Botanical Evidence of 

the Modern History of 

Nisqually Glacier 

Washington

GEOLOGICAL SURVEY PROFESSIONAL PAPER 387-A
Botanical Evidence of 

the Modern History of 

Nisqually Glacier 

Washington

By ROBERT S. SIGAFOOS and E. L. HENDRICKS

BOTANICAL EVIDENCE OF GLACIER ACTIVITY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 387-A

A description of botanical methods used to determine dates of recession of three glaciers at Mount 

Rainier, Washington

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.
CONTENTS

Abstract.__________________________________________

Introduction __-__-_________-_---_---_-_-_-_-_-__-__

Area of study _ _____________________________________

Methods of study___________________________________

Topographic and botanical evidence of surface age__ 

Growth increments of trees______________________

Age sampling and mapping plan. _________________

Appearance of the forest-____________________

Old forest-___--_________-_-____-_--____

Young forest.__________________________

Selection of trees.__________________________

Geographic distribution of key trees and age 

groups.__________________________________

Modern history of Nisqually Glacier _ _________________

Maximum advance in last thousand years____-_-___

Botanical evidence._________________________

Pyroclastics and humus sequence. ____________

Page 

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Modern history of Nisqually Glacier Continued

Recession between 1840 and 1900_________________ A-l 1

Location and description of moraine.__________ 11

Time interval between cessation of advance afld

establishment of seedlings._________________ 11

Maximum age of young forest..-------------- 14

Dates and early rates of recession _____________ 15

Reconnaissance study of moraines of Emmons and

Tahoma Glaciers-_-_-__-___-____--___----_---____ 16

Moraines of Emmons Glacier.____________________ 16

Moraines of Tahoma Glacier-____________________ 18

Summary and conclusions____-------_--____-_________ 19

References cited____________________________________ 20

ILLUSTRATIONS

Page

FIGURE 1. Index map of Mount Rainier National Park________._.__________________-_______-_------_-_---_--------- A-2

2. Moraine at the approximate position of Emmons Glacier terminus in 1910-13. _________

3. Forest of living trees, 300 years old, beyond the 1840 moraine of Nisqually Glacier,_____

4. Forest of young trees on the 1840 moraine of Nisqually Glacier-______________________

5. Diagrams showing possible relations between successive advances of a glacier_____-__-_-

6. Map of Nisqually Glacier terminal moraine and vicinity____________-,__--_---_-------

7. Nisqually River valley in the vicinity of 1840 moraine of Nisqually Glacier_____________

8. Right wall of the Nisqually River valley downstream from Tato Falls._______-_-_-----

9. Moraines of Emmons Glacier in the valley of White River and Inter Fork_ ____________

10. Sketch map of terminal moraines and of areas studied in the vicinity of Emmons Glacier11. Diagram showing ages of trees in 1959 and positions of the terminus of Emmons Glacier_

12. Map of Nisqually Glacier showing the 1840 moraine and vicinity. ____________________

13. Two Douglas-fir trees down valley from the 1745 moraine of Emmons Glacier.- _________

14. Generalized profile across the moraines of Emmons Glacier_______________-----_-----_

15. Old forest and two moraines downvalley from Tahoma Glacier_______________-____---_

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BOTANICAL EVIDENCE OF GLACIER ACTIVITY

BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER, WASHINGTON

By ROBERT S. SIGAFOOS and E. L. HENDRICKS

ABSTRACT

A knowledge of the areas once occupied by mountain glaciers 

reveals at least part of the past behavior of these glaciers. 

From this behavior, inferences of past climate can be drawn. 

The maximum advance of Nisqually Glacier in the last 

thousand years was located, and retreat from this point is 

believed to have started about 1840. The maximum dawnvalley position of the glacier is marked by either a prominent 

moraine or by a line of difference between stands of trees of 

strikingly different size andi significantly different age. The 

thousand-year age of the forest beyond the moraine or line 

between abutting stands represents the minimum time since 

the surface was glaciated. This age is based on the age of 

the oldest trees, plus an estimated interval required for the 

formation of humus, plus evidence of an ancient fire, plus an 

interval of deposition of pyroclastics. The estimate of the 

date when Nisqually Glacier began to retreat from its maximum 

advance is based upon the ages of the oldest trees plus an interval of 5 years estimated as the time required for the 

establishment of trees on stable moraines. This interval was 

derived from a study of the ages of trees growing at locations 

of known past positions of the glacier.

Reconnaissance studies were made on moraines formed by 

Enimons and Tahoma Glaciers. Preliminary analyses of these 

data suggest that Emmons Glacier started to recede from its 

maximum advance in about 1745. Two other upvalley moraines 

mark positions from which recession started about 1849 and 

1896. Ages of trees near Tahoma Glacier indicate that it 

started to recede from its position of maximum advance in 

about 1635. About 1835 Tahouia Glacier started to recede 

again from another moraine formed by a readvance that terminated near the 1635 position.

INTRODUCTION

A common problem in hydrology is that of determining where modern water-supply data fit into the 

long-term pattern of fluctuating water supplies. 

Streamflow and other water records are too short a 

base from which to extrapolate most long-range waterdevelopment plans. Therefore, water-resources investigators have sought, from time to time, to 

reconstruct past climatic trends by interpreting the 

physical evidence left by modern hydrologic events.

This study of the recent moraines of Nisqually Glacier, Mount Rainier, Wash., is one of the efforts

to reconstruct past climatic trends. The hypothesis is 

simple: Glaciers advance and retreat in a manner somehow related to climate; therefore, if something is 

known of a glacier's movement in the past, some kind 

of crude inferences about the climate existing at the 

time of movement may be drawn. A larger study, of 

which the study of Nisqually Glacier is a part, is concerned with dating the terminal positions of several 

glaciers on Mount Rainier at several times hi recent 

history when points of maximum advance were reached. 

Furthermore, because the present study is based on the 

ages of trees adjacent to the glaciers, only glacial advances during the last 1,000 years or less are being investigated. This report is concerned primarily with 

Nisqually Glacier but includes a brief discussion of a 

reconnaissance study of moraines formed by Emmons 

and Tahoma Glaciers. It is the first report of a series 

on the broader study.

Acknowledgment is made for the great assistance 

offered by the staff of Mount Rainier National Park, 

especially by V. R. Bender, chief naturalist. The 

writers benefited from discussions in the field and office 

with Arthur Johnson, D. R. Crandell, R. D. Miller, and 

D. R. Mullineaux of the U.S. Geological Survey. 

Arthur Johnson first interested the authors in the 

study, and he kindly compiled a planetable map of 

part of Nisqually Glacier terminal moraine especially 

for this report. Ethel W. Coffay of the U.S. Geological Survey provided considerable help in the study of 

core samples.

AREA OF STUDY

Nisqually Glacier, on the south slope of Mount 

Rainier, was chosen as the initial subject for study because of the large volume of data on its terminal positions during the last 60 years (Bender and Haines, 

1955, p. 275-280). Also, it is the most accessible glacier 

and is part of the largest single-peak system in the 

conterminous United States. The recorded positions 

of the terminus together with the ages of trees at these

A-l
A-2 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

positions provide data for use in interpreting tree 

ages as a means of dating the ice positions marked by 

moraines deposited before detailed observations began. 

In addition, a reconnaissance was made of both Emmons and Tahoma Glaciers to determine whether 

botanical evidence shows their history to be similar 

to that of Nisqually Glacier.

122°00'

47°00'

121°45'

Nisqually, Emmons, and Tahoma Glaciers are valley 

glaciers that radiate from the central ice cap of Mount 

Rainier. Nisqually Glacier extends down the south 

side of the mountain, Emmons down the northeast 

side, and Tahoma down the southwest side (fig. 1). 

The present terminus of Nisqually Glacier is at an 

altitude of about 4,500 feet, the terminus of Emmons

121°30'

46°45'

MOUNT RAINIER

Emmonf 

Mt Rainier Glaciers

Nisqually 

Glacier; 

\ J

NATION AlL

5 MILES

FIGURE 1. Index map of Mount Rainier National Park, Wash.

Glacier is at about 5,300 feet, and that of Tahoma 

Glacier is somewhat higher, possibly at about 5,600 

feet. The valleys are U-shaped with steep sides that 

are nearly vertical at several places. At other places 

slopes are so steep that perennial rock slides and snow 

avalanches are common. Trees grow in profusion 

where the valley slopes are gentler.

The flood plains immediately downvalley from existing glaciers are largely the products of streams that 

now occupy the valleys. Nisqually River emerges 

from an ice cave in the terminus of Nisqually Glacier. 

