Pacific Northwest 

Research Station

General Technical 

Report

PNW-GTR-894

June 2014

United States Department of Agriculture 

Forest Service

North Fork Silver Creek

Research Natural Area: 

Guidebook Supplement 47

Reid Schuller, Rachel Showalter, Tom Kaye, and 

Beth Lawrence 
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Authors

Reid Schuller is a plant ecologist, Western Stewardship Science Institute, P.O. Box 

1173, Bend, OR 97709; Rachel Showalter is a botanist, Grants Pass Resource AreaMedford District, Bureau of Land Management, Grants Pass, OR 97526; Tom Kaye

is executive director and plant ecologist, Institute for Applied Ecology, Corvallis, 

OR 97330; Beth Lawrence is a botanist, Institute for Applied Ecology, Corvallis, 

OR 97330. The Pacific Northwest Research Station is publishing this guidebook 

as part of a continuing series of guidebooks on federal research natural areas 

begun in 1972. 

Front cover. North Fork Silver Creek Research Natural Area (RNA). Looking 

north across north-facing slope into North Fork Silver Creek (low-elevation 

ravine). Forest edge (midrange) is RNA boundary. 
Abstract

Schuller, Reid; Showalter, Rachel; Kaye, Tom; Lawrence, Beth. 2014. North 

Fork Silver Creek Research Natural Area: guidebook supplement 47. Gen. Tech. 

Rep. PNW-GTR-894. Portland, OR: U.S. Department of Agriculture, Forest 

Service, Pacific Northwest Research Station. 25 p.

This guidebook describes major biological and physical attributes of the 243-ha 

(600-ac) North Fork Silver Creek Research Natural Area (RNA), Josephine County, 

Oregon. Chosen to represent the diversity of shrub species that occur in the western 

Siskiyou Mountains on non-serpentine metamorphic bedrock, the RNA supports 

manzanita (Arctostaphylos spp.), giant chinquapin (Chrysolepis chrysophylla), deer 

oak (Quercus sadleriana), Sierra laurel (Leucothoe davisiae), Pacific rhododendron 

(Rhododendron macrophyllum), and salal (Gaultheria shallon). The site was also 

designated to represent examples of two forest types present on non-serpentine soils 

in southwestern Oregon: (1) Port Orford cedar-western hemlock (Chamaecyparis 

lawsoniana-Tsuga heterophylla) with Sierra laurel and western swordfern (Polystichum munitum); and (2) white fir/Cascade barberry (Abies concolor/Berberis 

nervosa) forest with longtube twinflower (Linnaea borealis) and sweet after death 

(Achlys triphylla).

Keywords: Research natural area, area of critical environmental concern,

conifer diversity, shrub diversity, manzanita (Arctostaphylos spp.), giant chinquapin (Chrysolepis chrysophylla), Sadler oak (Quercus sadleriana), Sierra laurel 

(Leucothoe davisiae), Pacific rhododendron (Rhododendron macrophyllum), salal 

(Gaultheria shallon), Port Orford cedar (Chamaecyparis lawsoniana), western 

hemlock (Tsuga heterophylla), white fir (Abies concolor), Douglas-fir (Pseudotsuga 

menziesii). 
Preface

The research natural area (RNA) described in this supplement1 is administered by 

the Medford District, Bureau of Land Management (BLM), U.S. Department of the 

Interior. 

North Fork Silver Creek RNA is part of a federal system2 of natural areas established for research and educational purposes.3

 Of the 183 federal RNAs established 

in Oregon and Washington, 45 are described in Federal Research Natural Areas in 

Oregon and Washington: a Guidebook for Scientists and Educators (see footnote 1).

This report is a supplement to the guidebook. 

Each RNA is a site where elements4 are protected or managed for scientific 

purposes and natural processes are allowed to dominate. The objectives for establishing RNAs are to:

• Maintain a wide spectrum of high-quality areas that represent the major 

forms of variability found in forest, shrubland, grassland, alpine, and natural situations that have scientific interest and importance that, in combination, form a national network of ecological areas for research, education, 

and maintenance of biological diversity.

• Preserve and maintain genetic diversity, including threatened, endangered, 

and sensitive species.

• Protect against human-caused environmental disruptions.

• Serve as reference areas for the study of natural ecological processes, 

including disturbance.

1

 Supplement No. 43 to Franklin, J.F.; Hall, F.C.; Dyrness, C.T.; Maser, C. 1972. Federal 

research natural areas in Oregon and Washington: a guidebook for scientists and educators. 

Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest 

and Range Experiment Station. 498 p.

2

 Six federal agencies cooperate in this program in the Pacific Northwest: U.S. Department 

of the Interior, Bureau of Land Management, Fish and Wildlife Service, and National Park 

Service; U.S. Department of Agriculture, Forest Service; U.S. Department of Energy; and 

U.S. Department of Defense. In addition, the federal agencies cooperate with state agencies 

and private organizations in Oregon and Washington in the Pacific Northwest Interagency 

Natural Area Committee. 

3

 See Wilson et al. (2009) for a more complete discussion of rationale for establishment of 

research natural areas.

