy 

boundary. 

C4g-25 to 57 inches; grayish brown (10YR 5/2) loamy fine 

sand, bluish gray (5B 5/1) moist; mottles that are dark 

greenish gray (5Y 4/1) when moist; single grain; loose; 

few fine roots; strongly alkaline; gradual smooth 

boundary. 

C5g-57 to 60 inches; light brownish gray (10YR 6/2) 

fine sand, gray (N 5/0) moist; single grain; loose; 

strongly alkaline. 

Where these soils are not artificially drained, the water 

table fluctuates between the surface and a depth of 12 

inches. The profile is moderately alkaline or strongly alkaline. 

The 10- to 40-inch control section is sand to loamy fine sand. 

The A horizon has value of 5 or 6 when dry and 3 or 4 when 

moist. The Cg horizon has value of 3 to 6 when moist. 

Warden series 

The Warden series consists of very deep, well drained soils 

on terraces. These soils formed in lacustrine sediment and 

have a mantle of loess. Slopes range from 0 to 30 percent. 

Elevation is 600 to 1,000 feet. The average annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 135 to 180 days. 

Typical pedon of Warden silt loam, 8 to 15 percent slopes, 

about 4 miles south of Mabton, about 100 feet 
south and 100 feet east of the northwest corner of sec. 

26, T. 8 N., R. 22 E. 

Ap-0 to 5 inches; brown (10YR 5/3) silt loam, dark brown 

(10YR 3/3) moist; moderate medium granular structure; 

soft, very friable, slightly sticky and slightly plastic; many 

fine and very fine roots; mildly alkaline; clear smooth 

boundary. 

B2-5 to 19 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; weak medium subangular 

blocky structure; soft, friable, slightly sticky and 

slightly plastic; common fine and many very fine roots; 

many very fine pores; mildly alkaline; abrupt wavy 

boundary. 

IIC1ca-19 to 41 inches; light gray (10YR 7/2) loam, grayish 

brown (10YR 5/2) moist; massive; hard, very firm, 

nonsticky and nonplastic; few very fine roots; common 

very fine tubular pores; disseminated and segregated 

lime; violently effervescent; strongly alkaline; clear 

smooth boundary. 

IIIC2ca-41 to 60 inches; pale brown (10YR 6/3) silt loam, 

grayish brown (10YR 5/2) moist; massive; slightly 

hard, firm, slightly sticky and slightly plastic; few very 

fine roots; common very fine tubular pores; 

disseminated and segregated lime; violently 

effervescent; strongly alkaline. 

The solum is 15 to 30 inches thick. Depth to secondary 

lime is 15 to 30 inches. The Ap horizon has value of 5 or 6 

when dry and 3 or 4 when moist, and it has chroma of 2 or 

3 when dry or moist. It is silt loam or very fine sandy loam 

and is neutral or mildly alkaline. The B horizon is very fine 

sandy loam or silt loam and is neutral or mildly alkaline. The 

C horizon has value of 4 or 5 when moist. It is stratified silt 

loam, loam, and very fine sandy loam, but the 10- to 40-

inch control section averages less than 15 percent sand 

that is fine or coarser. 

Weirman series 

The Weirman series consists of very deep, somewhat 

excessively drained soils on low terraces and flood plains. 

These soils formed in mixed alluvium. Slopes range from 0 to 

5 percent. Elevation is 700 to 1,700 feet. The average 

annual precipitation is 7 to 14 inches, the average annual air 

temperature is about 51 degrees F, and the average frostfree season is 130 to 180 days. 

Typical pedon of Weirman sandy loam, channeled, about 

3 miles northwest of Buena, about 660 feet south and 220 

feet east of the northwest corner of sec. 7, T. 11 N., R. 20 

E. 

Ap-0 to 8 inches; grayish brown (10YR 5/2) sandy loam, 

very dark grayish brown (10YR 3/2) moist; weak fine 

granular structure; soft, friable, nonsticky and 

nonplastic; common fine roots; mildly alkaline; abrupt 

smooth boundary. 

AC-8 to 15 inches; grayish brown (10YR 5/2) loamy fine 

sand, very dark grayish brown (10YR 3/2) moist; single 

grain; loose; few very fine roots; mildly alkaline; abrupt 

smooth boundary. 

C1-15 to 21 inches; light brownish gray (10YR 6/2) loamy 

fine sand, dark grayish brown (10YR 4/2) moist; few 

medium faint dark yellowish brown (10YR 4/4) mottles; 

massive; soft, very friable, nonsticky and slightly 

plastic; few very fine roots; mildly alkaline; gradual wavy 

boundary. 

IIC2-21 to 60 inches; grayish brown (10YR 5/2) extremely 

gravelly sand, very dark grayish brown (10YR 3/2) 

moist; single grain; loose; 75 percent pebbles and 5 

percent cobbles; few very fine roots; mildly alkaline. 

The profile is neutral or mildly alkaline. The control 

section averages 35 to 60 percent coarse fragments. 

The mollic epipedon is 10 to 17 inches thick. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 2 or 3 when dry or moist. It 

is fine sandy loam, sandy loam, or gravelly fine sandy loam. 

The C horizon has value of 4 or 5 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when moist. It is 

loamy fine sand, sand, or loamy sand and in places has 

strata of sandy loam. The IIC horizon is extremely gravelly 

sand, very gravelly sand, or very gravelly loamy sand. 

Wenas series 

The Wenas series consists of very deep, somewhat poorly 

drained soils on flood plains. These soils formed in alluvium. 

Slopes range from 0 to 2 percent. Elevation is 1,100 to 

1,800 feet. The average annual precipitation is 8 to 12 

inches, the average annual air temperature is about 50 

degrees F, and the average frost-free season is 130 to 180 

days. 

Typical pedon of Wenas silt loam, about 4 miles north of 

Selah, about 400 feet east and 700 feet north of the 

southwest corner of sec. 12, T. 14 N., R. 18 E. 

Ap-0 to 8 inches; dark gray (10YR 4/1) silt loam, black 

(10YR 2/1) moist; moderate coarse granular structure; 

hard, firm, sticky and plastic; many fine roots; common 

fine pores; mildly alkaline; abrupt smooth boundary. 

B1-8 to 28 inches; dark grayish brown (10YR 4/2) silt 

loam, very dark brown (10YR 2/2) moist; moderate 

medium and fine prismatic structure; hard, firm, sticky 

and plastic; common fine roots; many fine pores; mildly 

alkaline; gradual wavy boundary. 
B2g-28 to 37 inches; gray (10YR 5/1) silty clay loam, very 

dark gray (10YR 3/1) moist; few fine distinct light 

yellowish brown (10YR 6/4) mottles; moderate 

subangular blocky structure; hard, firm, sticky and 

plastic; common fine roots; many fine pores; neutral; 

gradual wavy boundary. 

C1g-37 to 47 inches; grayish brown (10YR 5/2) loam, very 

dark grayish brown (10YR 3/2) moist; common medium 

prominent brownish yellow (10YR 6/6) mottles; 

massive; hard, friable, slightly sticky and slightly plastic; 

common fine roots; common medium pores; neutral; 

clear wavy boundary. 

IIC2g-47 to 55 inches; light brownish gray (2.5Y 6/2) 

loamy sand, dark grayish brown (2.5Y 4/2) moist; many 

medium prominent reddish yellow (7.5YR 7/8) mottles; 

massive; slightly hard, friable, nonsticky and nonplastic; 

few very fine roots; 5 'percent pebbles; mildly alkaline; 

abrupt smooth boundary. 

IIC3g-55 to 60 inches; light brownish gray (2.5Y 6/2) 

gravelly loamy sand, dark grayish brown (2.5Y 4/2) 

moist; few fine faint olive yellow (2.5Y 6/6) mottles; 

massive; slightly hard, very friable, nonsticky and 

nonplastic; 20 percent pebbles; mildly alkaline. 

The mollic epipedon is 24 to 35 inches thick. The profile is 

neutral or mildly alkaline. The control section is 0 to 15 

percent rock fragments. 

The A and B1 horizons have value of 4 or 5 when dry 

and 2 or 3 when moist. The B1 horizon is silt loam or 

clay loam. 

The B2g horizon has value of 5 or 6 when dry and 3 

or 4 when moist, and it has chroma of 1 or 2 when moist or 

dry. It is clay loam or silty clay loam. 