White River originates at a few points along the 

broader terminus of Emmons Glacier. South Puyallup 

River, which flows from Tahoma Glacier, was not examined in much detail during the short reconnaissance.

Nisqually and White Rivers meander over boulderstrewn flood plains built up largely from debris deposited by glaciers, floods, and mudflows. Floods, like 

the one of October 25, 1955 on Nisqually River within 

the park boundary, consist of surges of water released 

at the snout of Nisqually Glacier following exceptionally heavy rain. This flood roared down the steep 

valley at a high velocity carrying a large amount of 

bedload material that included boulders more than 6 

feet in diameter. The highway bridge, a short distance 

below the glacier was swept away, as were previous 

bridges at the same location. The volume of water 

over the flood plain was so great for about 4 miles 

downstream from the glacier that virtually all vegetation was either buried or swept away in this reach.
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-3

For the greater part of the summer season, however, 

the main streams and small tributaries entering below 

the glaciers' termini derive their water from melting 

snow and ice. As would be expected the rate of flow 

fluctuates diuriially in direct response to the heat available for melting and to the area of exposed ice and 

snow. Owing to the steep longitudinal gradients of 

the valleys, much energy is available in melt water for 

the movement of flood-plain gravel and boulders. These 

streams at all times, and especially during periods of 

high flow, are working and reworking the flood-plain 

sediments by the constant migration of meanders from 

one side of the valley to the other.

As a result of lateral migration and flooding, vegetation on the flood plains stands little or no chance of 

growing old. Thus, in order to find both topographic 

and botanical evidence of past glacier positions, this 

study is limited to the vegetation growing on the 

valley sides.

Below an altitude of about 5,000 feet the vegetation 

on these side slopes, where not destroyed by recent 

floods, consists of a dense forest of coniferous trees 

(Brockman, 1949, p. 3-6). Above 6,500 feet, the country 

is treeless, and the ground is covered with alpine 

meadow vegetation or is bare. Between 5,000 and 

6,500 feet, the forest is open and parklike. Thus the 

modern terminal moraines and present termini of glaciers (p. A-ll) are below the upper timberline. This 

fact permits the use of botanical methods in dating 

surfaces once occupied by glaciers.

The old forest on slopes above and beyond the trimline in the vicinity of Nisqually, Emmons, and Tahoma 

Glaciers consists primarily of western white pine, western hemlock, Douglas-fir, Pacific silver fir, noble fir, 

and Alaska-cedar. Trimline is a term suggested by 

K. P. Sharp, according to Lawrence (1948, p. 26), to 

designate a boundary between types of vegetation differing in age of plants, in species, or in the density of the 

stand marking a position from which a valley glacier 

has recently receded. Lodgepole pine and Engelman 

spruce are common on the modern moraines of Emmons 

Glacier. Whitebark pine grows on the moraines of 

Tahoma Glacier. Sitka alder forms dense thickets in 

places on the younger morainic surfaces where coniferous trees are small and widely scattered. Vine maple 

and Douglas maple grow in the forest and form dense 

thickets in most open areas within the forest. Black 

cottonwood trees are scattered along some of the streams. 

A complete list of common and Latin names is given 

in table 1; these names are the ones used by Little 

(1953).

Common name

Alaska-cedar__.

Bigleaf maple_______

Black cottonwood_ 

Douglas-fir__________

Engelmann spruce___ 

Lodgepole pine______

Noble fir____________

Pacific silver fir_____

Red alder__________

Sitka alder_________

Vine maple____. . 

Western hemlock____

Western redcedar___ 

Western white pine. 

Whitebark pine_____

List of species

Latin name 

Chamaecyparis nootkatensis (D. Don)

Spach

Acer macrophyllum Pursh 

Populus trichocarpa Torrey and Gray 

Pseudotsuga menziesii (Mirb.) Franco 

Picea engelmanmii Parry 

Pinus contorta Douglas 

AMes procera Render

amaMUs (Douglas) Forbes 

Alnus rubra Bongard 

Alnus sinuata (Regel) Rydberg 

Acer circinatum Pursh 

Tsuffa heterophylla (Rafinesque) Sargent 

Thuja plicata Donn 

Pinus monticola Douglas

albicaulis Engelmann

METHODS OF STUDY

TOPOGRAPHIC AND BOTANICAL EVIDENCE OF 

SURFACE AGE

In this study two kinds of evidence of recent positions of the ice front were used: Topographic and 

botanical. The maximum downvalley position reached 

by a glacier in a period of advance may be marked by 

a prominent ridge of rock debris, a terminal moraine. 

Positions at which the glacier terminus halted for an 

appreciable time during a period of recession also may 

be marked by a ridge, a recessional moraine (fig. 2). 

All such positions, however, are not marked by debris, 

because the glacier may not have carried a sufficient 

load or may not have remained in a given position long 

enough for a moraine to form. At some locations in 

the valley, the slopes may be so steep and unstable that 

previously existing moraines have been removed by 

erosion.

Where topographic evidence for the recent ice position is absent or masked, the position is marked by a 

line of sharp difference in age between forests. As a 

glacier advances it destroys all trees in its path. As 

a glacier recedes it leaves a trimline between the preexisting forest beyond its margin and the fresh glacial 

debris on its bed. After the glacier's recession, trees 

again begin to grow on the scoured areas and, in time, 

a forest becomes well established. However, the location of the old ice margin remains clearly delimited 

by the difference in size and age of the adjacent forests.

The primary method of dating a historical ice position used here consisted of studying adjacent forests 

of different ages. Where moraines exist they were 

used as evidence of an ice position. The age of a tree 

is interpreted to be the minimum period that has elapsed 

since the ice left the position occupied by the tree. In 

order to establish a minimum age of a given surface, 

an attempt is made to determine the age of the oldest 

tree on that surface.
A-4 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

In order to explain the significance of the ages of 

trees found on moraines in terms of the regimen of 

glaciers, a brief description of glacier shrinkage may be 

helpful. Glaciers shrink in two different ways, each 

resulting in a particular topographic expression 

(Sharp, 1951b, p. 108-109). The terminus of a receding 

glacier is distinct and may be relatively free of surface 

debris, because the ice in the terminus is moving forward while the leading edge is receding. The terminus 

of a stagnant glacier is quite different, because a larger 

loss in volume results from vertical shrinkage than 

from terminal recession. Consequently, the leading 

edge and surface are covered with superglacial debris 

derived from englacial material and from avalanched 

material from the valley walls. The chaotic surface 

of the glacier in the zone of stagnation consists of 

knobs and ridges separating ponds and streams. The 

decayed condition of the ice is further indicated by 

numerous arches, caverns, and tunnels. Such a stagnant reach results from the ice becoming too thin to 

show appreciable motion.

The superglacial debris oil a stagnant glacier, 

ranging from clay-sized particles to large angular 

blocks (Sharp, 1949, p. 294), is subject to extensive 

reworking as the underlying ice melts, causing the 

overlying debris to slump. The finer fractions in the 

debris are partly removed by superglacial streams. 

However, modification of the superglacial features decreases as the amount of debris increases relative to the 

amount of ice (Sharp, 1949, p. 295-312).

Trees become established on superglacial debris that 

is not completely stabilized or that overlies a slowly 

moving glacier (Matthes and Phillips, 1943, p. 18-19, 

23). Trees as old as 100 years grow on thick superglacial deposits on Malaspina Glacier (Sharp, 1951a, 

p. 726). Trees ranging from 1 to 3 feet tall and from 

47 to 56 years old were found growing on an ice-cored 

moraine at the approximate position of Emmons Glacier terminus in 1910-13 (fig. 2) as represented on the 

quadrangle map of Mount Rainier National Park. Although seedlings start to grow on superglacial debris 

on moving glaciers, most of them are believed to survive only after debris ceases to collapse repeatedly.

The age of the oldest tree at a given place, therefore, is equivalent to the time that has elapsed since the 

glacial debris upon which the tree is growing became 

stable enough for seedlings to survive. The time required for superglacial debris to accumulate and become stable along the margins of a glacier or on 

stagnant ice must be determined and added to the age 

of the oldest tree in order to estimate the length of 

time since cessation of active scouring. Determination

FIGURE 2. Moraine at the approximate position of Emmons Glacier 

terminus in 1910 13, as shown on map of Mount Rainier National 

Park. A stream that rises near Baker Point is in left background. 

Melting ice is present under the slumping moraine at right. Tree 

seedlings from 1 to 3 feet tall are numerous in this area.

of this interval is done by sampling trees and seedlings 

growing at known past positions of the glaciers.

The availability of tree seed is also of primary importance because it dictates which species become 

established and, along with the physical suitability of 

the seed bed, the rate at which the forest increases in 

density. The presence of seedlings on the youngest 

moraines of Emmons and Nisqually Glaciers formed 

in the last 10 years lends validity to the assumption 

that at least some seed is available in all years.