4

 Elements are the basic units to be represented in a natural area system. An element may 

be an ecosystem, community, habitat, or organism. Taken from Dyrness, C.T.; Franklin, 

J.F.; Maser, C.; Cook, S.A.; Hall, J.D.; Faxon, G. 1975. Research natural area needs in the 

Pacific Northwest: a contribution to land-use planning. Gen. Tech. Rep. PNW-38. Portland, 

OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range 

Experiment Station. 231 p.
• Provide onsite and extension educational activities.

• Serve as baseline areas for measuring long-term ecological changes.

• Serve as control areas for comparing results from manipulative research.

• Monitor effects of resource management techniques and practices. 

The guiding principle in managing RNAs is to maintain natural ecological 

processes or conditions for which the site is designated. Activities that impair scientific or educational values are not permitted within RNAs. Management practices 

necessary to maintain or restore ecosystems may be allowed.5

Federal RNAs provide a unique system of publicly owned and protected examples of relatively unmodified ecosystems where scientists can conduct research 

with minimal interference and reasonable assurance that investments in long-term 

studies will not be lost to logging, land development, or similar activities. Scientists 

and educators wishing to visit or use North Fork Silver Creek RNA for scientific or 

educational purposes should contact the Medford BLM district office manager in 

advance and provide information about research or educational objectives, sampling 

procedures, and other prospective activities. Research projects, educational visits, 

and collection of specimens from the RNA all require prior approval. There may be 

limitations on research or educational activities. 

A scientist or educator wishing to use the RNA is obligated to:

• Obtain permission from the appropriate administering agency before using 

the area (see footnote 2)

• Abide by the administering agency’s regulations governing use, including 

specific limitations on the type of research, sampling methods, and other 

procedures.

• Inform the administering agency on progress of the research, published 

results, and disposition of collected materials.

The purpose of this approval process is to:

• Ensure that the ecological integrity and scientific and educational values of 

the RNA are not compromised.

• Provide information to scientists about other research occurring on the 

RNA so that potential collaborations may be fostered and conflicts avoided. 

5

 Wilson, T.M.; Schuller, R.; Holmes, R.; Pavola, C.; Fimbel, R.A.; McCain, C.N.; Gamon, 

J.G.; Speaks, P.; Seevers, J.I.; DeMeo, T.E.; Gibbons, S. 2009. Interagency strategy for the 

Pacific Northwest Natural Areas Network. Gen. Tech. Rep. PNW-GTR-798. Portland, OR: 

U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 33 p. 
• Maintain records of research activities and research results to benefit the 

BLM, other agencies, and future researchers. 

Appropriate uses of RNAs are determined by the administering agency. 

Destructive analysis of vegetation is generally not allowed, nor are studies requiring extensive substrate modification such as extensive soil excavation. Collection 

of plant and animal specimens is generally restricted to voucher specimens or 

approved research activities. Under no circumstances may collecting significantly 

reduce species populations. Collecting must also be carried out in accordance with 

all other federal and state agency regulations. 
Contents

1 Introduction

1 Access and Accommodations

2 Environment

3 Climate

5 Vegetation

12 Fauna

13 Disturbance History

14 Research History

14 Maps

14 Acknowledgments

15 English Equivalents

15 References 

18 Appendix 1: Plants

22 Appendix 2: Amphibians, Reptiles, Birds, and Mammals
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

Introduction

North Fork Silver Creek Research Natural Area (RNA) is located approximately 

40 km (25 mi) west-northwest of Grants Pass in Josephine County, Oregon. The 

243-ha (600-ac) site was established as an Area of Critical Environmental Concern/

RNA in 1995. This management designation was subsequently reaffirmed in the

Medford District Resource Management Plan (Federal Register 1995, USDI BLM 

1995).

The RNA has been established because it supports examples of two forest 

communities on non-serpentine soils (e.g., gabbro) within the Siskiyou Mountains (Klamath Mountains ecoregion): (1) Port Orford cedar-western hemlock 

(Chamaecyparis lawsoniana-Tsuga heterophylla) with Sierra laurel (Leuocothoe 

davisii), and western swordfern (Polystichum munitum); and (2) white fir/Cascade 

barberry (Abies concolor/Berberis nervosa) moderately dry site forest with longtube twinflower (Linnaea borealis var. longiflora) and sweet after death (Achlys 

triphylla) (ONHAC 2010). Additionally, conifer and shrub diversity are high, and 

include paleo-endemics such as Brewer spruce (Picea breweriana) and deer oak 

(Quercus sadleriana). The site also appears to be a stronghold for Sierra laurel, a 

special-status species (USDI BLM 2004). 

Access and Accommodations

The RNA is located in sections 15 and 16, Township 35 South, R 9 West, Willamette Meridian, in Josephine County, Oregon. To access the area from Interstate 

5 north of Grants Pass, Oregon, take the Merlin exit # 61 and head west on Merlin 

Road through the town of Merlin, Oregon. From this point, the road turns into 

Galice Road. At 23.8 km (14.8 mi) from Interstate 5, turn left onto road # 34-8-36.0. 

This turn is also marked at the road to Gold Beach, and it occurs just after passing 

over a bridge. Continue on paved road 34-8-36.0. At 38.5 km (23.9 mi), stay on road 

marked to Gold Beach. At 39.4 km (24.5 mi), go left downhill on 35-9-1.0 (paved). 