The Cg horizon has hue of 10YR or 2.5Y, value of 5 or 6 

when dry and 3 or 4 when moist, and chroma of 1 or 2. It is 

loam or sandy loam. 

The IICg horizon has hue of 10YR or 2.5Y, value of 5 or 6 

when dry and 3 or 4 when moist, and chroma of 1 or 2 when 

moist or dry. 

Wiehl series 

The Wiehl series consists of moderately deep, well drained 

soils on uplands. These soils formed in loess overlying 

laminated sediment and soft sandstone. Slopes range from 2 

to 60 percent. Elevation is 1,000 to 1,200 feet. The annual 

precipitation is 6 to 9 inches, the average annual air 

temperature is about 50 degrees F, and the average frostfree season is 160 to 180 days. 

Typical pedon of a Wiehl silt loam, in an area of HarwoodBurke-Wiehl silt loams, 8 to 15 percent slopes, about 3 miles 

north of Buena, about 1,620 feet south and 2,340 feet west 

of the northeast corner of sec. 13, T. 13 N., R. 17 E. 

A1-0 to 3 inches; grayish brown (10YR 5/2) silt loam, 

very dark grayish brown (10YR 3/2) moist; weak fine 

granular structure; soft, friable, slightly sticky and slightly 

plastic; many fine roots; common fine pores; neutral; 

abrupt smooth boundary. 

B21-3 to 12 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak coarse prismatic 

structure; soft, friable, slightly sticky and slightly 

plastic; common fine roots; common fine pores; 

neutral; gradual wavy boundary. 

B22-12 to 21 inches; pale brown (10YR 6/3) silt loam, 

brown (10YR 4/3) moist; weak medium subangular 

blocky structure; slightly hard, friable, slightly sticky and 

slightly plastic; few fine roots; common fine pores; 

mildly alkaline; abrupt wavy boundary. 

C1-21 to 27 inches; pale brown (10YR 6/3) gravelly silt 

loam, brown (10YR 4/3) moist; massive; slightly hard, 

friable, slightly sticky and slightly plastic; few fine roots 

matted around pebbles; common fine pores; 20 percent 

pebbles; violently effervescent; moderately alkaline; 

abrupt wavy boundary. 

IIC2r-27 inches; weathered sandstone. 

Depth to the paralithic contact ranges from 20 to 40 

inches. 

The A horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when dry or moist. It 

is silt loam or very stony silt loam and is neutral or mildly 

alkaline. 

The B horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 2 or 3 when dry or moist. It 

is fine sandy loam, very fine sandy loam, or silt loam. 

The C horizon has value of 6 or 7 when dry and 4 or 5 

when moist, and it has chroma of 2 or 3 when dry or moist. It 

is very fine sandy loam, fine sandy loam, or gravelly silt loam.

Willis series 

The Willis series consists of moderately deep, well 

drained soils on uplands. These soils formed in loess. 

Slopes range from 0 to 15 percent. Elevation is 1,200 to 

2,500 feet. The average annual precipitation is 9 to 12 

inches, the average annual air temperature is about 49 

degrees F, and the average frost-free season is 125 to 160 

days. 

Typical pedon of Willis silt loam, 8 to 15 percent slopes, 

about 9 miles north of Sunnyside, about 1,500 feet north 

and 200 feet east of the southwest corner of sec. 1, T. 11 

N., R. 22 E. 

A11-0 to 3 inches; grayish brown (10YR 5/2) silt loam, very 

dark grayish brown (10YR 3/2) moist; weak fine granular 

structure; soft, very friable, nonsticky and slightly plastic; 

many fine roots; mildly alkaline; abrupt wavy boundary. 
A12-3 to 6 inches; brown (10YR 5/3) silt loam, dark 

brown (10YR 3/3) moist; weak fine angular blocky 

structure; slightly hard, friable, nonsticky and slightly 

plastic; common fine roots; few fine tubular pores; 

mildly alkaline; clear wavy boundary. 

B2-6 to 22 inches; brown (10R 5/3) silt loam, dark brown 

(10YR 3/3) moist; weak medium subangular blocky 

structure; slightly hard, friable, nonsticky and slightly 

plastic; common fine roots; common fine tubular pores; 

mildly alkaline; abrupt wavy boundary. 

C1-22 to 26 inches; brown (10R 5/3) silt loam, dark 

brown (10YR 3/3) moist; massive; slightly hard, 

friable, nonsticky and slightly plastic; common fine 

roots; few fine tubular pores; slightly effervescent; 

moderately alkaline; abrupt wavy boundary. 

C2ca-26 to 34 inches; pale brown (10YR 6/3) heavy silt 

loam, brown (10YR 4/3) moist; massive; hard, firm, 

slightly sticky and plastic; few very fine roots; many 

fine tubular pores; filaments of lime; violently 

effervescent; moderately alkaline; abrupt wavy 

boundary. 

C3casim-34 inches; lime- and silica-cemented duripan. 

Depth to the duripan is 20 to 40 inches. The duripan is 

underlain by basalt at a depth of 30 inches or more. The 

mollic epipedon is 12 to 15 inches thick. The A horizon has 

value of 4 or 5 when dry and 2 or 3 when moist. The B 

horizon has value of 5 or 6 when dry and 3 or 4 when moist, 

and it has chroma of 3 or 4 when moist or dry. The C1 and 

Cca horizons have value of 5 to 7 when dry and 3 to 5 when 

moist, and they have chroma of 2 to 4. 

Yakima series 

The Yakima series consists of very deep, well drained soils 

on flood plains. These soils formed in alluvium. Slopes 

range from 0 to 2 percent. Elevation is 700 to 1,200 feet. 

The average annual precipitation is 9 to 14 inches, the 

average annual air temperature is about 54 degrees F, and 

the average frost-free season is 120 to 170 days. 

Typical pedon of Yakima silt loam, about 1 mile 

southwest of Buena, about 2,440 feet east and 1,400 feet 

north of the southwest corner of sec. 21, T. 11 N., R. 20 E. 

Ap-0 to 6 inches; grayish brown (10YR 5/2) silt loam, 

very dark grayish brown (10YR 3/2) moist; weak 

moderate granular structure; hard, friable, slightly 

sticky and slightly plastic; many fine roots; common fine 

pores; mildly alkaline; abrupt smooth boundary. 

A12-6 to 13 inches; grayish brown (10YR 5/2) silt loam, 

very dark grayish brown (10YR 3/2) moist; weak 

moderate granular structure parting to weak moderate 

subangular blocky; hard, friable, slightly sticky and 

slightly plastic; few very fine roots; common fine 

pores; mildly alkaline; abrupt smooth boundary. 

A13-13 to 17 inches; dark grayish brown (10YR 4/2) 

sandy loam, very dark grayish brown (10R 3/2) moist; 

weak medium subangular blocky structure; soft, very 

friable, nonsticky and nonplastic; few very fine roots; 

common fine pores; 10 percent basalt pebbles; mildly 

alkaline; gradual wavy boundary. 

A14-17 to 27 inches; brown (10R 5/3) gravelly very fine 

sandy loam, dark brown (10YR 3/3) moist; weak 

medium subangular blocky structure; slightly hard, very 

friable, nonsticky and slightly plastic; few very fine 

roots; common fine pores; 20 percent basalt pebbles; 

neutral; gradual wavy boundary. 

C1-27 to 30 inches; brown (10R 5/3) gravelly very fine 

sandy loam, dark brown (10YR 3/3) moist; massive; 

slightly hard, very friable, nonsticky and nonplastic; few 

very fine roots; common fine pores; 30 percent basalt 

pebbles; neutral; abrupt wavy boundary. 

IIC2-30 to 60 inches; dark grayish brown (10YR 4/2) 

extremely gravelly coarse sand, very dark grayish 

brown (10YR 3/2) moist; single grain; loose; 60 

percent pebbles and 5 percent cobbles; few very fine 

roots; neutral. 

The mollic epipedon is 20 to 40 inches thick. The A 

horizon has value of 2 or 3 when moist, and it has chroma 

of 1 to 3 when moist or dry. The C horizon has value of 4 

or 5 when dry and 2 or 3 when moist, and it has chroma of 

2 or 3. It is gravelly loam, gravelly very fine sandy loam, or 

gravelly silt loam. The IIC horizon is very gravelly sand, very 

gravelly loamy sand, or extremely gravelly coarse sand. 