When the older modern moraines, such as those 

downvalley from Nisqually Glacier upon which the 

trees are less than 120 years old and those downvalley 

from Emmons Glacier upon which the trees are less 

than 210 years old, first became stabilized, they were 

much closer to a seed source than are the younger surfaces upon which trees are now starting to grow. Mature forast trees grew on surfaces adjoining and partly 

surrounding these older moraines (figs. 7, 9). Therefore, abundant quantities of tree seed were available 

and seedlings undoubtedly became established as soon 

as the morainic debris became stabilized.

Data are presented later (p. A-ll) to show that 

the period between the stabilization of the seed bed 

and the establishment of tree seedlings is only a few 

years. The short time interval illustrates the fact 

that the tree species that make up the mature forest 

are among the first plants to become established on 

new surfaces. Willow species, alder, and heaths form 

dense thickets in places; tree species are scattered. 

Thus the evidence discloses that growth of the shrubs, 

including alder, is coincident with the establishment of
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-5

tree species. Insufficient time between the formation 

of new surfaces and the start of tree seedlings rules 

out any sort of plant succession before the germination 

and growth of tree species that make up the mature 

forest. Any change in vegetation through time, which 

might be inferred from differences in vegetation 

on surfaces of different age, seems to be related to the 

death of shorter lived species and the continued growth 

of trees.

GROWTH INCREMENTS OF TREES

The oldest trees whose age is determined by counting 

the annual-growth rings, provide the basis for estimating the minimum age of the surface upon which they 

grow. These rings can be seen in a stump section or 

in a core sample removed from the trunk. The number 

of annual rings that can be counted in stumps is believed to be close to the true age of the trees, because 

nearly all stumps examined measured less than 6 inches 

high. Trees are probably older than the age indicated 

by core counts, because most cores were taken more 

than 12 inches above the ground, which is above the 

height of trees in the seedling stage. However, error 

from this source is negligible, because the ages determined from cores are comparable to those determined 

from stumps. In fact, the highest count of rings in a 

stump in a young forest was 112, whereas the highest 

count of a core in the same forest was 117.

The diameter growth of trees and the characteristics 

of wood, including the identification of annual rings 

are discussed by Brown, Panshin, and Forsaith (1949, 

p. 12-2T, 35, 52, 96-111, 126-163, 196-238), Eames 

and McDaniels (1947, p. 175-231), and Esau (1953, p. 

125-136,338-^11).

AGE SAMPLING AND MAPPING PLAN 

APPEARANCE OF THE FOREST

Several botanical characteristics are considered in the 

problem of seeking the oldest trees in several localities 

in order to date past ice positions. The gross appearance of a forest provides the primary means of 

making a broad estimate of the relative age of the surfaces upon which the forest grows (Lawrence, 1950). 

Just as a population of older people can be distinguished 

by sight from a population of younger people, so can 

an old forest be distinguished from a young forest. 

Within each area the ages of the oldest trees were 

estimated by their appearance before the trees were 

cored.

OLD FOREST

The largest trees in an area grow in the old forest, and 

at Mount Rainier most of them have trunks that range 

from 3 to 5 feet in diameter (fig. 3). A few trees are

584492 O 61 '2

FIGURE 3. Forest of living- trees, 300 years old, fallen logs,, and rotted 

stumps. Old surface is downvalley from 1840 terminal moraine of 

Nisqually Glacier. (See fig. 4.)

as large as 6 feet in diameter. Ancient trees bearing 

broken tops, open foliage, or branches only part way 

around the crown are characteristic. The forest floor 

is covered with fallen logs in all stages of decay, of 

which the soundest are of about the same diameter as 

the largest living trees. Seedlings and small trees grow 

on the still identifiable rotted logs.

Scattered through the forest are barely perceptible 

mounds and pits that may be the erosional remnants 

of soil mounds formed by the fall of ancestral trees. 

Such mounds are common in the deciduous forest of the 

eastern United States and persist for a long time 

(Shaler, 1892, p. 273-274; Lutz, 1940; Goodlett, 1954, 

p. 66-81; Denny and Goodlett, 1956, p. 59-66). Thick 

humus layers almost completely cover the forest floor 

except on the youngest mounds formed by uprooted 

trees and along banks of small streams.

Humus, as used in this report and oy foresters 

(Munns, 1950; Trimble and Lull, 1956, p. 2-8), is 

defined as the organic matter and intermixed mineral 

matter in soil profiles. It includes the partly decomposed surface litter in which plant parts can be recognized by sight. The humus consists of layers of rotten 

wood derived from old logs lying at all angles one on 

top of the other and differing in the degree of decay. 

The humus alone appears to represent a long interval 

of time. The largest living trees, whose ages can be 

estimated only from a count of annual rings found in 

a core of part of the radius, appear to represent only 

the most recent of several generations of trees.
A-6 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

Study of soil profiles reveals additional evidence of 

the antiquity of the forests on the old surfaces. Large 

fragments of charcoal and partly charred wood are 

found commonly beneath humus layers and close to the 

roots of the largest living trees. The charcoal is evidence that fire swept through an ancient forest that 

existed before the growth and death of the trees which 

rotted to form the humus and before the present forest 

began to grow. Volcanic ash layers, where present, are 

used to estimate the relative age of different surfaces.

YOUNG FOREST

The largest living trees in the young forests are 

smaller than the average size trees in the old forest 

and have well-formed crowns and dense foliage (fig. 

4). Fallen trees are present, but logs are smaller in

FIGURE 4. Forest of young trees, smaller logs, and nearly bare boulders near the downvalley limit of the 1840 terminal moraine of Nisqually Glacier; trees are 1 to 2 feet in diameter. (See fig. 3.)

diameter thtm the trunks of standing trees indicating 

that they were members of a more dense stand in its 

early stage of development. Humus layers generally 

are thin, consisting primarily of decayed leaf litter. 

Bare or nearly bare boulders protrude through the 

humus, and mineral soil can be exposed by merely 

scratching the humus.

The only evidence of earlier forest growth in soil 

profiles on the younger surfaces consists of humus 

which is being formed from litter from the living trees. 

All evidence indicates that the present forest is the 

first to grow; thus the age of the oldest trees nearly 

equals the time the surfaces have been exposed to plant 

colonization.

SELECTION OF TREES

Within each forest population, that is, within the 

old forest and within different age groups in the young 

forest, trees at many localities were selected for detailed 

study. In localities where moraines exist, trees on both 

sides of the moraine or close to the presumed historic 

position of the ice were chosen. They included the 

oldest tree in the population, whose age was determined 

in order to provide an estimate of the minimum age 

of the surface at the trees' location. Individual trees 

that appeared to be the oldest were selected for 

sampling.

Trees in the Mount Rainier area apparently reach 

a maximum diameter of 4 to 6 feet. Because of the 

relatively rapid growth rate, only about 300 years is 

required for trees in the Nisqually River valley to grow 

to this diameter. Near Emmons Glacier, on the other 

hand, more than 400 years are required for trees to 

reach the maximum size before they die. However, 

some trees near Nisqually Glacier are growing more 

slowly than any trees sampled near Emmons Glacier. 

Thus the maximum age of trees cannot by itself be used 

to determine the age of an old surface, and it is necessary to search for additional evidences of age. Furthermore, if the growth rate of trees in a given area is 

determined to be relatively rapid, then the chances are 

low of finding an individual significantly older than 

the average of those sampled. If, on the other hand, 

the growth rate is relatively slow, diligent search might 

disclose an ancient specimen that is significantly older 

than its neighbors.

The general appearance of the bark of trees is the 

best single criterion for estimating the relative age of 

several trees of the same species within a stand. Because the bark consists primarily of cork produced continuously during the growing season by a layer of 

living cells within the inner bark, the outer cells remain unaffected by growth, and thus the bark of older 

trees looks more weathered and eroded than the bark of 

younger trees.

Twisted and gnarled trees that have stems bent in 

several directions generally are older than larger trees 

which are more symmetrical. Close study of the branches of these bent trees shows small closely packed 

needles and exceedingly short annual increments of twig 

growth. These anual increments can be identified as 

the length of the twig between successive minute scars 

remaining from the abscission of the terminal-bud 

scales. These scars are closely spaced lines in the bark 

running normal to the axis of a twig. Exceedingly short 

annual increments of twig growth during recent years 

combined with a twisted form suggests that such trees 

have always grown slowly and thus may be of considerable age.
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-7

Because the diameter of the trunk is a function of the 

growth rate as well as of age, it is the poorest single 

criterion to use in selecting trees for a core sample. For 

example, three Pacific silver fir trees growing in the 

same area on a slope above the Nisqually River all are 

about the same age, but differ markedly in diameter as 

shown in the table below.