To access the upper slopes of North Fork Silver Creek RNA, turn left at 42.8 km 

(26.6 mi) and cross over creek and proceed uphill. To access lower elevations within 

the RNA, continue east along the North Fork of Silver Creek for an additional 1.3 

km (0.8 mi) (fig. 1). 

Prior to visiting the site, obtain permission to access the area for research or 

educational purposes at the Bureau of Land Management (BLM), Medford District 

office in Medford, Oregon. Maps and additional directions to the area are available 

at this office. Lodging is available in Grants Pass, Oregon. 
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Environment 

The RNA is situated within the Silver Creek drainage basin in the central Siskiyou 

Mountains of southwestern Oregon (USDI BLM 2011, ONHAC 2010). Elevations within the RNA range from about 730 m (2,395 ft) adjacent to North Fork 

Silver Creek on the north boundary to 1200 m (3,937 ft) on the upper slopes of the 

south boundary. The generally north-facing slopes are incised by three intermittent streams, which originate within the RNA providing 1st- and 2nd-order stream 

reaches, which flow into the North Fork Silver Creek, a 3rd-order stream. The micro 

Figure 1—North Fork Silver Creek Research Natural Area location and access. 
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

topography formed by side slopes of the streams provides east- and west-facing 

side canyons (fig. 2). The steep, rugged terrain is typical of many areas within the 

Siskiyou Mountains (USDI BLM 2004). 

Bedrock geology in the area occurs as a broad north-south band, which is 

composed primarily of intrusive metamorphosed volcanic, rocks. This band was 

consolidated through plate tectonic activity from the early to late Jurassic period 

(approximately 150 to 190 million years ago) (OR DOGAMI 1979).

The Beekman and Vermisa soil series predominate throughout the RNA. 

Beekman series soils are moderately deep, well-drained soils that formed in colluvium weathered from altered sedimentary and extensive igneous rocks. The 

Vermisa series consists of shallow, somewhat excessively drained soils that formed 

in colluvium and residuum weathered from metasedimentary or metavolcanic 

rocks. Vermisa soils are on mountain side slopes and canyon walls. The two series 

often occur together as a complex within the North Fork Silver Creek RNA (USDA 

NRCS 2013b). 

Climate

The North Fork Silver Creek watershed has a marine-influenced Mediterranean climate with cool, wet winters and warm, dry summers. From late fall through spring, 

unstable low-pressure air masses from the Pacific Ocean bring frequent storms, 

sometimes accompanied by high winds. During the summer, stable high-pressure 

air masses bring generally clear skies and temperature inversions. Temperatures are 

modified by proximity to the Pacific Ocean—in winter by its warming influence, 

and in summer by its cooling influence (USDI BLM 2004). 

The precipitation is in the form of rain and snow. About 95 percent of the Silver 

Creek watershed is in the transient snow zone where snowpacks accumulate and 

melt throughout the winter in response to alternating cold and warm fronts. Average annual precipitation in the watershed is highly variable, ranging between about 

1371 and 3048 mm (54 and 120 in) with the average amounts increasing from east 

to west (USDI BLM 2004). 

The nearest weather station with climate data roughly comparable to the RNA 

is in Illahe, Oregon (354133), located about 67 km (40 mi) northwest of the RNA 

(table 1). Here, extended periods of cloudiness and heavy periods of precipitation 

occur during the winter. About 80 percent of average annual precipitation falls from 

November through March. Annual precipitation occurs as a mixture of rain and 

snow, averaging 208 cm (82 in) per year. Six percent of the average annual precipitation falls from May through August (WRCC 2013). Precipitation is likely 10 
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Figure 2—North Fork Silver Creek Research Natural Area topography, elevation, hydrology, and 

boundary. 
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

to 20 percent higher within the RNA than the Illahe weather station data indicate. 

Snowfall occurs predominantly from December through March. Table 1 provides an 

approximation of precipitation and temperature regimes affecting the RNA. 

Vegetation

Represented on the site is a diversity of shrub species that occur in the western 

Siskiyou Mountains on non-serpentine, igneous and meta-igneous bedrock (gabbro).

The RNA supports manzanita (Arctostaphylos spp.), giant chinquapin (Chrysolepis 

chrysophylla), deer oak, Pacific rhododendron (Rhododendron macrophyllum), and 

salal (Gaultheria shallon). Red alder (Alnus rubra) dominates the lower riparian 

zone but is replaced by coniferous forest on the upper reaches. This forest contains 

Port Orford cedar (Cupressus lawsoniana) and Douglas-fir (Pseudotsuga menziesii) 

in the moist draw with salal, deer oak, and Pacific rhododendron in the understory. 

Upslope forests comprise white fir and western hemlock with sporadic red huckleberry (Vaccinium parviflora) and tanoak (Notholithocarpus densiflorus). Upper 

slopes are more xeric, and support 150-year-old Douglas-fir, sugar pine (Pinus 

lambertiana), and ponderosa pine (Pinus ponderosa), with white fir regeneration in 

the understory. Knobcone pine (Pinus attenuata is scattered at upper elevations and 

occupies previously burned sites. 