ZiIIah series 

The Zillah series consists of very deep, somewhat poorly 

drained soils on flood plains adjacent to the Yakima River. 

These soils formed in recent alluvium. Slopes range from 0 

to 2 percent. Elevation is 600 to 1,100 feet. The average 

annual precipitation is 6 to 9 inches, the average annual air 

temperature is about 49 degrees F, and the average frostfree season is 130 to 180 days. 

Typical pedon of Zillah silt loam, about 5 miles 

southwest of Sunnyside, about 300 feet north of the 

southeast corner of sec. 8, T. 9 N., R. 22 E. 
A11-0 to 6 inches; grayish brown (10YR 5/2) heavy silt 

loam, very dark grayish brown (10YR 3/2) moist; common 

fine prominent mottles that are dark reddish brown 

(5YR 3/4) when moist; moderate medium 

subangular blocky structure; slightly hard, 

friable, sticky and plastic; common fine roots; common 

fine pores; moderately alkaline; abrupt smooth 

boundary. 

A12-6 to 12 inches; grayish brown (10YR 5/2) silt loam, 

very dark grayish brown (10YR 3/2) moist; few fine 

prominent mottles that are dark reddish brown (5YR 

3/4) when moist; weak fine granular structure; slightly 

hard, friable, sticky and plastic; common fine roots; 

common fine pores; moderately alkaline; gradual wavy 

boundary. 

C1-12 to 42 inches; gray (10YR 6/1) heavy silt loam, dark 

gray (10YR 4/1) moist; many large prominent mottles 

that are dark reddish brown (5YR 3/4) when moist; 

massive; slightly hard, friable, sticky and 

plastic; few very fine roots; common fine pores; 

mildly alkaline; abrupt smooth boundary. 

IIC2-42 to 60 inches; gray (10YR 5/1) loamy sand, very 

dark gray (10YR 3/1) moist; single grain; loose; few 

very fine roots; mildly alkaline. 

Where these soils are not artificially drained, they are 

saturated with water at some period during the year. The 

profile is neutral to moderately alkaline. 

The A horizon has value of 4 or 5 when dry and 2 or 3 

when moist, and it has chroma of 1 or 2 when dry or moist. 

It is silt loam or sandy loam. 

The C horizon has value of 5 or 6 when dry and 3 or 4 

when moist, and it has chroma of 1 or 2 when moist or dry. 

It is silt loam or very fine sandy loam and has strata of 

loamy sand below a depth of 40 inches. The IIC horizon 

has value of 5 or 6 when dry and 3 or 4 when moist, and it 

has chroma of 1 or 2 when moist or dry. It is loamy sand, 

gravelly loamy sand, or very gravelly loamy sand. 
formation of the soils

Soil is defined as a natural three-dimensional body on the 

earth's surface that supports plants. As a natural body, a soil 

has properties that differ from those of the underlying 

bedrock or unconsolidated material that is not soil. 

Properties of soils are a reflection of soil forming processes 

that are initiated and sustained by the effects of climate and 

living organisms acting on parent material and modified by 

topography over a period of time. In a given area, one factor 

may exert a stronger influence on soil formation than 

another, but the interaction of all the factors determines the 

kind of soil that forms. 

In this survey, soil forming factors are discussed 

individually; however, the reader should be aware that 

there is a strong interdependence of all soil forming 

factors. 

climate 

Precipitation, by affecting the amount of water that enters 

the soil, influences the chemical and physical processes 

involved in the weathering of minerals, in erosion, and in 

leaching. Biological processes that determine the amount of 

residue returned to the soil and the rate at which the 

residue undergoes decomposition are dependent on 

moisture relationships in the soil forming environment. 

Temperature is a measure of the heat available for all 

physical, chemical, and biological processes involved in soil 

development. Heat, in the presence of adequate moisture, 

accelerates the weathering processes. Heat also 

increases evapotranspiration and thus reduces the amount 

of water available for chemical and geological processes. 

Most of the precipitation in the survey area occurs in 

winter. The amount and seasonal distribution of the 

precipitation, together with soil temperature, have 

influenced the weathering of the parent material. The 

degree of weathering is reflected by the depth to which 

carbonates have been leached and by the amount of clay 

that has been translocated. 

Soils in the 6- to 9-inch precipitation zone support 

grassland vegetation that is relatively low in productivity. 

Soils in this precipitation zone are partly recharged with 

moisture in winter. Because of low rainfall and high 

evapotranspiration, these soils are aridic but border on 

xeric. Organic matter content of the surface layer is 

relatively low. Some translocation of calcium carbonate 

from the solum and accumulation in the substratum are 

evident in Camborthids such as the Prosser, Scooteney, 

Shano, and Warden soils. 

Soils in the 8- to 12-inch precipitation zone support 

grassland vegetation. The soil moisture regime in this part of 

the survey area is aridic, but it borders on xeric. The 

precipitation in this zone has promoted more plant growth 

and a higher content of organic matter in the surface layer 

of these soils than in those of the 6- to 9-inch precipitation 

zone. Carbonates generally are leached deeper in this part 

of the survey area than in the lower precipitation zone. The 

Cleman and Ritzville soils formed in the 8- to 12-inch 

precipitation zone. Some soils in this precipitation zone have 

been leached sufficiently of carbonates for clay illuviation to 

have occurred. The argillic horizon in these soils is not 

strongly expressed. The Cowiche, Renslow, and Simcoe 

soils are examples of these soils. 

Soils in the 12- to 18-inch precipitation zone also support 

grassland vegetation. They have a xeric moisture regime. 

Carbonates have been leached from the profile of these 

soils. The mollic epipedon generally is darker colored than in 

soils that receive less precipitation. The agrillic horizon is 

more strongly developed and has a more pronounced 

structure. The McDaniel, Taneum, and Tieton soils are 

examples of these soils. 

Soils in the 16- to 40-inch precipitation zone support 

conifers. They do not have carbonates in the soil profile. 

Base saturation is less than 75 percent in some part of the 

soils within a depth of 30 inches from the surface. This is a 

result of the low base cycling of most conifers and the 

leaching of bases. The Carmack, Meystre, Tekison, Odo, 

Sutkin, and Jumpe soils are examples of these soils. 

In the extreme western part of the survey area, at 

elevations of 4,700 to 7,000 feet, precipitation is as high as 

50 inches and cryic temperatures prevail. This cool, moist 

climate produces soils with an A horizon that is high in 

content of organic matter because of the slow rate of 

decomposition. These soils are strongly influenced by 

volcanic ash, do not have carbonates, and have less than 50 

percent base saturation in the surface layer. Low base 

cycling, the leaching effects of high precipitation, and cold 

temperatures have influenced the development of the Naxing 

and Saydab soils. 
parent material 

Parent material is consolidated or unconsolidated mineral 

material. The formation of soils results from changes in the 

parent material. The nature of the changes involved is 

strongly influenced by the character of the parent material, 

particularly by its mineralogy and texture. Mineralogy and 

texture affect various physical and chemical aspects of 

the soil forming environment. 

Parent material in the survey area includes recent 

alluvium; material derived from Yakima Basalt; 

loess; lacustrine sediment; material derived from 

siltstone, sandstone, and conglomerate of the 

Ellensburg Formation; volcanic ash; and eolian 

sand. 

Most of the soils on terraces and uplands formed in 

loess. They are underlain by basalt, by a duripan, or 

by lacustrine sediment. The soils that formed in loess are 

dominantly silt loam. Soils of the Shano, Ritzville, and 

Renslow series are examples Of these soils. 

Warden soils formed in a thin mantle of loess over 

stratified glaciolacustrine sediment known as the Touchet 

Formation. This late Pleistocene sediment is not well 

laminated. The Hezel soils formed in a mantle of eolian sand 

over glaciolacustrine sediment of the Touchet Formation. 

Quincy soils formed in very deep eolian sand. These soils 

are dominantly loamy fine sand and are somewhat 

excessively drained. 