Tree

A

B _______

c

Diameter

(inches)

24

16

30

Age (years)

104

96

113

Annual radial

growth rate

(inches)

Ho

K2

1A

The largest tree within a given species was cored, 

but other trees which appeared to be older on the basis 

of the other criteria previously outlined, were also 

cored. If all trees within a group appeared to have 

nearly the same vigor, the largest of each species was 

cored.

Many trees must be sampled at many different sites 

in order to determine the age of the oldest tree in the 

forest, primarily because the mortality of individual 

trees is extremely high. A so-called good stand of 

established seedlings ranges from 500 to 1,000 seedlings 

per acre. Thus, where the oldest trees in any area of 

several acres number only one or two it is apparent that 

the mortality rate from seedling to maturity is extremely high. On many newly formed morainic surfaces there are far fewer than 500 to 1,000 seedlings 

per acre, yet the ages of the oldest trees on different 

parts of what appears to be a single moraine are remarkably similar. This demonstrates the effectiveness 

of the sampling procedure used in this study.

Because of the many environmental influences that 

lead to the destruction of trees at Mount Rainier, many 

trees were sampled at each place selected for study. 

Initially, in the life of a stand on the newly formed 

moraines, seedlings are subject to uprooting and burial 

on the unstable surfaces. Some slow-growing trees 

die in dense young stands in which most other trees 

are growing rapidly, probably because of excessive 

amount of shade. Rock and snow slides, insects, disease, 

and fire destroy individuals and large areas of forest. 

One or more of these influences have been of such magnitude and frequency in certain areas that trees in them 

were not used as samples in the present study.

In summary, many characteristics must be taken into 

consideration in selecting forest stands and individual 

trees for sampling to determine the maximum age of 

the forest. The appearance of individual trees, as 

well as the species and trunk diameters, is used to determine which individuals should be sampled once the 

stand is selected for study.

GEOGRAPHIC DISTRIBUTION OF KEY TREES AND 

AGE GROUPS

Experience in tracing the position of moraines 

quickly demonstrates that a given advance of a glacier 

does not necessarily follow the same pattern as its 

predecessor. Therefore, a younger and an older 

moraine may not necessarily parallel each other in all 

parts of the valley. In fact, such symmetry seems to 

be the exception. Thus it is necessary to obtain the ages 

of trees that grow within geographic bounds sufficiently 

extensive to cover virtually all parts of the valley.

The dissimilarity in the pattern of movement of two 

successive glacial advances may, for convenience, be 

classed as: those that are dissimilar because of a lateral 

shift in the axis of flow (fig. 5A} ; those that result from 

a difference in slope of the surface of the ice streams 

(fig. 5B) ; and those that differ because the last advance did not extend as far downvalley as an earlier 

one but that both follow the same axis of flow (fig. 5C]. 

In the class of two advances similar in downvalley extent and surface slope, but with lateral displacement 

of the axis of flow, the lateral moraine of the younger 

will show on one side of the valley, the lateral moraines 

of both the younger and the older will show on the other 

side of the valley, and the moraines will intersect somewhere near the terminal positions. In the class of two 

advances nearly similar in downvalley extent, but with 

differing longitudinal slopes, the lateral moraines of 

the younger or of both the younger and the older will 

be found on both valley sides, and the moraines will 

intersect at two places near the terminal positions.

In the third class of the last advance extending a 

shorter distance downvalley than an earlier one, the 

resulting moraines are roughly parallel and the younger 

ones occur within the older ones. Furthermore, a preexisting moraine tends to modify the course of a later 

advance, especially where the glacier moves through a 

breach in the older moraine.

In Nisqually River valley the most recent major advance overrode and obliterated all evidence of the moraines left by possible earlier, less extensive advances. 

This advance fits the class in which the terminal moraine and lateral moraines in the area studied are of 

the same age.

Limited observation of Emmons and Tahoma Glacier moraines indicate, however, that the existence of 

one class alone may be uncommon. Combinations of 

various degrees of each class produce a complex pattern 

of relationships between the positions of two glacial 

advances. A previous position of the glacier may be 

represented by only small widely separated segments.
A-8 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

FIGURE 5. Diagrams showing possible relations between successive 

advances of a glacier. Solid lines show position of moraines that 

remain after readvance. A. Similar in downvalley extent but with 

axes of flow displaced laterally; B. Closely similar in downvalley 

extent but differing in longitudinal gradient; C. Different downvalley extent but with same axis of flow.

Thus careful tree-age sampling on an extensive geographic pattern is required to correlate the identifiable 

ice-front positions. Although the complex pattern of 

ice-front positions adds to the sampling problem, it is 

also a fortunate circumstance in that the evidence of 

a larger number of glacier positions is more likely to 

exist than if the advances followed a simple pattern. 

The sequence of advances and recessions of Emmons

Glacier formed a complicated pattern of moraines, and 

studies to date are insufficient to unravel the complete 

history. At Tahoma Glacier, an older advance in the 

area studied is represented by a small segment of a 

lateral moraine that is bounded by a younger moraine.

MODERN HISTORY OF NISQUALLY GLACIER

Conspicuous remnants of a terminal moraine are located approximately 1 mile downvalley from the terminus of Nisqually Glacier (fig. 6) or about 800 feet 

downvalley from the bridge under construction in 

1958-60 on the highway between Longmire and Paradise. Lateral moraines extend upstream from the 

terminal moraine on both valley walls. These moraines 

mark the maximum advance of Nisqually Glacier during perhaps the last thousand years.

Field study was concentrated in the valley reach 

shown in figure 6. Thirty-two groups of trees in the 

entire study area were sampled. A total of 179 trees 

were cored, and annual rings were counted on 74 

stumps, cut in the winter of 1957-58 as a part of the 

new road construction. Annual rings on cores were 

counted in the field and recounted later in the laboratory. The location of the area and the location of some 

of the key trees are shown on figure 6.

MAXIMUM ADVANCE IN LAST THOUSAND YEARS

An old forest grows downstream from the terminal 

moraine and upslope from the lateral moraines. The 

age of this forest is a minimum estimate of the age of 

the drift-covered surface on which it grows. The appearance of the forest, the humus, and the soil profile, 

suggest that the surface is at least a thousand years old; 

probably it is much older.

BOTANICAL EVIDENCE

The living trees in this part of the Nisqually River 

valley range in size from 2 to 4 feet in diameter; some 

of the recently cut stumps in the old forest are as large 

as 6 feet in diameter. Annual ring counts of 21 of these 

older stumps were made, and the age of the trees at the 

end of their last growing season (1957) ranged from 

285 to 303 years. In addition, 23 trees in the old forest 

were cored, but the borer was long enough to obtain a 

sample of the entire radius from only 3 of them.

Throughout the old forest are many fallen logs and 

broken stumps (fig. 3). The wood in some of the 

logs is solid and appears to be sound; in others, the bark 

is intact and little decayed, but it conceals a punky, 

partly decayed trunk. Some logs are almost completely 

decayed and consist solely of rotten wood. Evidence 

of still older rotten logs can be found in places on the 

forest floor by digging in barely perceptible elongate 

ridges that are completely covered with mosses and
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-9

1956

1941

EXPLANATION

1956

O

Tree location and date of oldest 

annual ring

Ice margin 

Ice front

Base from U. S. Geological Survey Nisqually Glacier map, 

1951, 1956, Mt. Rainier National Park, Wash.

1000

I . , i , , , , ,

1000

1840 moraine

Located from aerial photographs by photogrammetric methods, dashed where 

inferred. Photographs taken 1956. 

Field check, 1958, 1959

Transect

2000 FEET

FIGURE 6. Map of Nisqually Glacier terminal moraine and vicinity showing the location of maximum modern advance and 

location and age of the key trees. Arthur Johnson and R. S. Sigafoos located trees, road, and 1840 moraine by 

plane table survey, August 30, 1958.

forest litter. The humus consists of layers of rotten 

wood in which the grain of the parent trunks is still 

apparent. A plane section through these layers cuts 

along and across the grain at all angles. This decayed 

wood almost completely carpets the forest and comprises 

the upper 0.5 to 1.0 foot of the soil profile. Because the 

sound and partly decayed logs are the same size as the

standing trees it is assumed that they were as old as 

the oldest standing trees, or about 300 years old when 

they fell. Although the mounds of rotten logs are 

considerably smaller than the sound fallen logs and 

standing trees, it is assumed that they, too, were about 

this old when they fell. The evidence, then, consists of 

living trees that are approximately 300 years old and
A-10 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

logs that are assumed also to have been 300 years old 

when they fell.