Existing vegetation within the North Fork Silver Creek RNA can be identified 

as community types using current vegetation. Community type names follow those 

identified in Field Guide to the Plant Associations of Southwestern Oregon (Atzet 

et al. 1996) or are compared to types described by them. Atzet et al. (1996) classify 

plant associations using current vegetation to identify potential natural vegetation 

that would be present under climax conditions. Stands within the RNA are not in 

climax condition, owing in large part to recent natural disturbances such as wildfire 

Table 1—Temperature and precipitation summary, (354133) 

10/1/1938 to 6/30/2007—Illahe, Oregon

Average minimum January temperature 2.2 °C (36.0 °F)

Average maximum January temperature 9.4 °C (48.9 °F)

Average minimum July temperature 11.7 °C (52.1 °F)

Average maximum July temperature 31.1°C (88.0 °F)

Average annual precipitation 2080 mm (81.90 in)

Average June–August precipitation 58 mm (2.28 in)

Average annual snowfall 272 mm (10.70 in)
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Figure 3—Plant communities of North Fork Silver Creek Research Natural Area (RNA). 
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

(see “Disturbance History” section). Plant community type descriptions (Lawrence 

and Kaye 2003) and distribution within the RNA (fig. 3) follow. 

The tanoak-white fir/Cascade barberry community predominates on northeast 

aspects at lower elevation within the RNA. The overstory is dominated by Douglasfir (Pseudotsuga menziesii) with about 50 percent canopy cover, and with lesser 

amounts of white fir, Brewer spruce, and western yew (Taxus brevifolia). Giant 

chinquapin and canyon live oak are present in the subcanopy. The shrub layer is 

dominated by tanoak and Cascade barberry. Other shrubs present include salal, deer 

oak, Pacific rhododendron, dwarf rose (Rosa gymnocarpa), thimbleberry (Rubus 

parviflorus), common whipplea (Whipplea modesta), and Oregon boxleaf (Paxistima myrsinites). The herbaceous layer is comprised of sweet after death, dogbane 

(Apocynum androsaemifolium), pipsissewa (Chimaphila umbellata), drops-of-gold 

(Prosartes hookeri), yellowleaf iris (Iris chrysophylla), longtube twinflower, 

whiteveined wintergreen (Pyrola picta), broadleaf starflower (Trientalis borealis

ssp. latifolia), Pacific trillium (Trillium ovatum), and western rattlesnake plantain 

(Goodyera oblongifolia). Species richness within this community is 31 in the RNA. 

This community type is very similar to that described by Atzet et al. (1996) as 

tanoak/white fir/Cascade barberry, but differs in lacking incense cedar (Calocedrus 

decurrens) in the overstory (Lawrence and Kaye 2003). 

Douglas-fir/giant chinquapin/Cascade barberry is a steep northwest-facing 

community with a slope of 60 to 88 percent and occupies the northern portion of 

the RNA. Douglas-fir dominates the canopy with about 80 percent cover, while 

sugar pine contributes about 10 percent cover to the overstory. Other conifers scattered throughout the community include grand fir (Abies grandis), western white 

pine (Pinus monticola), and western hemlock. Giant chinquapin is the dominant 

subcanopy hardwood, and Pacific madrone is scattered throughout. The shrub layer 

is diverse and is represented by Cascade barberry, salal, tanoak, deer oak, Pacific 

madrone, dwarf rose, California dewberry (Rubus ursinus), common snowberry 

(Symphoricarpos albus), red huckleberry (Vaccinium parviflorum), bearbrush (Garrya fremontii), California coffeeberry (Rhamnus californica ssp. occidentalis), and 

common whipplea. The total species richness for this community in the North Fork 

Silver Creek RNA is 43, which differs from Atzet et al.’s (1996) average species 

richness for the community type of 28, primarily owing to a more diverse tree and 

shrub community (Lawrence and Kaye 2003). 

A sugar pine/deer oak community type occupies several different aspects, 

including northwest- and northeast-facing slopes. A forked drainage with a diverse 

array of plant life runs through this community but is classified as a riparian association. The sugar pine/deer oak community type is rich in diversity with 57 different 
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Figure 4—High-elevation ridgeline community with knobcone pine, sugar pine, Douglas-fir, white 

fir, and western hemlock present. Shrubs include Pacific rhododendron, manzanita subspecies 

Cascade barberry, western teaberry, tanoak, deer oak, and red huckleberry.

vascular plants present. It is topographically situated on the upper half of the RNA, 

ranging in elevation from 951 to 1170 m (3,120 to 3,840 ft), and occupies several 

different aspects. Sugar pine is an overstory dominant in this community, while 

deer oak contributes the greatest amount of cover (20 percent) to the shrub layer 

(fig. 4). Although sugar pine is the most prevalent tree, other tree species contribute 

to the diverse canopy, including white fir, grand fir, noble fir (Abies procera), Port 

Orford cedar, knobcone pine (Pinus attenuata), ponderosa pine, Douglas-fir, and 

western hemlock. Canyon live oak is the primary understory hardwood. Common 

shrubs within the community include Pacific madrone, Waldo manzanita (Arctostaphylos cinerea), Eastwood’s manzanita (A. glandulosa), and pinemat manzanita 

(A. nevadensis); Cascade barberry; western teaberry (Gaultheria ovatifolia), 

bearbrush; tanoak; deer oak; California coffeeberry; Pacific rhododendron; and 

red huckleberry. Typical herbaceous species include sugar stick (Allotropa virgata) 

(fig. 5), dogbane, Klamath arnica (Arnica spathulifolia), pipsissewa, drops-of-gold, 

elegant piperia (Piperia elegans), yellowleaf iris, longtube twinflower, whiteveined 

wintergreen, sanicle (Sanicula sp.), snowplant (Sarcodes sanguinea), and common 

beargrass (Lawrence and Kaye 2003). Long-term vegetation monitoring plots were 

established in this community in 2012 (Schuller et al. 2012). 
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Figure 5—Understory conditions within the tanoak-Douglas-fir-canyon live oak/Cascade barberry 

plant community. Douglas-fir is the overstory dominant and Pacific rhododendron, deer oak, and red 

huckleberry occur as major shrubs. Herbaceous diversity is low in this stand. 