Some of the soils in the survey area formed in loess over 

a lime- and silica-cemented duripan, and others formed 

over a silica-cemented duripan. The genesis of the duripan is 

not entirely understood. A commonly accepted theory is that 

the duripan is a relict feature associated with a previous soil 

forming cycle. It is thought to be an erosional remnant of an 

ancient soil. The upper material was eroded away during the 

late Pleistocene. The loess presently overlying the duripan is 

dominantly Holocene in age. The Willis, Burke, Scoon, and 

Moxee soils formed in a mantle of loess over a lime- and 

silica-cemented duripan. The Harwood, Gorst, and 

Gorskel soils formed in a thin mantle of loess over a silicacemented duripan. 

Some of the soils in the survey area formed in a mixture 

of loess and underlying sandstone of the Ellensburg 

Formation. The Cowiche, Taneum, and Meystre soils are 

examples of these soils. The Roza soils formed in fine 

textured material of the Ellensburg Formation. These soils 

have a high shrink-swell potential and are characterized by 

wide cracks in the surface that extend to a depth of 20 

inches or more when the soils are dry. The Roza soils 

are Xerertic Camborthids. 

Soils that formed in loess mixed with residuum and 

colluvium derived from basalt are those of the Bakeoven, 

Clint, Jumpe, McDaniel, Sapkin, and Sutkin series. The 

Loneridge and Tekison soils also formed in material derived 

from basalt and have accumulations of clay in the subsoil. 

Soils that formed in material weathered from basalt with 

additions of volcanic ash and loess are those of the Naxing 

and Saydab series. Because of the properties of weathered 

volcanic ash, these soils have low bulk density. They are 

medial-skeletal Andic Cryumbrepts. 

The most recent soil parent material is the Quaternary 

alluvium that is in stream valleys throughout the survey area. 

Soils of the Esquatzel, Kittitas, Fiander, Zillah, Umapine, and 

Outlook series formed in alluvium and have a silty control 

section. The Wenas, Toppenish, and Cleman soils are more 

influenced by sand or by sand and gravel, and they have a 

loamy ;control section. The Weirman and Mippon soils are 

sandy-skeletal and are near major drainageways. The Logy, 

Ashue, and Track soils are loamy-skeletal. 

topography 

Topography influences the soil forming processes by 

affecting runoff, drainage, and microclimate. In nearly level 

areas, runoff is very slow. Much of the water drains through 

the soil, and some evaporates. In sloping to steep areas, 

runoff generally increases with increasing slope. The more 

water that enters the soil, the greater the depth to which the 

soil is leached and weathered. The topography, through 

variations in exposure to the sun and wind and in air 

drainage, creates noticeable differences in vegetation and 

soil properties within short distances. For example, southfacing slopes receive more direct radiation from the sun than 

do the north-facing slopes. Consequently, south-facing 

slopes are warmer and drier. 

Aspect has influenced the amount of loess that has 

accumulated. South and southwest aspects are exposed to 

the prevailing wind, and thus loess accumulation is less on 

these aspects than on north aspects. Also, because of the 

higher evapotranspiration rate on south and southwest 

aspects, plant density is less than on north aspects. With 

decreased plant density, the potential for water erosion 

becomes greater on south and southwest aspects. 

Representative soils that are on south and southwest 

aspects are the moderately deep Burke and Willis soils. 

Examples of soils on north aspects are the deep and very 

deep Ritzville and Shano soils. Water erosion in some areas 

has moved loess downslope. There has been little 

accumulation of loess on the edges of ridgetops and on 

narrow ridges. The Bakeoven, Bocker, and Rock Creek soils 

formed in residuum and colluvium derived from basalt in 

these areas. 

Local relief modifies the moisture regime of soils. This is 

especially evident in soils on bottom lands. Possibly as a 

result of overirrigation, runoff from adjacent upland soils 

accumulates on bottom lands. A seasonal high water table is 

common in some of the soils on bottom lands. Mottling gives 

evidence of reducing regimes. Examples of soils that exhibit 

mottling and are somewhat 
poorly drained are the Haplaquolls such as the Kittitas, 

Toppenish, Track, Wenas, and Zillah soils. These soils are 

along the Yakima, Naches, and Wenas Rivers. Some well 

drained soils on bottom lands are the Esquatzel, Clemen, 

Logy, and Yakima soils. 

In some areas where the free water in the soil contains 

salts and is sufficiently close to the surface, 

evapotranspiration concentrates the salts in the surface 

layer. Included among these soils are the Fiander, Kittitas, 

Outlook, Sinloc, Umapine, and Wanser soils. 

living organisms 

The major biotic factor in soil development is vegetation. 

It is the principal source of the organic matter responsible for 

various chemical and physical properties of soils. Rodents, 

earthworms, and various other animals and insects assist in 

decomposing organic substances, and they mix the soil as a 

consequence of their burrowing activities. 

The influence of vegetation is most evident in the A 

horizon. Plant species, productivity, and the rate at which 

residue decomposes strongly influence the properties of the 

A horizon. Dark colors in the A horizon generally indicate 

high organic matter content. Soils that receive about 6 to 16 

inches of precipitation support grassland vegetation. Many of 

the soils that receive more than 16 inches of precipitation 

support coniferous forest. A relationship exists between the 

kind and amount of plant production and the color and 

thickness of the A horizon. Grass generally produces more 

organic matter in the A horizon than trees. Where plant 

production is high, the A horizon is thicker or darker colored 

than where production is low. The color and thickness of the 

A horizon of the Ritzville, Taneum, and Meystre soils reflect 

the influence of higher plant production than those of the 

Prosser, Shano, and Warden soils. 

Soils on bottom lands contain the most organic matter 

relative to precipitation. One of the reasons is the relatively 

higher plant production stimulated by the accumulation of 

runoff from adjacent upland soils. Some soils formed under 

the influence of a seasonal high water table that reduces 

the rate of decomposition of organic matter. This is because 

of poor soils aeration, which reduces the activity of microorganisms. The Wenas soil is an example of these soils. 

Soils under forest vegetation are more leached of bases 

and other products of weathering than soils under grasses. 

One reason for the lower base saturation is the acidity of the 

leaching water under a coniferous forest canopy. Base 

saturation is less than 75 percent in the solum of the 

Carmack, Sutkin, and Tekison soils. 

An ochric epipedon is common on the more densely 

forested soils. The Jumpe and Loneridge soils are 

examples of these soils. However, a thick, dark-colored 

A horizon is typical of soils in coniferous forests in the cryic 

temperature regime. One reason is the reduced biological 

activity of micro-organisms in cold temperatures, which 

results in reduced decomposition of organic matter. The 

Naxing and Saydab soils are examples of these soils. 

time 

Soil formation begins as soon as rock is exposed on the 

earth's surface. As soil formation progresses, characteristic 

layers called horizons form within the soil profile. Generally, 

the larger the number of horizons and the greater their 

thickness and distinctness, the more mature is the soil. 

Depending on the nature of the parent material and the vigor 

of the soil forming process, it takes hundreds or even 

thousands of years to form pronounced genetic horizons. 

The parent material in the survey area is material 

derived from basalt and the Ellensburg Formation of 

Miocene age, stream terrace sand and gravel of 

Pleistocene and Pliocene age, volcanic ash of 

Pleistocene and Recent age, and Recent alluvium. 

The soils in the area have been forming since Pliocene 

time. Some soils on basalt uplands have a strongly 

expressed argillic horizon. The Loneridge, Tekison, and 

Rock Creek soils are examples of these soils. A duripan 

formed in many of the soils on terraces during that time. 

Many of these soils since have been eroded to the duripan. 

Loess has been deposited in Pleistocene and Recent times 

over this old duripan, and a new soil is now forming in the 

loess. Stratigraphic studies in the Columbia Basin (25) 

indicate that the duripan is pre-Bull Lake in age (more than 

50,000 years old). The Harwood, Gorst, and Gorskel soils 

are examples of these soils. 

During the late Pleistocene (13,000 to 18,000 years ago) 

glacial water covered parts of the survey area. The parent 

material for the Warden, Scooteney, and Finley soils was 

deposited during this time. 

Some of the younger soils in the area formed in recent 

alluvium on bottom lands, which are the youngest landforms 

in the area and are subject to flooding. These soils generally 

have an AC profile. The Esquatzel, Umapine, Weirman, and 

Yakima soils are examples of these soils. 

Man's influence in the survey area has been considerable. 