The different degrees of wood decay suggest that 

the falling of trees is a continuing thing and show, furthermore, that trees have fallen throughout a long 

period of time. Clear-cut evidence of the minimum 

amount of time that has elapsed since the death of 

the earliest generation of trees was not found. Evidence 

was found, however, that permits a rough estimate of 

the rate of wood decay in this area. The ages of two 

trees growing on the pit wall formed when a 4-foot 

noble fir was uprooted indicate that at least 50 years 

have elapsed since the tree fell. The wood in the fallen 

tree is sound. As will be discussed in more detail on 

page A-14, trees ranging in age from 111 to 117 years 

are growing on the Nisqually Glacier end moraine. Beneath the boulders comprising the moraine is an only 

partly decayed stump, 4 feet in diameter, which has 

been dead for at least 117 years. The partial decay in 

this length of time demonstrates that much time is required for logs to rot completely. In the Kautz Creek 

drainage basin, a western hemlock, 142 years old, was 

found growing on a fallen log of western redcedar 

in which the heart wood had the appearance of freshly 

cut lumber. These data, scanty though they are, indicate that at least 200 years was required to form the 

humus layers composed of decayed wood.

The fact that all fallen logs, whose original diameters 

still can be measured with accuracy, are similar in size 

to the 300-year old living trees, indicates that perhaps 

most of the rotten wood in the humus was formed from 

trees that were of this size and age when the fell. No 

evidence was found to suggest that any appreciable 

amount of the humus was formed by smaller trees. 

Therefore, if these two assumptions are valid, that at 

least 200 years was required for the wood to rot and 

the trees which fell were 300 years old, then these trees 

must have begun to grow at least 500 years ago,

A fire occurred before the death of the first trees, 

which are represented by the oldest humus. Evidence 

of this fire consists of large fragments of charcoal and 

charred wood, 2 to 5 inches in diameter and 8 to 12 

inches long, between the humus layers on the surface 

and mineral soil below. Measurement of the annualring curvature in two larger fragments shows that one 

has a radius of about 1 foot and the other about 1.5 

feet. These fragments came from logs with minimum 

diameters ranging from 2 to 3 feet, thus the minimum 

ages of the trees represented by these fragments ranges 

from 100 to 200 years. The fire required to char wood 

of this size probably destroyed all humus and killed 

the contemporary trees. Therefore, the fallen logs and 

humus layers postdate the fire which formed the charcoal. The charcoal represents an additional interval 

during which trees grew on the drift-covered surface. 

Thus, the botanical evidence, consisting of the age of 

living trees, fallen logs in all stages of decay, humus 

layers, and charcoal beneath the humus suggests that 

the subsurface has been forested for at least 600 to TOO 

years. This evidence is summarized as follows:

Total. -----

Age 

(years)

300

200

» 100-200

600-700

Thickness 

(feet)

0. 5-1. 0

0. 05-0. 15

Depth 

(feet)

0. 5-1. 0

Age determined byrate of decay.

diameter.

1 The result of a carbon-14 analysis of a wood sample (unit 2, p. A-ll, collected by 

R. D. Miller nearby at a level between the humus and the underlying pyroclastics 

was received subsequent to this study. The age is 1640±250 years Before Present 

(B.P.) (sample W-922, Rubin and Berthold, 1961).

These characteristics of old age are present in all 

parts of the old forest that were studied except on the 

southeast side of the valley. Here, a recent fire destroyed much of the evidence of the older forest. However, the presence of a few charred snags suggests 

that the forest downvalley from the moraine in this 

part of the valley is comparable in age to that on the 

northwest side. Charred logs found beneath the moraine boulders indicate that the fire, which largely 

destroyed the old forest, occurred before the last glacial advance which formed the end moraine.

PYROCIiASTICS AND HUMUS SEQUENCE

From available botanical evidence alone, extrapolation of the age of the surface upslope from the 1840 

moraine beyond 600 to 700 years is impossible. However, the material below the modern humus layer and 

charcoal suggests that more time, perhaps much more 

than 600 to 700 years, has elapsed since the surface 

beneath the old forest was last overridden by ice. The 

location of a section illustrating this is labeled pumice 

on figure 6, and the description (K. D. Miller, written 

communication, July, 1959) is given on page A-ll.

The following section does not provide a basis for 

an age estimate, because the ages of the ash falls are 

not yet known. The till, designated as unit 10, represents the last glaciation of the valley outside the 

1840 moraine. The essential question being discussed 

here is what length of time is represented by the pyroclastics, charcoal, humus, and living forest that now lie 

above the till. Arguments have been presented to 

support the conclusion that the present forest plus the 

preceding generations of trees represented by the rotten 

logs in the humus layer (unit 1) and charcoal (unit 2) 

represent a period of at least 600 to 700 years. The 

duff, or organic matter, units 4, 6, and 9, between
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-ll

Thickness 

Unit Material (feet)

1 Rotten logs; humus_____---_________-________ 0.5-1.0

2 Duff, 1 black_____________________________ . 05- . 15

3 Pumice, white, fine- to medium-sand-sized- _____ . 0 - . 3

4 Duff, black_________________________________ . 05-__-_

5 Pumice (?), reddish-brown, silty; fine-sand-sized

ash______________________________________ . 5 - . 7

6 Duff, black, fine- to medium-sand-sized; contains

charcoal._------__----_---_-----_--_______ . 0 - . 1

7 Pumice, white to light-gray, fine- to mediumsand-sized; silty in places; may be A2 of podsol 

soil; pumice grades from fine sand sized at top 

to coarse sand sized at base; grades into underlying pumice______________________________ . 3 - . 4

8 Pumice, yellow, coarse-sand-sized-_____________ . 9 -1. 0

9 Duff, dark-brown; overlies oxidized till; fills spaces

between boulders and cobbles at surface of till. _ . 2 - . 9 

10 Till, oxidized; wood fragments in upper part. ___ _________

Total thickness, units 1-9________________ 2. 50-4. 55

i Carbon 14 age is 1640±250 years B. P. See footnote p. A-10.

layers of pumice is evidence of still earlier forests and 

may easily represent several hundred years. If the 

organic matter and pumice layers represent only 300 

years, which seems to be a minimum, at least 900 to 

1,000 years have elapsed since the surface downvalley 

from the 1840 moraine was last glaciated.

Although detailed studies of the pyroclastic sequences 

in this area have not been made, the sketchy data indicate that the age of this surface is much older than one 

thousand years. For example, K. D. Miller and D. R. 

Crandell reported that the sequence found under the 

surface immediately downvalley from the 1840 moraine 

corresponds closely to one that they examined, located 

approximately 900 feet higher in altitude than the 

moraine (oral communication, July, 1959). The similarity of the pyroclastic sequences indicates that the 

age of the two surfaces is probably comparable and 

much older than one thousand years.

RECESSION BETWEEN 1840 AND 1900 

LOCATION AND DESCRIPTION OF MORAINE

The 1840 moraine of Nisqually Glacier is 10 to 20 

feet high, 25 to 50 feet wide, and is composed of angular 

blocks. The moraine is treeless at many places and thus 

forms an open lane between the old forest and the 

young forest.

Within the bounds of the 1840 moraine 22 areas were 

studied. The authors took cores from 104 trees and 

counted rings on 32 stumps. The location of the oldest 

trees in some of these areas is shown on the map in 

figure 6; the trees and the moraine in the vicinity of the 

highway were located by plane table. Other trees and 

moraines were located photogrammetrically from aerial 

photographs made in 1956.

The young forest within the bounds of the end 

moraine on each side of the valley occupies a crude 

wedge-shaped area, which narrows upstream (fig. 7). 

The forest extends approximately 1,000 feet upstream 

from the terminal moraine. The forest is only about 

100 feet wide at an altitude of about 4'JO feet above 

Nisqually River in the vicinity of the stream that forms 

Tato Falls on the northwest side of Nisqually River 

valley. The forest is somewhat wider on the southeast 

side of the valley in the vicinity of the stream opposite 

Tato Falls; its upper limit is about 600 feet in altitude 

above Nisqually River.

The trees in this forest consist of western white pine, 

western hemlock, Douglas-fir, Pacific silver fir, noble 

fir, and Alaska-cedar. They range in diameter from 

0.5 to 2.5 feet, hemlock and cedar trees are smaller than 

the others.