A tanoak-Douglas-fir-canyon live oak/Cascade barberry plant association 

occurs within the central portion of the RNA between 829 and 1183 m (2720 and 

3880 ft) elevation (fig. 6). It is on both the western and eastern sides by the central 

drainages that run through the RNA. The aspect for this community is variable 

and ranges from north to west to northeast, while the slope steepness varies from 

30 to 60 percent. Plant species richness is moderately high (n = 48). Douglas-fir, 

sugar pine, and western white pine dominate the overstory. Pacific madrone, 

incense cedar, giant chinquapin, knobcone pine, and western hemlock are minor 

to subdominant components to the mid - and upper -canopy. However, on westfacing slopes sugar pine is clearly dominant, whereas on the northeast-facing slopes 

western white pine is more abundant. The shrub component is very similar to 

that of the sugar pine/deer oak community (see above), except that tanoak, Pacific 

rhododendron, and canyon live oak are dominant here. The species rich herbaceous 

layer is represented by sweet after death, dogbane, variableleaf collomia (Collomia 

heterophylla), white hawkweed (Hieracium albiflorum), yellowleaf iris, longtube 

twinflower, whiteveined wintergreen, broadleaf starflower, Pacific trillium, common beargrass, frosted Indian paintbrush (Castilleja pruinosa), Washington lily 
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general technical report pnw-gtr-894

(Lilium washingtonianum), shrubby bedstraw (Galium multiflorum), old-man-inthe-Spring (Senecio vulgaris), and big deervetch (Lotus crassifolius). The composition of this community type differs from that described by Atzet et al. (1996) in 

that western white pine is an important component of the overstory, and poison oak 

(Toxicodendron diversilobum) is absent from it on the RNA (Lawrence and Kaye 

2003). Long-term vegetation monitoring plots were established in this community 

in 2012 (Schuller et al. 2012). 

The Douglas-fir/Pacific rhododendron-salal is a steep, northwest-facing plant 

community occupying the eastern boundary of the RNA and extends from 829 m 

(2,720 ft) elevation adjacent to the North Fork Silver Creek up to the highest point 

in the RNA at 1195 m (3,920 ft) elevation. Slope steepness varies from 30 to 65 

percent. This community is characterized by Douglas-fir being a major canopy 

dominant and Port Orford cedar being a minor associated species. Grand fir, sugar 

pine, and western hemlock add to the conifer diversity in this community. Giant 

chinquapin comprises about 20 percent of the midcanopy layer, but much of it is 

resprouting after being burned in the 2002 Biscuit Fire. 

The shrub layer is dominated by Pacific rhododendron and salal. Other species 

occupying the shrub layer include Cascade barberry, tanoak, canyon live oak, deer 

Figure 6—Red alder stand adjacent to northern Research Natural Area boundary along North Fork 

Silver Creek, with well-developed shrub layer including currant subspecies, common snowberry, 

vine maple, Saskatoon serviceberry, redosier dogwood, and willow subspecies.
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

oak, huckleberry oak (Quercus vaccinifolia), dwarf rose, red huckleberry, and common whipplea. The herbaceous layer consists of sweet after death, dogbane, Klamath arnica drops-of-gold, shrubby bedstraw, yellowleaf iris, longtube twinflower, 

whiteveined wintergreen, Pacific trillium, common beargrass, and western brackenfern. This community exhibits a species richness of 29 compared to an average of 

20 in Atzet et al.’s (1996) description of the Douglas-fir/salal/Pacific rhododendron 

plant association. Their characterization of this community also did not include Port 

Orford cedar, grand fir, or western hemlock (Lawrence and Kaye 2003).

The North Fork Silver Creek RNA also contains riparian areas of first- and 

second-order intermittent streams. Two central drainages run through the heart of 

the RNA. These first- and second-order streams drain off the ridge that divides the 

north fork from the main fork of Silver Creek. Although relatively small, these areas 

support substantial floristic diversity. They typically occur on north-facing slopes 

and vary in steepness from 20 to 60 percent. These community types are diverse 

with a species richness of 52 and are inhabited by many species tolerant of mesic 

microsites. 