Since the advent of irrigation, for example, overirrigation of 

soils in the higher lying areas has produced saline-alkali 

soils in the lower lying areas. The Outlook and Sinloc soils 

are examples of these soils. Through irrigation, land leveling, 

soil erosion, and alteration of native plant communities, 

man's presence will remain a highly significant soil forming 

factor in this survey area. 
references 

(1) American Association of State Highway [and 

Transportation; Officials. 1970: Standard specifications 

for highway materials and methods of sampling and 

testing. Ed. 10, 2 vol., illus. 

(2) American Society for Testing and Materials. 1974. 

Method for classification of soils for engineering 

purposes. ASTM Stand. D 2487-69. In 1974 Annual 

Book of ASTM Standards, Part 19, 464 pp., illus. 

(3) Alexander, Robert R. 1966. Site indexes for lodgepole 

pine, with corrections for stand density: Instructions for 

field use. U.S. Dep. Agric., Forest Serv., Rocky 

Mountain Forest and Range Exp. Stn. Res. Pap. RM24, 7 pp. 

(4) Alexander, Robert R. 1967. Site indexes for Englemann 

spruce in the central Rocky Mountains. U.S. Dep. 

Agric., Forest Serv., Rocky Mountain Forest and 

Range Exp. Stn. Res. Pap. RM-32, 7 pp., illus. 

(5) Ballard, James K. 1978. Frost and frost control in 

Washington orchards. Wash. State Univ., Agric. 

Res. Center Ext. Bull. 634, 26 pp. 

(6) Bega, Robert V. 1978. Diseases of Pacific Coast 

conifers. U.S. Dep. Agric., Forest Serv., Pacific 

Southwest Forest and Range Exp. Stn., Agric. 

Handb. 521, 206 pp., illus. 

(7) Bingham, James W. and Maurice J. Grolier. 

1966. The Yakima Basalt and Ellensburg Formation 

of south-central Washington. U.S. Geol. Surv. 

Bull. 1224-G, 15 pp., illus. 

(8) Dolph, R. E. and L. F. Pettinger. 1968. Forest insect 

conditions in the Pacific Northwest during 1967. U.S. 

Dep. Agric., Forest Serv., Insect and Disease Control 

Br., Div. of Timber Mgmt., Pacific Northwest Region, 73 

pp. 

(9) Edminster, Carleton B. 1980. Yields per acre of 

Englemann spruce and subalpine fir. U.S. Dep. 

Agric., Soil Conserv. Serv., West Tech. Serv. 

Center Bull. No. W38-0-17, 7 pp. 

(10) Fenneman, Nevin M. 1931. Physiography of 

western United States. 534 pp., illus_ 

(11) Franklin, Jerry F. and C. T. Dyrness. 1973. Natural 

vegetation of Oregon and Washington. U.S. Dep. 

Agric., Pacific Northwest Forest and Range Exp. Stn. 

Gen. Tech. Rep. PNW-8, 417 pp., illus. 

(12) Furniss, R. L. and V. M. Carolin. 1977. Western 

forest insects. U.S. Dep. Agric., Forest Serv., Misc. 

Pub[. No. 1339, 654 pp., illus. 

(13) MacLean, Colin D. and Charles L. Bolsinger. 

1973. Estimating productivity on sites with a low 

stocking capacity. U.S. Dep. Agric., Pacific Northwest 

Forest and Range Exp. Stn. Res. Pap. PNW-152, 18 

pp., illus. 

(14) MacLean, Colin D. 1979. Relative density: the key to 

stocking assessment in regional analysis and a forest 

survey viewpoint. U.S. Dep. Agric., Pacific 

Northwest Forest and Range E xp. Stn. e^ Tech. Rep. 

PNW-78, 5 pp. 

(15) Meyer, W. H. 1961. Yield of even-aged stands of 

ponderosa pine. U.S. Dep. Agric. Tech. Bull. 630, 59 

pp., illus. 

(16) Mitchell, Russel G. 1966. Infestation characteristics of 

the balsam woolly aphid in the Pacific Northwest. U.S. 

Dep. Agric., Pacific Northwest Forest and Range Exp. 

Stn. Res. Pap. PNW-35, 18 pp., illus. 

(17) Myers, Clifford A. 1967. Yield tables for managed 

stands of lodgepole pine in Colorado and Wyoming. 

U.S. Dep. Agric., Rocky Mountain Forest and Range 

Exp. Stn. Res. Pap. RM-26, 20 pp. 

(18) Schmidt, Wyman C., Raymond C. Shearer, and Arthur 

L. Roe. 1976. Ecology and silviculture of western 

larch forests. U.S. Dep. Agric., Intermountain Forest 

and Range Exp. Stn., Tech. Bull. No. 1520, 96 pp., 

illus. 

(19) Smith, L. H. 1958. Soil survey of Yakima County, 

Washington. U.S. Dep. Agric., Soil Conserv. Serv., 143 

pp., illus. 

(20) Society of American Foresters. 1954. Forest cover 

types of North America. Rep. Comm. Forest Types, 67 

pp. 

(21) United States Department of Agriculture. 1951. Soil 

survey manual. U.S. Dep. Agric. Handb. 18, 503 

pp., illus. (Supplements replacing pp. 173-188 issued 

May 1962) 

(22) United States Department of Agriculture. 1954. 

Diagnosis and improvement of saline and alkali 

soils. U.S. Dep. Agric. Handb. 60, 160 pp., 

illus. 

(23) United States Department of Agriculture. 1975. Soil 

taxonomy: A basic system of soil classification for 

making and interpreting soil surveys. Soil 

Conserv. Serv., U.S. Dep. Agric. Handb. 436, 754 

pp., illus. 

(24) Washington State Department of Natural Resources. 

1962. Eastside-true fir site tables. Original inventory site 

trees, 1 p. 
(25) Webster, G. D., Victor R. Baker, and Carl Gustafson. 

1976. Channeled scablands in southeastern 

Washington, A roadlog via Spokane, Coulee City, 

Vantage, Washtucna, Lewiston, and Pullman. Field 

Guide No. 2. 72nd Annual Meeting, Geol. Soc. Am., 25 

pp., illus. 

(26) Yakima County Planning Department. 1977. 

Comprehensive plan, Yakima County. 43 pp., 

illus. 
glossary 

Alkali (sodic) soil. A soil having so high a degree of 

alkalinity (pH 8.5 or higher), or so high a percentage of 

exchangeable sodium (15 percent or more of the total 

exchangeable bases), or both, that plant growth is 

restricted. 

Alluvium. Material, such as sand, silt, or clay, deposited on 

land by streams. 

Area reclaim (in tables). An area difficult to reclaim after the 

removal of soil for construction and other uses. 

Revegetation and erosion control are extremely difficult.

Available water capacity (available moisture 

capacity). The capacity of soils to hold water available 

for use by most plants. It is commonly defined as the 

difference between the amount of soil water at field 

moisture capacity and the amount at wilting point. It is 

commonly expressed as inches of water per inch of 

soil. The capacity, in inches, in a 60-inch profile or to a 

limiting layer is expressed asInches 

Low ....................................................... Less than 3.75 

Moderate...............................................................3.75 to 5 

Moderately high...................................................... 5 to 7.5 

High ............................................................. More than 7.5 

Basal area (forestry). The area of a cross section of a tree 

(including bark), usually expressed in square feet, and 

usually referring to the section at breast height. The 

basal area of a stand is the sum of the basal areas of 

individual trees and is computed per acre. 

Bedrock. The solid rock that underlies the soil and other 

unconsolidated material or that is exposed at the 

surface. 

Bottom land. The normal flood plain of a stream, 

subject to flooding. 

Cable yarding. A method of moving felled trees to a nearby 

central area for transport to a processing facility. Most 

cable yarding systems involve use of a winch with poles 

and pulleys to suspend and control the movement of 

wire cables. To reduce friction and soil disturbance, 

felled trees generally are yarded in with one end lifted or 

the entire log is suspended. 

Calcareous soil. A soil containing enough calcium 

carbonate (commonly combined with 

magnesium carbonate) to effervesce visibly when 

treated with cold, dilute hydrochloric acid. 

Caliche. A more or less cemented deposit of calcium 

carbonate in soils of warm-temperate, subhumid to arid 

areas. Caliche occurs as soft, thin layers in the soil or 

as hard, thick beds just beneath the solum, or it is 

exposed at the surface by erosion. 

Chiseling. Loosening the soil, without inverting the soil 

material and with minimum of mixing of the surface 

soil, to shatter restrictive layers (in the upper 16 inches) 

that inhibit water movement and root development. 