In contrast to the old forest, large fallen logs are 

not present in the young forest (figs. 3 and 4). Many 

trees have fallen, but trunks are smaller in diameter 

than those of the standing trees; thus the fallen logs are 

assumed to be of the same age or younger than, the 

standing trees. The forest floor consists predominantly 

of large boulders only partly overgrown by mosses and 

lichens. Little humus has accumulated, and it consists 

primarily of decayed litter. Almost no rotten wood is 

found in the humus indicating that too little time has 

elapsed since the moraine was formed for trees to grow, 

die, and decay. No charcoal is found in the soil profile 

from which a preexisting forest could be inferred.

TIME INTERVAL BETWEEN CESSATION OF ADVANCE 

AND ESTABLISHMENT OF SEEDLINGS

In order to determine the time interval between the 

accumulation and stabilization of superglacial debris 

during the final stages of advance of Nisqually Glacier, 

trees and seedlings were sampled at locations of known 

positions of the glacier in the past. Only a few seedlings were found immediately below the present position 

of Nisqually Glacier. Trees are growing, however, at 

places that are near older dated locations of the terminus of the glacier, and some seedlings are present on 

surfaces that are known to have been covered with ice 

during certain recent years. These trees started to 

grow from 2 to 13 years after ice was known to have 

covered the site. The dated positions of the ice front 

and year that the trees started to grow are shown in 

figure 6. Trees were sampled along a transect extending 

from Tato Falls about 350 feet northwest to a point 

at the edge of the dense forest. The location of this 

transect and of other sampled trees are shown on 

figure 8.
A-12 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

FIGURE 7. Nisqually Glacier is partly covered with snow at the head of Nisqually River valley near top of photograph; the 1840 moraine 

is indicated by a dashed line. Larger trees upslope from the line comprise the old forest; smaller trees downslope comprise the young 

forest. A new bridge (under construction) is visible in center; the older bridge is hidden by a fir tree in right foreground. July 9, 

 1959.

On the basis of data collected only in Nisqually Eiver 

valley, the time interval between stabilization of the 

moraine and establishment of seedlings averages about 

5 years. However, an analysis of tree ages on surfaces 

down valley from Emmons Glacier reveals that the time 

interval may be shorter. North of the stream flowing 

from Baker Point (figs. 9 and 10), two nearly bare 

moraines are located in the approximate position of 

Emmons Glacier in 1913, as represented on the quadrangle map of Mount Rainier National Park, 1955. On 

the moraine farther downvalley, trees started to grow 

between 1901 and 1904. On the other moraine, approximately 100 to 200 feet upvalley, the oldest tree sampled 

started to grow in 1903, four trees started to grow in 

1910, and one in 1912 (fig. 2). If the map of Mount 

Rainier National Park is accurate, then the glacier front

could not have been far from this position in 1913, so 

some of these trees must have been growing on a superglacial moraine when the map was compiled. Russell 

(1898, p. 396-397) reported that in 1896 the terminus 

was completely covered with morainic debris; and although he did not locate the front accurately, some of 

the trees sampled in this study probably started to grow 

on the moraine underlain by active ice. Stagnant ice 

was still present in 1959 under the moraines in this 

vicinity.

Tree seedlings become progressively younger on the 

younger surfaces in the White River valley upstream 

from the 1913 terminal position of Emmons Glacier. 

They are found only on surfaces 2 to 5 feet or more 

above the flood plain of White River, which is a braided 

stream that almost constantly reworks the flood-plain
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-13

FIGURE 8. Right wall of the Nisqually River valley between Tato Falls at right and the old highway bridge at left. Trees were cored along 

a transect from the right bank at the crest of the falls at the right diagonally to the left to the lower edge of dense forest. The 1885 

position is at the bridge on the left; the 1905 position located by LeConte (Arthur Johnson, oral communication) is halfway between Tato 

Falls and the stream to its left.

deposits during the summer. Sampling areas were 

located on these higher surfaces on the basis of known 

past locations of the ice front. At these areas the 

minimum time interval between the disappearance of 

the ice from a valley section and the establishment of 

tree, seedlings is estimated to range from 1 to 10 years. 

Thus data from the vicinity of Emmons Glacier, summarized in figure 11, indicate a shorter time interval 

than that estimated from data in the vicinity of Nisqually Glacier. However, there is no apparent basis 

for assuming that there is any inherent difference in the 

time required for establishment of seedlings at the two 

locations oi_ Mount Rainier. Data from both Emmoiis 

and Nisqually Glacier moraines indicate that tree seedlings become established early on exposed morainic 

surfaces.

Evidence from flooded areas also indicates that tree 

seedlings become established quickly on newly formed 

surfaces at Mount Rainier. A flood of considerable 

magnitude on October 25, 1955, destroyed parts of the 

forest on the bank of Nisqually River within Mount 

Rainier National Park. Seedlings of the same coniferous species that grow in the adjoining forest started 

to grow 1 to 2 years after the flood in fine material deposited or exposed by the flood. Kautz Creek, which 

drains Kautz Glacier and a small basin tributary to 

Nisqually River, was the locale of a mudflow on October

2,1947, which destroyed a large area of forest along its 

lower reach. Sand, gravel, and boulders were deposited 

to a depth of as much as 30 feet in an area approximately 

2,000 feet wide, resulting in the death of almost all 

trees in the area of deposition. Seedlings, of the same 

species as the trees that were killed and that make up 

the surrounding forest, started to grow on the new surface, 1 to 5 years after the mudflow.

The time interval between the formation of a new 

surface by a flood or mudflow and the establishment of 

tree seedlings is probably shorter than the interval between the melting of a glacier and germination of seedlings on the moraines. Surfaces affected by floods and 

mudflows probably become stabilized almost immediately. Data on the age of the trees growing on these 

surfaces indicate that seedlings may become established 

within a year.

Available evidence indicates that the time interval 

between the disappearance of the ice front from a 

valley section and the establishment of tree seedlings 

generally ranges from 1 to 16 years. This interval 

was probably less than 5 years but the authors conclude that the use of an average interval of 5 years 

is reasonable and is substantiated by their observations. 

As pointed out by Russell (1898, p. 407) in an area 

such as Mount Rainier where the environment is so
A-14 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

FIGURE 9. Moraines of Emmons Glacier in the valley of White River and Inter Fork. Emmons Glacier is visible upstream to left of area 22. 

Baker Point is the prominent ^now-covered ridge at top left. Numbered points indicate the approximate locations of areas studied. July 

18, 1959.

favorable to tree growth, trees soon become established 

on surfaces where fine soil has accumulated.

Five years is considerably shorter than the 30-, 35-, 

and 50-year intervals which Harrison (1956, p. 681- 

682) used to estimate the age of moraines at Nisqually 

Glacier. The 35-year interval is based on the age of 

trees growing upvalley from the position of the ice 

front in 1885, as located by Longmire (Meany, 1916). 

These trees are shown in left and center of figure 8 

between the trail and the base of the cliff. Harrison's 

estimate is based on incomplete data, because the authors found one tree that started to grow in 1890 in 

an area that probably had been covered with ice in 1885 

and two other trees that started to grow side by side 

in 1908 and 1912, approximately 600 feet upvalley. 

These trees indicate maximum intervals ranging from 

5 to 23 years. Ice undoubtedly did not disappear 

from the site of the trees that started to grow in

1908 and 1912 until long after 1885, thus the interval 

was much shorter than 23 years.

MAXIMUM AGE OF YOUNG FOREST

Trees were sampled in the young forest in seven 

areas near or on the terminal and lateral moraines in 

order to determine the date when the surfaces became 

stable. The oldest trees sampled ranged from 111 to 

117 years in age. Their location and ages are shown 

on the map (fig. 6) and indicate that they started to 

grow on one contiguous moraine at about the same time. 

If 5 years is added to these ages, the moraine has been 

stable for an estimated period ranging from 116 to 122 

years, indicating that Nisqually Glacier stopped its 

maximum modern advance between 1832 and 1843. 

Inasmuch as 1840 is 2 years before the germination of 

the 117-year old tree this moraine, for convenience, is 

called the 1840 moraine.
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQTJALLY GLACIER A-15

FORK

1958

Glacier margin

FIGURE 10. Sketch map of terminal moraines and of areas studied in 

vicinity of Emmons Glacier.

Study area

Age of oldest tree in 

1959

Time interval between 

recession and establishment

Position of terminus in 

specified year

Distance from 1958 

terminal position, in 

feet

21 20 19 18 17 16 15 14 13 

III II I I I I

10 9 14 15 20 25 19 16 57 58

III II I I I I I

6 5-10 5 5 25± 30± 6

I I I

II I I I I I

1940 A 1935 A 1930 A ,1 A

I I

1913 1896(?)

FIGURE 11. Diagram showing ages of trees in 1959 and positions of 

the terminus of Emmons Glacier.