Incense cedar and western hemlock are the principal overstory conifers. Port 

Orford cedar, Douglas-fir, western yew, and red alder (Alnus rubra) are also frequent overstory associates. Salal and Pacific rhododendron are shrub layer dominants. Other common shrubs include Cascade barberry, western teaberry, Sierra 

laurel, western azalea (Rhododendron occidentale), dwarf rose, California dewberry, and red huckleberry. The herbaceous layer includes sugar stick (Allotropa 

virgata), sweet after death, coastal brookfoam (Boykinia elata), bunchberry 

dogwood (Cornus canadensis), California pitcherplant (Darlingtonia californica), 

western rattlesnake plantain, Leopard lily (Lilium pardalinum, Washington lily 

(L. washingtonianum), longtube twinflower, muskflower (Mimulus moschatus), 

Brewer’s miterwort (Mitella breweri), oneleaf foamflower (Tiarella trifoliata var. 

unifoliata), broadleaf starflower, Pacific trillium, brook wakerobin (T. rivale), and 

green false hellebore (Veratrum viride) (Lawrence and Kaye 2003).

The North Fork Silver Creek is a third-order stream that flows from east to west 

adjacent to the northern boundary of the RNA. It occupies the lowest topographic 

position in the RNA, with an average elevation of 819 m (2,680 ft). This is the most 

species-rich community in the RNA, with a total of 77 vascular plant species. 

Incense cedar and Douglas-fir are the dominant canopy trees, with sugar 

pine being a minor associate. Other tree species include white fire, red alder, Port 

Orford cedar, willow (Salix sp.), and western yew. Common shrubs contributing to 

the understory diversity include giant chinquapin, vine maple (Acer circinatum), 

Saskatoon serviceberry (Amelanchier alnifolia), hollyleaved barberry (Berberis 
12

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aquifolium), snowbrush ceanothus (Ceanothus velutinus), Pacific dogwood (Cornus 

nuttallii), redosier dogwood (C. sericea ssp. stolonifera), salal, Sierra laurel, Pacific 

rhododendron, western azalea (Rhododendron occidentale), stink currant (Ribes 

bracteosum), redflower currant (R. sanguineum), common snowberry, and red 

huckleberry. 

The herbaceous layer consists of Pacific onion (Allium validum), western 

columbine (Aquilegia formosa), British Columbian wildginger (Asarum caudatum), 

coastal brookfoam, American skunkcabbage (Lysichiton americanus), scarlet monkeyflower (Mimulus cardinalis), muskflower, coastal miterwort (Mitella ovalis), 

Oregon fetid adderstongue (Scoliopus hallii), arrowleaf ragwort (Senecio triangularis), bigflower tellima (Tellima grandiflora), threeleaf foamflower (Tiarella trifoliata), pioneer violet (Viola glabella), ladyfern (Athyrium filix-femina), Henderson’s 

sedge (Carex hendersonii), and fowl mannagrass (Glyceria elata). 

Road 35-9-1 bounds the northern boundary of the RNA. Several vascular plant 

species characteristic of ruderale or disturbed sites occur along this roadside and 

nowhere else within the RNA. This floral assemblage includes three highly invasive, nonnative plant species: Canada thistle (Cirsium arvense), common St. Johnswort (Hypericum perforatum), and oxeye daisy (Leucanthemum vulgare). Native 

species tolerant of disturbance also occupy the roadside habitat: pearly everlasting 

(Anaphalis margaritacea), naked buckwheat (Eriogonum nudum), and Santa Inez 

goldenbanner (Thermopsis macrophylla). 

A list of scientific and common names for vascular plants, lichens, and fungi 

known to occur within the RNA appears in appendixes 1, 2, and 3, respectively. 

Fauna

The diversity of soil types and vegetative communities in the North Fork Silver 

Creek watershed provides potential habitat for a wide range of sensitive animal 

species. Few formal wildlife surveys have been conducted in the watershed to date, 

however. More than 200 vertebrate and thousands of invertebrate wildlife species 

might occur in the watershed. The watershed contains potential habitat for 47 vertebrate special-status species, 15 mammals, 19 birds, and 13 reptiles and amphibians, 

as well as eight invertebrate special-status species (USDI BLM 2004). 

Other vertebrates of concern include cavity nesting species, band-tailed 

pigeons, Neotropical migrant birds, and six birds on U.S. Fish and Wildlife species 

of concern list (most are also BLM special-status species). Of the 47 special-status 

species, most are associated with older forest habitats. However, other important 

habitats to these species include riparian areas and pine stands (USDI BLM 2004), 

such as those occurring within North Fork Silver Creek RNA. 
13

North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

Amphibians, reptiles, birds, and mammals known or expected to occur within 

the RNA are listed in appendix 4. These lists have been derived from published 

literature (Csuti et al. 1997) on the species distribution, life history characteristics, 

and availability of habitat within the RNA. 

Disturbance History

Throughout southwestern Oregon, fire exclusion has resulted in significant 

increases in stand density (stems per acre), shifts in species composition (e.g., 

increases in fire-intolerant, shade-tolerant species), and changes in stand structure. 

These transformations have increased the forest’s susceptibility to large, severe 

fires and epidemic attack by insects and disease and have affected the habitat 

quality for rare plants. Fire exclusion in Silver Creek watershed over the last 100 

years contributed to the size and severity of the Biscuit Fire in 2002. The Biscuit 

Fire burned throughout the Silver Creek and North Fork Silver Creek watersheds 

ultimately burning 500,000+ acres in southwestern Oregon over a 4-month period. 

The large size of this fire is an example of landscape effects where fire has been 

excluded for a long time (USDI BLM 2004). 