Clay. As a soil separate, the mineral soil particles less than 

0.002 millimeter in diameter. As a soil textural class, 

soil material that is 40 percent or more clay, less than 

45 percent sand, and less than 40 percent silt. 

Clay film. A thin coating of oriented clay on the surface of a 

soil aggregate or lining pores or root channels. 

Coarse fragments. Mineral or rock particles 2 

millimeters to 25 centimeters (10 inches) in 

diameter. 

Coarse textured (light textured) soil. Sand or loamy 

sand. 

Cobble. A rounded or partly rounded fragment of rock 3 to 

 10 inches (7.5 to 25 centimeters) in diameter. 

Codominant trees. Well developed trees that are part of 

the main canopy but are subject to some competition 

from other trees. 

Colluvium. Soil material, rock fragments, or both moved by 

creep, slide, or local wash and deposited at the base of 

steep slopes. 

Concretions. Grains, pellets, or nodules of various sizes, 

shapes, and colors consisting of concentrated 

compounds or cemented soil grains. The composition of 

most concretions is unlike that of the surrounding soil. 

Calcium carbonate are common compounds in 

concretions. 

Consistence, soil. The feel of the soil and the ease with 

which a lump can be crushed by the fingers. Terms 

commonly used to describe consistence areLoose. -Noncoherent when dry or moist; does not hold 

together in a mass. 

Friable.-When moist, crushes easily under gentle 

pressure between thumb and forefinger and can be 

pressed together into a lump. 

Firm.-When moist, crushes under moderate pressure 

between thumb and forefinger, but resistance is distinctly 

noticeable. 
Plastic.-When wet, readily deformed by moderate 

pressure but can be pressed into a lump; will form a 

"wire" when rolled between thumb and forefinger. 

Sticky.-When wet, adheres to other material and tends 

to stretch somewhat and pull apart rather than to pull 

free from other material. 

Hard.-When dry, moderately resistant to pressure; can 

be broken with difficulty between thumb and forefinger. 

Soft.-When dry, breaks into powder or individual 

grains under very slight pressure. 

Cemented.-Hard; little affected by moistening. 

Corrugations. Small channels used to carry water for 

surface irrigation of close-growing, noncultivated crops 

such as legumes, grasses, small grain, and mint. Water 

flowing through the corrugations soaks into the soil and 

spreads laterally, irrigating the areas between furrows. 

Cover crop. A crop of close-growing grasses, legumes, or 

small grain grown to control seasonal erosion or for 

permanent cover in orchards and vineyards. 

Culmination of the mean annual increment (CMAI). 

The average yearly volume growth of a stand of trees 

from the year of origin to the age that gives the 

highest average. 

Cutbanks cave (in tables). The walls of excavations 

tend to cave in or slough. 

Deferred grazing. Postponing grazing or resting grazing for 

a prescribed period. 

Depth to rock (in tables). Bedrock is too near the 

surface for the specified use. 

Diameter at breast height. The diameter of a tree 

(including bark), usually expressed in inches, measured 

at a height of 4.5 feet above the average ground level. 

Diversion. A channel that has a supporting ridge 

constructed across the slope on the lower side to divert 

excess water to sites where it can be used or disposed 

of safely. 

Dominant trees. The largest, tallest, and most vigorous 

trees in a stand. 

Drainage class (natural). Refers to the frequency and 

duration of periods of saturation or partial saturation 

during soil formation, as opposed to altered drainage, 

which is commonly the result of artificial drainage or 

irrigation but may be caused by the sudden deepening 

of channels or the blocking of drainage outlets. Seven 

classes of natural soil drainage are recognized: 

Somewhat excessively drained.-Water is removed 

from the soil rapidly. Many somewhat excessively 

drained soils are sandy and rapidly pervious. Some are 

shallow. Some are so steep that much of the water 

they receive is lost as runoff. All are free of the mottling 

related to wetness. 

Well drained.-Water is removed from the soil readily, 

but not rapidly. It is available to plants 

throughout most of the growing season, and wetness 

does not inhibit growth of roots for significant periods 

during most growing seasons. Well drained soils are 

commonly medium textured. They are mainly free of 

mottling. 

Somewhat poorly drained.-Water is removed slowly 

enough that the soil is wet for significant periods during 

the growing season. Wetness markedly restricts the 

growth of mesophytic crops unless artificial drainage is 

provided. Somewhat poorly drained soils commonly 

have a slowly pervious layer, a high water table, 

additional water from seepage, nearly continuous 

rainfall, or a combination of these. 

Poorly drained.-Water is removed so slowly that the 

soil is saturated periodically during the growing season 

or remains wet for long periods. Free water is 

commonly at or near the surface for long enough 

during the growing season that most mesophytic crops 

cannot be grown unless the soil is artificially drained. 

The soil is not continuously saturated in layers directly 

below plow depth. Poor drainage results from a high 

water table, a slowly pervious layer within the profile, 

seepage, nearly continuous rainfall, or a combination of 

these. 

Drip irrigation. Very slow (about 1 gallon per hour), frequent 

applications of irrigation water. Water is applied through 

plastic emitters that normally are placed around the 

base of the plant commonly measured with a 

tensiometer. Drip irrigation helps to prevent the 

depletion of oxygen in the soil and allows optimum 

combinations of water and oxygen for plant growth. 

Duff. A term used to identify a generally firm organic 

layer on the surface of mineral soils. It consists of 

fallen plant material that is in the process of 

decomposition and includes everything from the litter 

on the surface to underlying pure humus. 

Duripan. A cemented layer. The layer normally is 

cemented by silica or calcium carbonate, or both. 

Eolian soil material. Earthy parent material accumulated 

through wind action; commonly refers to sandy material 

in dunes or to loess in blankets on the surface. 

Fallow (or summer fallow). Cropland left idle every other 

year in rotation with small grain. Weeds are 

controlled and moisture conserved during the idle 

year to retain adequate moisture for the cropping 

year. This 2-year rotation is common in regions of 

limited rainfall. 

Field moisture capacity. The moisture content of a soil, 

expressed as a percentage of the ovendry weight, after 

the gravitational, or free, water has drained away; the 

field moisture content 2 or 3 days after a soaking rain. 
Fill slope. A sloping surface consisting of excavated soil 

material from a road cut. It is commonly on the 

downhill side of the road. 

Firebreak. Areas cleared of flammable material to stop or 

help to control creeping or running fires. It also serves 

as a line from which to work and to facilitate the 

movement of men and equipment in fire fighting. 

Designated roads also serve as firebreaks. 

Forb. Any herbaceous plant not a grass or a sedge. 

Forest cover type. A descriptive term used to group stands 

of similar character as regards species composition and 

development because of ecological factors. 

Furrow. Small channels used to carry water for surface 

irrigation of cultivated crops planted in rows. Water 

flowing in the furrows soaks into the soil and spreads 

laterally, irrigating the areas between furrows. 

Genesis, soil. The mode of origin of the soil. Refers 

especially to the processes or soil-forming factors 

responsible for the formation of the solum, or true 

soil, from the unconsolidated parent material. 

Grassed waterway. A natural or constructed waterway, 

typically broad and shallow, seeded to grass as 

protection against erosion. 

Gravel. Rounded or angular fragments of rock up to 3 

inches (2 millimeters to 7.5 centimeters) in diameter. An 

individual piece is a pebble. 

Grazable woodland. Forest land that produces, at least for 

a time, sufficient understory vegetation suitable for 

forage that can be grazed without significantly impairing 

the production of wood and other forest products. 

Gully. A severely eroded site that has steep ditches cut by 

concentrated running water that ordinarily flows only 

after runoff. The distinction between a gully and a rill is 

one of depth and location. A gully generally is an 

obstacle to farm machinery and is too deep to be 

obliterated by ordinary tillage. A rill is less than 1 foot 

deep and generally can be smoothed over by ordinary 

tillage. 

Hardpan. A hardened or cemented soil horizon, or layer. 

The soil material is sandy, loamy, or clayey and is 

cemented by iron oxide, silica, calcium carbonate, or 

other substance. 

Horizon, soil. A layer of soil, approximately parallel to the 

surface, having distinct characteristics produced by soilforming processes. In the identification of soil horizons, 

an upper case letter represents the major horizons. 