Although the maximum advance of the glacier downvalley marked by the 1840 moraine cannot be located 

because the moraine is not continuous across the valley, 

a small stand of trees on the flood plain approximately 

2,000 feet downvalley from the older highway bridge 

marks a point beyond which the glacier could not have 

extended. The maximum advance of the ice front as 

estimated by projection of the lines representing the moraines is 500 feet upvalley from the oldest tree on the 

island. Most trees in this group died as a result of 

deposition during the 1955 flood (Arthur Johnson, 

oral communication) but a few are still living. An 

incomplete core from a Douglas-fir, 22 inches in diameter, showed 124 annual rings. The appearance of the 

innermost rings of the sound core and the fact that 

the core was taken well above the height of the first 

year's growth indicate that as many as 15 rings are 

missing, which would mean that the tree is at least 

about 140 years old. The mere fact that the tree is

older thai 124 years, which is 7 years older than the 

oldest tree found on the moraine, indicates that Nisqually Glacier could not haA^e advanced this far downvalley during its maximum modern advance. These 

trees are young and not as old as those in the forest 

on the valley-side slopes because trees growing on the 

flood plain along streams are killed by occassional catastrophic floods.

DATES AND EARLY RATES OF RECESSION

Lt. A. V. Kautz observed the front of the Nisqually 

Glacier in 1857 and located it at a "rock throat" 

(Brockman, 1938, p. 769-770; Giles and Colbert, 1955, 

p. 4; Meany, 1916, p. 82-83). This rock throat is a 

valley constriction at an outcrop generally considered 

to be 760 feet downstream from the old highway 

bridge. One tree on the north side of the valley, 

which started to grow in 1858, and another on the 

south side of the valley, which started to grow in 

1855, mark the maximum downvalley extent of Nisqually Glacier when Kautz saw it. The tree on the 

north side is approximately 200 feet from the old 

bridge, the other tree is approximately 400 feet. The 

location of these trees is shown (fig. 12) along with 

two possible locations of the ice front. One line extends across the channel about 760 feet from the old

EXPLANATION

1858®

Location and year tree 

started to grow

1840 moraine

500 FEET

Possible 1857 ice front 

positions

FIGURE 12. Map of Nisqually Glacier showing the 1840 moraine and 

vicinity, and possible positions of the ice front in 1857 and location 

of key trees. Arthur Johnson located trees by planetable survey, 

August 30. 1958.
A-16 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

bridge and the other about 450 feet. The glacier front 

probably was located somewhere between these lines.

When seen by Ixmgmire in 1885 (Meany, 1916), the 

ice front could not have been farther downvalley than a 

tree that started to grow in 1874. Five years later the 

front must have been farther upvalley than the location of a tree that started to grow in 1890 (fig. 12).

The data indicate that Msqually Glacier has been 

receding since about 1840. The data also reflect a variable rate of recession but do not indicate fluctuations 

because during the period of general recession minor 

advances may have occurred as is suggested by small 

morainic ridges upvalley from the 1840 moraine. 

Neither the readvances nor their dates of occurrence can 

be determined from the available botanical evidence.

RECONNAISSANCE STUDY OF MORAINES OF EMMONS 

AND TAHOMA GLACIERS

Reconnaissance studies were made in the vicinity of 

Emmoiis and Tahoma Glaciers in the summer of 1959. 

These glaciers had histories somewThat different from 

each other and different from Nisqually Glacier, so a 

brief summary of them is presented in this report. A 

more complete study of the age of the modern morainic 

surfaces here as well as those in the vicinity of some 

other glaciers at Mount Rainier is in progress.

MORAINES OF EMMONS GLACIER

Emmons Glacier is located on the northeast side of 

Mount Rainier at the head of White River (fig. 1). 

The terminus in 1958 (R. K. Fahnestock, written communication) was approximately 6,000 feet upstream 

from its location in 1910-13 as shown on the quadrangle map of Mount Rainier National Park. Downvalley from the 1910-13 location for about a quarter 

of a mile, three prominent moraines extend across a 

neck of land between White River and Inter Fork 

(fig. 9). The area and approximate location of the line 

along which the trees were cored are shown on figure 10.

A prominent terminal moraine that extends across 

the neck of land approximately half a mile upstream 

from the confluence of Inter Fork and White River 

marks the maximum advance of Emmons Glacier in at 

least a thousand years. Ages of the trees in the forest 

on the slope downvalley from the moraine cover a considerable range. Because a complete core could not be 

obtained from the oldest trees, the maximum age of 

these trees was not determined. Two old trees were 

determined to be 411 and 419 years old (fig. 13). The 

largest count, 694 annual rings, was obtained from a 15- 

inch core from a tree having a 16-inch radius. This 

tree is more than 700 years old. A count of 408 rings 

was obtained from a 7.9-inch core of a trunk having a

38-inch diameter exclusive of the bark. These trees 

are located about 300 feet downvalley from the toe 

of the moraine and signify that Emmons Glacier could 

not have occupied their present sites within at least the 

last 700 years. They are located in areas 3, 4a, and 5 

(figs. 9, 10, and 14). The presence of fallen logs of the

FIGURE 13. Two Douglas-fir trees, 411 and 419 years old, in the old 

forest downvalley from the 1745 moraine of Emmons Glacier. (See 

area 3, figs. 9, 10, and 14.)

same diameter as the 400- to 700-year-old living trees 

and humus layers composed of rotten wood of ancestral 

trees indicates that the surface is at least 300 years 

older than the oldest tree.

The time interval between the start of recession and

the establishment of seedlings on the moraines of

Emmons Glacier is believed to average about 5 years.

This estimate is based on a study of the ages of trees

that grow in the transect across surfaces that were

known to have been recently covered by Emmons

Glacier and that have been previously discussed on

pages A-12 and -13.

The oldest tree found growing on the terminal moraine is a 210-year-old Douglas-fir at the north end 

near Inter Fork (area 2, figs. 9 and 10). In the center 

of the moraine and at the south end, the oldest trees 

cored are 175 years old (areas 6 and 7, figs. 9,10, and 14). 

These trees started to grow in 1749 and 1784. The terminus probably started to recede about 1745, but the 

surfaces at the south end of the moraine may have remained untable for almost 30 years. Melt water from 

the receding glacier may have flowed over this part of 

the moraine and destroyed any seedlings that were 

temporarily established. After a period of 35 to 40 

years, however, the front probably had receded to a 

point sufficiently removed from the moraine so that melt 

water no longer flowed over it and the trees now 175 

years old started to grow.
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER 

Glacier, 1910-13_____

Recessional moraines

A-17

Terminal moraine

'Bare" moraines V

Study areas - + 13 + 11

+9

Annual rings counted 

Germination year, A. D. 

Start of recession, A. D.

57

1902

58 80 90

1901 1879 1869

105

1854

157

1802

175 175 265 408 ' 694 

210 187 419

1784

1897 1896 1874 1864 1849 1797 1779 

FIGURE 14. Generalized profile across the moraines of Emmons Glacier.

1749

1745

1540 1265

A small ridge (area 8, figs. 9,10, and 14) was formed 

inside the terminal moraine during the recession of 

Emmons Glacier. The oldest trees on it started to 

grow in 1802 suggesting that ice receded from here 

in 1797. Another prominent morainic ridge is located 

about halfway between the 1745 moraine and the approximate location of the ice front in 1910-13 (area 

9, figs. 9, 10, and 14). The oldest trees on it started 

to grow in 1854, suggesting that recession started from 

here about 1849. This moraine may have been formed 

by an advance which was virtually contemporaneous 

with the maximum advance of Msqually Glacier.

A fourth moraine (area 11, figs. 9, 10, and 14) is 

located a short distance downvalley from the 1910-13 

location of the ice front but was formed earlier. The 

oldest trees on it started to grow in 1901. The ice 

could have been at this moraine in 1896 at the time 

Willis, Eussell, and Smith made field studies at Mount 

Rainier (Russell, 1898). Russell (p. 407) observed that 

Emmons Glacier, as well all others that were visited, 

showed evidence of recent recession by the presence

of nearly bare morairies around the margins of the 

glaciers upon which young trees were beginning to 

grow. The oldest trees between this moraine of Emmons Glacier and the next one downvalley, the 1849 moraine, are now 80 to 90 years old. Of 11 trees cored 

here, 9 range from 70 to 80 years. When Russell 

saw Emmons Glacier in 1896, the oldest trees between 

the end of the glacier and the 1849 moraine were 17 

to 27 years old. Most of them were between 7 and 17 

years. On the 1849 moraine, the oldest trees were 

42 years old and half of them were less than 25 years 

old. Thus the trees upvalley from the 1849 moraine 

were the young trees that Russell (1896) mentioned. 