Fire is a primary agent of natural disturbance in the North Fork Silver Creek 

watershed. Most of the watershed has historically experienced a mixed- to highseverity fire regime. Mixed-severity fire regimes are associated with infrequent 

fires (35 to 100+ years) of both high and low intensity, creating a mosaic effect. At 

the landscape level, mixed-severity fire regimes create a patchy appearance and 

individual stands will often consist of two or more age classes. A high percentage 

of the Silver Creek watershed’s natural stands have a history of frequent surface 

fires, resulting in two- or three-storied stands where each story is even aged. The 

increase of layered understory vegetation further contributes to fire intensity. 

Waxy-leaved shrubs and trees (such as those occurring within the RNA) can also 

carry flames into the overstory, creating a high-intensity fire. 

The Biscuit Fire of 2002 had a dramatic impact on the plant communities 

within North Fork Silver Creek RNA. The fire affected about 95 percent of the 

RNA, but less than 5 percent was categorized as a high-intensity fire (USDI BLM 

2004). Most of the overstory trees were not killed, whereas the shrub and herb layer 

suffered dramatic dieback. However, the shrub layer exhibited vigorous resprouting, 

allowing for proper species identification (Lawrence and Kaye 2003). 

In addition to fire exclusion, the nonnative Port Orford cedar root disease 

(Phytophthora lateralis) occurs within the watershed. Humans have been the main 

vectors of this pathogen into the watershed. 
14

general technical report pnw-gtr-894

Research History

The following research and monitoring projects have been undertaken within North 

Fork Silver Creek RNA: 

Hawk (1977) studied Port Orford cedar forest types within the RNA 

(Greene et al. 1986). 

Lawrence and Kaye (2006) conducted a floristic inventory and mapped vegetation 

communities present within the RNA. 

Schuller et al. (2012) established long-term vegetation monitoring plots in unburned 

stands within the sugar pine/deer oak plant community, and within the Douglas-fir/

giant chinquapin/Cascade barberry plant community. 

Maps 

Maps applicable to North Fork Silver Creek RNA: Topographic—Hobson Horn, 

Oregon, 7.5 minute, 1:24,000 scale, 1989; Medford District—Western portion, BLM 

transporation map, 1.27 cm = 1.6 km (0.5 in = 1 mi) [2004]. 

Acknowledgments 

The following people merit recognition for their contributions: Steve Haney, 

geographic information specialist, Medford District, BLM, created the maps in 

figures 1, 2, and 3; and Jason Reilly, wildlife biologist, Grants Pass Resource Area, 

Medford District, BLM, reviewed and improved the list of animals in appendix 2. 

We also thank the three manuscript reviewers: Todd Wilson, wildlife biologist and 

research natural area coordinator, U.S. Forest Service, Pacific Northwest Research 

Station; Bryan Wender, BLM Medford district botanist; and Colleen Dulin, BLM 

Grants Pass resource area lead hydrologist. The project is funded through the BLM 

Medford District, and is administratively supported by the USDA Forest Service 

Pacific Northwest Research Station. 
15

North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

English Equivalents

1 hectare (ha) = 2.47 acres (ac)

1 kilometer (km) = 0.62 mile (mi)

1 meter (m) = 3.28 feet (ft)

1 square meter (m2

) = 10.76 square feet

1 centimeter (cm) = 0.394 inch (in)

1 millimeter (mm) = 0.0394 inch

Degrees Fahrenheit (°F) = 1.8 degrees Celsius + 32 

References

Atzet, T.; White, D.E.; McCrimmon, L.A.; Martinez, P.A.; Fong, P.R.; 

Randall, V.D. 1996. Field guide to the forested plant associations of 

southwestern Oregon. Tech. Pap. R6-NR-ECOL-TP-17-96. Portland, OR: 

U.S. Department of Agriculture, Forest Service, Pacific Northwest Region.

http://www.fs.usda.gov/detail/rogue-siskiyou/mapspubs/?cid=stelprdb5319390#top. (April 7, 2013). 

Cook, T.; Sundberg, S., eds. 2013. Oregon vascular plant checklist. Version 1.2. 

http://www.oregonflora.org/checklist.php. (March 21, 2013). 

Csuti, B.; Kimerling, A.J.; O’Neil, T.A.; Shaughnessy, M.M.; Gaines, E.P.; 

Huso, M.M.P. 1997. Atlas of Oregon wildlife. Corvallis, OR: Oregon State 

University Press. 427 p. + map. 

Dyrness, C.T.; Franklin, J.F.; Maser, C.; Cook, S.A.; Hall, J.D.; Faxon, G. 

1975. Research natural area needs in the Pacific Northwest: a contribution to 

land-use planning. Gen. Tech. Rep. PNW-38. Portland, OR: U.S. Department 

of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment 

Station. 231 p. 

Federal Register. 1995. Notices. Medford District Resource Management Plan 

and Record of Decision 60(141): 37900-37902. http://www.gpo.gov/fdsys/pkg/FR1995-07-24/html/95-18063.htm. [Via Government Printing Office].

(July 24, 2013). 