Numbers or lower case letters that follow represent 

subdivisions of the major horizons. An explanation of the 

subdivisions is given in the Soil Survey Manual. The 

major horizons of mineral soil are as follows: 

O horizon.-An organic layer of fresh and decaying 

plant residue at the surface of a mineral soil. 

A horizon.-The mineral horizon at or near the surface 

in which an accumulation of humified organic matter is 

mixed with the mineral material. Also, a plowed 

surface horizon, most of which was originally part of a 

B horizon. 

B horizon.-The mineral horizon below an A horizon. The 

B horizon is in part a layer of transition from the 

overlying A to the underlying C horizon. The B horizon 

also has distinctive characteristics such as (1) 

accumulation of clay, sesquioxides, humus, or a 

combination of these; (2) prismatic or blocky structure; 

(3) redder or browner colors than those in the A horizon; 

or (4) a combination of these. The combined A and B 

horizons are generally called the solum, or true soil. If a 

soil does not have a B horizon, the A horizon alone is 

the solum. 

C horizon.-The mineral horizon or layer, excluding 

indurated bedrock, that is little affected by soil-forming 

processes and does not have the properties typical of 

the A or B horizon. The material of a C horizon may be 

either like or unlike that in which the solum formed. If the 

material is known to differ from that in the solum, the 

Roman numeral II precedes the letter C. 

R layer.-Consolidated rock beneath the soil. The 

rock commonly underlies a C horizon, but can be 

directly below an A or a B horizon. 

Illuviation. The movement of soil material from one 

horizon to another in the soil profile. Generally, 

material is removed from an upper horizon and 

deposited in a lower horizon. 

Infiltration rate. The rate at which water penetrates the 

surface of the soil at any given instant, usually 

expressed in inches per hour. The rate can be limited 

by the infiltration capacity of the soil or the rate at which 

water is applied at the surface. 

Intake rate. The average rate of water entering the soil 

under irrigation. Most soils have a fast initial rate; the 

rate decreases with application time. Therefore, intake 

rate for design purposes is not a constant but is a 

variable depending on the net irrigation application. 

Irrigation. Application of water to soils to assist in 

production of crops. Methods of irrigation areCorrugation.-Water is applied to small, closely spaced 

furrows or ditches in fields of close-growing crops or in 

orchards so that it flows in only one direction. 

Drip (or trickle).-Water is applied slowly and under low 

pressure to the surface of the soil or into the soil 

through such applicators as emitters, porous tubing, or 

perforated pipe. 

Furrow.-Water is applied in small ditches made by 

cultivation implements. Furrows are used for tree and 

row crops. 

Sprinkler.-Water is sprayed over the soil surface 

through pipes or nozzles from a pressure system. 
Subirrigation.-Water is applied in open ditches or tile lines 

until the water table is raised enough to wet the soil. 

Wild flooding.-Water, released at high points, is 

allowed to flow onto an area without controlled 

distribution. 

Lacustrine deposit (geology). Material deposited in lake water 

and exposed when the water level is lowered or the elevation 

of the land is raised. 

Large stones (in tables). Rock fragments 3 inches (7.5 

centimeters) or more across. Large stones adversely affect 

the specified use of the soil. 

Leaching. The removal of soluble material from soil or other 

material by percolating water. 

Liquid limit. The moisture content at which the soil 

passes from a plastic to a liquid state. 

Loam. Soil material that is 7 to 27 percent clay particles, 28 to 

50 percent silt particles, and less than 52 percent sand 

particles. 

Loess. Fine grained material, dominantly of silt-sized 

particles, deposited by wind. 

Meadow farmed (mint). A cultural practice that consists of using 

tillage only during establishment of the mint crop. In some 

instances, the original corrugations are reestablished if 

water does not stay in the corrugations or flow to the end of 

the field. 

Mean annual increment. The average yearly volume growth of 

a stand of trees from the year of origin to the age under 

consideration. 

Minimum tillage. Properly timed noninversion conservation 

tillage that is limited to only those operations essential to 

crop production and prevention of soil damage. The 

purpose of minimum tillage is to avoid deterioration of soil 

structure; to reduce soil compaction and formation of a 

tillage pan; to improve soil aeration, permeability, tilth; and 

to maintain residue on the surface. 

Mottling, soil. Irregular spots of different colors that vary in 

number and size. Mottling generally indicates poor 

aeration and impeded drainage. Descriptive terms are as 

follows: abundance-few, common, and many, size-fine, 

medium, and coarse; and contrast-faint, distinct, and 

prominent. The size measurements are of the diameter 

along the greatest dimension. Fine indicates less than 5 

millimeters (about 0.2 inch); medium, from 5 to 15 millimeters 

(about 0.2 to 0.6 inch); and coarse, more than 15 millimeters 

(about 0.6 inch). 

Munsell notation. A designation of color by degrees of the three 

simple variables-hue, value, and chroma. For example, a 

notation of 1 OYR 6/4 is a color of 10YR hue, value of 6, 

and chroma of 4. 

Natural reforestation. Seedlings that become established from 

seed disseminated by nearby cone 

bearing trees. The expected period of time it takes for an 

area to naturally reforest is described by the terms readily, 

seedlings adequately occupy the area in 2 to 5 years; 

periodically, 5 to 10 years; and infrequently, 10 to 20 

years. 

Normal stand (woodland). A normal stand, at a given age, 

contains as many trees per acre as can properly use 

the growing space available. It is considered to be fully 

stocked. 

Nurse crop. A companion crop grown to protect some other 

crop sown with it. 

Organic matter. Plant and animal residue in the soil in various 

stages of decomposition. 

Outwash plain. A landform of mainly sandy or coarse textured 

material of glaciofluvial origin. An outwash plain is 

commonly smooth; where pitted, it is generally low in 

relief. 

Pan. A compact, dense layer in a soil that impedes the 

movement of water and the growth of roots. For 

example, hardpan, fragipan, claypan, plowpan, and traffic 

pan. 

Parent material. The unconsolidated organic and 

mineral material in which soil forms. 

Pedon. The smallest volume that can be called "a soil." A 

pedon is three dimensional and large enough to permit 

study of all horizons. Its area ranges from about 10 to 100 

square feet (1 square meter to 10 square meters), depending 

on the variability of the soil. 

Percs slowly (in tables). The slow movement of water 

through the soil adversely affecting the specified use. 

Permeability. The quality of the soil that enables water to move 

downward through the profile. Permeability is measured 

as the number of inches per hour that water moves 

downward through the saturated soil. Terms describing 

permeability are: 

Very slow............................................. less than 0.06 inch 

Slow.........................................................0.06 to 0.20 inch 

Moderately slow ..........................................0.2 to 0.6 inch 

Moderate........................................ 0.6 inch to 2.0 inches 

Moderately rapid ..................................... 2.0 to 6.0 inches 

Rapid........................................................ 6.0 to 20 inches 

Very rapid..........................................more than 20 inches 

Planned grazing system. A system in which two or more 

grazing units are alternately rested from grazing in a 

planned sequence over a period of years. The rest 

period can be throughout the year during the growing 

season of the key plants. 

Profile, soil. A vertical section of the soil extending through 

all its horizons and into the parent material. 

Proper grazing use. Grazing at an intensity that maintains 

enough cover to protect the soil and maintain or improve 

the quantity and quality of the desirable vegetation. 
Reaction, soil. A measure of acidity or alkalinity of a soil, 

expressed in pH values. A soil that tests to pH 7.0 is 

described as precisely neutral in reaction because it is 

neither acid nor alkaline. The degree of acidity or 

alkalinity is expressed aspH 

Extremely acid Below 4.5 

Very strongly acid 4.5 to 5.0 

Strongly acid 5.1 to 5.5 

Medium acid 5.6 to 6.0 

Slightly acid 6.1 to 6.5 

Neutral 6.6 to 7.3 

Mildly alkaline 7.4 to 7.8 

Moderately alkaline 7.9 to 8.4 

Strongly alkaline 8.5 to 9.0 

Very strongly alkaline 9.1 and higher 

Reforestation. Tree seedlings that are planted or are 

naturally established in an area of land that was once 

forested. It includes the practices associated with 

planting. 

Residuum (residual soil material). Unconsolidated, 

weathered, or partly weathered mineral material that 

accumulated as consolidated rock disintegrated in 

place. 