Because a conspicuous moraine is located near the position of the ice front where Russell saw it, a minor 

readvance of Emmons Glacier probably occurred at 

about this time; the recent recession which Russell 

found probably started about 1849 at Emmons.

The moraine marking the maximum modern advance 

of Emmons Glacier, from which the front started to
A-18 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

recede about 1745 is not present in the Nisqually River 

valley.

MORAINES OF TAHOMA GLACIER

Tahoma Glacier is located at the head of South 

Puyallup Eiver on the west side of Mount Rainier 

(fig. 1). A brief study was made in a small area on 

the left side of South Puyallup River valley near the 

location of the glacier terminus in 1913 and extending 

downvalley across two moraines into an old forest. 

A short arc of an outer moraine is present in only one 

part of the area studied. The remainder of the moraine represented by the outer arc was obliterated by 

a younger advance of the glacier that extended farther 

downvalley.

The inner moraine is younger and the trees sampled 

range in age from 107 to 119 years. The oldest tree 

started to grow in 1840 and thus the glacier probably 

started to recede about 1835. The stand has the appearance of a young forest, and these living trees 

are believed to be the first to grow on the moraine 

since the ice receded from this position.

The arc of the outer moraine curves more sharply 

at both ends toward the axis of the valley than does 

the arc of the younger moraine. The glacial advance 

that formed the 1835 moraine extended across the older 

moraine but probably extended only a short distance 

farther downvalley, as shown in class B2 (fig. 5).

Only six trees on the older moraine were cored; the 

oldest tree is 320 years old, thus it started to grow in 

1639. The trees on this moraine range in diameter 

from 18 to 40 inches, and they, too, appear to be of 

the first generation to grow since the ice receded. 

Many trees have fallen across this moraine but all are 

smaller than the standing trees. The young forest on 

the inner moraine is sufficiently close that the smaller 

trees could have grown on it and have fallen across 

the older moraine. There is no evidence that large 

trees have fallen on the moraine that are as old or 

older than the oldest living ones.

These two moraines, the young one and the one 

from which ice started to recede about 1635, are the 

only moraines found in the area studied on the left 

side of South Puyallup River valley (fig. 15). Evidence of the 1635 moraine was not found near either 

Nisqually or Emmons Glaciers.

The forest downvalley and upslope from both moraines below Tahoma Glacier is old. The largest count 

obtained was 338 years from a core from part of the 

radius of a 40-inch noble fir. Many fallen logs in all 

stages of decay as well as thick humus, composed largely 

of rotten wood, characterizes the old forest. Two trees, 

which are growing on fallen logs, are 182 and 198 years 

old; thus the fallen trees died before 1777 and 1761. 

The log upon which the 182-year old tree is growing

FIGURE 15. The old forest and the 1635 and 1835 moraines downvalley from Tahoma Glacier. Man in extreme left center is standing on old 

surface ; man in extreme right is standing on downvalley limit of the 1835 moraine. The ridge from the lower left to center is the 

1635 moraine. Tree A is 320 years old; tree B is 317 years old. July 22, 1959.
BOTANICAL EVIDENCE OF THE MODERN HISTORY OF NISQUALLY GLACIER A-19

is 13 inches in diameter 10 feet from the roots, and the 

wood in the center is still sound. Therefore, the presence of humus layers composed of completely decayed 

wood signifies that the surface has been forested for a 

long time.

The two moraines represent the maximum advance of 

Tahoma Glacier in a period that may also prove to be 

at least one thousand years. Their configuration shows 

that the ice front during the earlier advance had a shape 

different from that of the later advance even though 

both must have reached about the same distance downvalley. Furthermore, in the areas studied in the 

vicinity of three glaciers flowing from Mount Rainier, 

evidence of a recession in the 17th century was found 

only at Tahoma Glacier. The possibility that such 

evidence exists elsewhere, however, is not precluded 

although it apears doubtful that further work at Nisqually Glacier will uncover it. The examination of the 

area at Emmons Glacier was too incomplete to justify 

an early conclusion about a 17th century advance.

SUMMARY AND CONCLUSIONS

A prominent end moraine below Nisqually Glacier 

marks the greatest downvalley advance of the glacier 

in its modern history. The glacier started to recede 

from its point of maximum advance about 1840. This 

estimate is based on the ages of trees growing on the 

moraine and includes an interval of about 5 years for 

trees to become established after glaciation. Evidence 

in the Nisqually and White River valleys shows that 

trees become established 1 to 14 years after a glacier 

recedes from a given position. Although much information is available on the positions of the terminus of 

Nisqually Glacier during its recession from this maximum point, and a few sections of lateral moraines 

exist on the right valley slope in the vicinity of Tato 

Falls, no prominent moraines other than the 1840 moraine exist that can be dated from botanical evidence 

alone.

The relation of the maximum recent advance of Nisqually Glacier, marked by the 1840 moraine, to the next 

earlier advance is inferred from the age of the forest 

downvalley from the moraine and from examination 

of the layers of organic matter and pumice overlying 

the till representing the last glaciation of the area. The 

present forest with a maximum age of about 300 years, 

plus a humus layer at the surface consisting of rotten 

wood and representing at least 200 years, plus charcoal beneath the humus representing an earlier generation of trees of at least 100 to 200 years of age, represent 

a total of 600 to 700 years. The several organic matter 

and pumice layers underneath the humus and charcoal 

layers certainly represent 300 years or more. Thus the

time that elapsed between the last major glaciation of 

Nisqually Valley and the advance marked by the 1840 

moraine was probably at least a thousand years. Further study of the sequences of pumice layers may increase the estimate of the length of this period by several 

thousand years. However, the maximum advance of 

Nisqually Glacier in at least a thousand years undoubtedly occurred in about 1840.

Incomplete studies of the moraines below Emmons 

and Tahoma Glaciers revealed a prominent moraine 

in each valley corresponding in time to the 1840 terminal moraine of Nisqually Glacier. These studies indicate that Tahoma Glacier started to recede about 1835 

and that Emmons Glacier started to recede about 1850. 

In contrast to Nisqually Glacier, however, prominent 

moraines below Emmons Glacier and botanical evidence 

indicate that maximum positions attained by two other 

advances occurred in 1745 and 1895. The maximum 

modern advance of Emmons Glacier is marked by the 

1745 moraine. At Tahoma Glacier a small segment of 

a 1635 moraine was discovered which indicates that the 

advances marked by the 1635 and the 1835 moraines 

reached about the same extent downvalley. The 1635 

moraine found below Tahoma Glacier was not found 

at Nisqually or Emmons Glaciers but present studies 

do not permit the conclusion that it does not exist at 

these places. The following table summarizes the history of these recessions.

Nisqually 

Glacier

Emmons 

Glacier

Tahoma 

Glacier

Estimated date of start of recession from maximum advance

1845

1895 

1850

1745

1835 

1635

Estimated age, in years, of surface beyond oldest dated moraine

>1000 >700 >1000?

Evidence that ice started to recede from prominent 

moraines below three glaciers during the period 1835- 

50 suggests that the advance of each glacier during this 

period was approximately concurrent. No significance 

is attached to the 15-year spread in the three date determinations. However, the advance that occurred during this period was exceeded at Emmons Glacier by an 

advance that began to recede from the maximum point 

about 1745 and was equaled or exceeded by one at
A-20 BOTANICAL EVIDENCE OF GLACIER ACTIVITY

Tahoma Glacier that began to recede from its maximum 

point about 1635. Thus the evidence indicates that because of the probable similarity of climatic trends 

around Mount Kainier the glaciers on its slopes may 

advance and retreat in approximate synchronization. 

However, the data indicate that the relative degree of 

downvalley advance varies considerably at the different 

locations in accord with glacier behavior as noted by 

other investigators (Sharp, 1951b, p. 106).

Thus, only a start has been made in the accumulation 

of data on glacial history at Mount Kainier from which 

climatic variations can be inferred within the past 

several hundred years. The authors expect to continue 

these studies in order to accumulate additional information 011 several other glaciers of Mount Kainier and 

their environs. In addition to the collection of data on 

specific glacier movements at other locations several 

related problems require further study: (a) Botanical 

evidence that can be used to determine the time of past 

glacier advances as well as the further refinement of 

evidence that is used to determine the time of the start 

of a recession; (b) evidence of flooding and ponding 

along possible marginal drainage channels; (c) data on 

the rate of wood decay in different environments and the 

development of methods of measuring the degree of 

decay so that more positive age determinations can be 

made on the basis of fallen logs; and (d) botanical 

evidence that can be used to distinguish mudflow deposits from glacial moraines.

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o