Rill. An obvious erosion pattern resulting from rainfall or 

runoff from snowmelt. Usually referred to as sheet and 

rill erosion. See `gully` for more detail. 

Road cut. A sloping surface produced by mechanical 

means during road construction. It is commonly on the 

uphill side of the road. 

Rooting depth (in tables). Shallow root zone. The soil is 

shallow over a layer that greatly restricts roots. 

Runoff. The precipitation discharged into stream channels 

from an area. The water that flows off the surface of 

the land without sinking into the soil is called surface 

runoff. Water that enters the soil before reaching 

surface streams is called groundwater runoff or 

seepage flow from ground water. 

Saline soil. A soil containing soluble salts in an amount 

that impairs growth of plants. A saline soil does 

not contain excess exchangeable sodium. 

Sand. As a soil separate, individual rock or mineral 

fragments from 0.05 millimeter to 2.0 millimeters in 

diameter. Most sand grains consist of quartz. As a soil 

textural class, a soil that is 85 percent or more sand 

and not more than 10 percent clay. 

Sandstone. Sedimentary rock containing dominantly 

sand-size particles. 

Seepage (in tables). The movement of water through the 

soil. Seepage adversely affects the specified use. 

Sheet erosion. The removal of a fairly uniform layer of soil 

material from the land surface by the action of rainfall 

and runoff water. 

Shrink-swell. The shrinking of soil when dry and the 

swelling when wet. Shrinking and swelling can 

damage roads, dams, building foundations, and 

other structures. It can also damage plant roots. 

Silt. As a soil separate, individual mineral particles that 

range in diameter from the upper limit of clay (0.002 

millimeter) to the lower limit of very fine sand (0.05 

millimeter). As a soil textural class, soil that is 80 

percent or more silt and less than 12 percent clay. 

Site curve (50-year). A set of related curves on a graph that 

shows the average height of dominant trees for a range 

of ages on soils that differ in productivity. Each level is 

represented by a curve. 

Site curve (100-year). A set of related curves on a graph 

that shows the average height of dominant and 

codominant trees for a range of ages on soils that 

differ in productivity. Each level is represented by a 

curve. 

Site index. The height that dominant or dominant and 

codominant trees reach at 50 years total age, of breast 

height age, of 100 years total age, or at breast height 

age. With this index and the age of the stand of trees, 

yield can be determined by using the appropriate yield 

table. 

Skid trail. The path left by skidded logs and by the 

equipment used to pull them. 

Skidding. A method of moving felled trees to a nearby, 

central area for transport to a processing facility. Most 

skidding systems involve pulling the trees with wire 

cables attached to a bulldozer or rubber-tired tractor. To 

reduce friction and soil disturbance, felled trees 

generally are pulled with one end lifted. 

Slick spot. A small area of soil having a puddled, crusted, 

or smooth surface and an excess of exchangeable 

sodium. The soil is generally silty or clayey, is slippery 

when wet, and is low in productivity. 

Slippage (in tables). Soil mass susceptible to movement 

downslope when loaded, excavated, or wet. 

Slope gradient. The inclination of the land surface from the 

horizontal. Percentage of slope is the vertical distance 

divided by horizontal distance, then multiplied by 100. 

Thus, a slope of 20 percent is a drop of 20 feet in 100 

feet of horizontal distance. 

Slope length. The distance from the origin of the overland 

flow to the point where the slope gradient decreases 

enough that deposition begins or the runoff water 

enters a well-defined channel. 

Stocking (woodland). The degree to which an area is 

effectively covered with living trees. It is expressed as a 

percentage of the basal area or crown closure relative 

to that of a normal stand. Well stocked is 70 to 100 

percent of a normal stand; medium stocked is 40 to 70

percent; poorly stocked is 10 to 40 percent; nonstocked 

is less than 10 percent; and overstocked is more than 

100 percent. 

Stones. Rock fragments 10 to 24 inches (25 to 60 

centimeters) in diameter. 

Stripcropping. Growing crops in a systematic 

arrangement of strips or bands to reduce erosion. The 

crops are arranged so that a protective strip of 
grass or a close-growing crop is alternated with a strip 

of a clean-tilled crop or fallow. Contour strips follow the 

contour of the slope and are designed to reduce sheet 

and rill erosion and control water. Field strips are 

placed across the slope to reduce sheet and rill erosion. 

Wind strips are arranged at angles generally 

perpendicular to erosive winds to control soil blowing, 

trap snow, and increase the soil moisture content. 

Structure, soil. The arrangement of primary soil particles into 

compound particles or aggregates. The principal forms 

of soil structure are platy (laminated), prismatic (vertical 

axis of aggregates longer than horizontal), columnar 

(prisms with rounded tops), blocky (angular or 

subangular), and granular. Structureless soils are either 

single grained (each grain by itself, as in dune sand) or 

massive (±he particles adhering without any regular 

cleavage, as in many hardpans). 

Stubble mulch. Residue of small grain left on the surface of 

the soil. It protects the soil from wind and water erosion 

after harvest, during preparation of a seedbed for the 

next crop, and during the early growing period of the 

new crop. 

Subsoil. Technically, the B horizon; roughly, the part of the 

solum below plow depth. 

Subsoiling. Loosening the soil without inverting it and with a 

minimum of mixing of the surface layer to shatter 

restrictive layers (at a depth of more than 16 inches) 

that inhibit water movement or root development. 

Substratum. The part of the soil below the solum. 

Suitable surfacing (logging roads). Rock of adequate 

hardness and size used to cover a road so that it can 

withstand repeated and long-term logging truck traffic. 

Surface layer. The soil ordinarily moved in tillage, or its 

equivalent in uncultivated soil, ranging in depth from 4 to 

10 inches (10 to 25 centimeters). Frequently designated 

as the "plow layer," or the "Ap horizon." 

Terrace. An earth embankment, channel or ridge and 

channel constructed across the slope (gradient terrace) 

or on the contour (level terrace) to (1) reduce slope 

length, (2) reduce erosion, (3) reduce the content of 

sediment in runoff water, (4) intercept and conduct 

surface runoff to a stable outlet, (5) retain runoff for 

moisture conservation, (6) prevent development of 

gullies, (7) reform the land surface, 

(8) improve the soil for farming, and (9) reduce 

flooding. 

 Terrace (geologic). An old alluvial plain, ordinarily flat or 

undulating, bordering a river, a lake, or the sea. 

Texture, soil. The relative proportions of sand, silt, and clay 

particles in a mass of soil. The basic textural classes, in 

order of increasing proportion of fine particles, are sand, 

loamy sand, sandy loam, loam, silt loam, silt, sandy clay 

loam, clay loam, silty clay loam, sandy clay, silty clay, 

and clay. The sand, loamy sand, and sandy loam classes 

may be further divided by specifying "coarse," "fine," or 

"very fine." 

Topsoil. The upper part of the soil, which is the most 

favorable material for plant growth. It is ordinarily rich 

in organic matter and is used to topdress roadbanks, 

lawns, and land affected by mining. 

Upland (geology). Land at a higher elevation, in general, 

than bottom land or terraces. 

Variant, soil. A soil having properties sufficiently different 

from those of other known soils to justify a new series 

name, but occurring in such a limited geographic area 

that creation of a new series is not justified. 

Water bar. A smooth, shallow ditch or depressional area 

that is excavated at an angle across a sloping road. It is 

used to reduce the downward velocity of water and to 

divert the water off and away from the road surface. 

Water bars can easily be driven over is constructed 

properly. 

Weathering. All physical and chemical changes produced 

in rocks or other deposits at or near the earth's 

surface by atmospheric agents. These changes result 

in disintegration and decomposition of the material. 

Wilting point (or permanent wilting point). The moisture 

content of soil, on an ovendry basis, at which a plant 

(specifically sunflower) wilts so much that it does not 

recover when placed in a humid, dark chamber. 

Windthrow. The action of uprooting and tipping over 

trees by the wind. 

Yarding path. The path left by cable-yarded logs as they 

are pulled uphill or downhill to a nearby, central area. 

Yield table, normal (woodland). Table showing the number 

and size of trees, total basal area, and yield per acre. 

These tables commonly are for even-aged, unmanaged 

stands. Values are given for stands at different ages on 

sites of different quality. 

Yield (woodland). The volume of wood fiber from trees 

harvested from a certain area. Yield commonly is 

measured in board feet or cubic feet per acre.