Flora of North America [FNA]. 1993+. Partial nomenclature of vascular plants, 

ferns, and fern allies within Oregon. http://www.efloras.org/flora_page.

aspx?flora_id=1. (January 11, 2011). 
16

general technical report pnw-gtr-894

Franklin, J.F.; Hall, F.C.; Dyrness, C.T.; Maser, C. 1972. Federal research 

natural areas in Oregon and Washington: a guidebook for scientists and 

educators. Portland, OR: U.S. Department of Agriculture, Forest Service, 

Pacific Northwest Forest and Range Experiment Station. 498 p. 

Greene, S.E.; Blinn, T.; Franklin, J.F. 1986. Research natural areas in Oregon 

and Washington: past and current research and related literature. Gen. Tech. Rep. 

PNW-GTR-197. Portland, OR: U.S. Department of Agriculture, Forest Service, 

Pacific Northwest Research Station. 115 p. 

Hawk, G.M. 1977. Comparative studies of temperate Chamaecyparis forests. 

Corvallis, OR: Oregon State University. 79 p. Ph.D. dissertation. 

Lawrence, B.A.; Kaye, T.N. 2003. Vegetation survey of North Fork Silver Creek 

RNA, Medford district, Bureau of Land Management. Unpublished manuscript. 

On file with: Bureau of Land Management, Medford District, 3040 Biddle Road, 

Medford, OR 97504. 

Oregon Department of Geology and Mineral Industries [OR DOGAMI]. 1979.

Geology and mineral resources of Josephine County, Oregon. Bulletin 100. On 

file with: Bureau of Land Management, Medford District, 3040 Biddle Road, 

Medford, OR 97504. 

Oregon Natural Heritage Advisory Council [ONHAC]. 2010. Oregon natural 

areas plan. Oregon Biodiversity Information Center, Institute for Natural 

Resources—Portland. Portland, OR: Portland State University. 198 p. 

Schuller, R.; Greene, S.; Showalter, R. 2012. Unpublished vegetation monitoring 

data. On file with: Bureau of Land Management, Medford District, 3040 Biddle 

Road, Medford, OR 97504. 

U.S. Department of Agriculture, Natural Resources Conservation Service 

[USDA NRCS]. 2013a. Plants database. http://plants.usda.gov/.

(January 19, 2013). 

U.S. Department of Agriculture, Natural Resources Conservation Service 

[USDA NRCS]. 2013b. Soil maps from Josephine County, Oregon. http://

websoilsurvey.nrcs.usda.gov/app/. (April 17, 2013). 

U.S. Department of the Interior, Bureau of Land Management [USDI BLM]. 

1995. Medford District record of decision and resource management plan. On file 

with: Bureau of Land Management, Medford District Office, 3040 Biddle Road, 

Medford, OR 97504. 248 p. + tables and maps. 
17

North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

U.S. Department of the Interior, Bureau of Land Management [USDI BLM]. 

2004. North Fork Silver Creek watershed analysis. On file with: Bureau of Land 

Management, Medford District Office, 3040 Biddle Road, Medford, OR 97504. 

119 p. http://www.blm.gov/or/districts/medford/plans/files/north_fork_silver_

creek_wa_acc.pdf. (April 30, 2013). 

U.S. Department of the Interior, Bureau of Land Management [USDI BLM]. 

2011. Silver Creek watershed—water quality restoration plan HUC 1710031109. 

On file with: Bureau of Land Management, Medford District Office, 3040 Biddle 

Road, Medford, OR 97504. http://www.blm.gov/or/districts/medford/plans/files/

SilverCreekwqrp.pdf. (April 19, 2013). 

Western Regional Climate Center [WRCC]. 2013. Monthly climate summary for 

Illahe, Oregon (354133) 10/1/1938 to 6/30/2007. http://www.wrcc.dri.edu/cgi-bin/

cliMAIN.pl?or4133. (April 25, 2013). 

Wilson, T.M.; Schuller, R.; Holmes, R.; Pavola, C.; Fimbel, R.A.; McCain, 

C.N.; Gamon, J.G.; Speaks, P.; Seevers, J.I.; DeMeo, T.E.; Gibbons, S. 

2009. Interagency strategy for the Pacific Northwest Natural Areas Network. 

Gen. Tech. Rep. PNW-GTR-798. Portland, OR: U.S. Department of Agriculture, 

Forest Service, Pacific Northwest Research Station. 33 p. 
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general technical report pnw-gtr-894

Appendix 1: Plants 1 2

Coniferous trees:

Abies concolor (Gord. & Glend.) Lindl. ex Hildebr. White fir

Abies grandis (Douglas ex D. Don) Lindl. Grand fir

Abies procera Rehd. Noble fir

Calocedrus decurrens (Torr.) Florin Incense cedar

Chamaecyparis lawsoniana A. Murray bis Parl. Port Orford cedar

Picea breweriana S. Wats. Brewer spruce

Pinus attenuata Lemmon Knobcone pine

Pinus lambertiana Dougl. Sugar pine

Pinus monticola Dougl. ex D. Don Western white pine

Pinus ponderosa Laws. Ponderosa pine

Pseudotsuga menziesii (Mirb.) Franco Douglas-fir

Taxus brevifolia Nutt. Western yew

Tsuga heterophylla (Raf.) Sarg. Western hemlock

Deciduous trees > 8 m (26.3 ft) tall

Acer glabrum Torr. var. douglasii (Hook.) Dippel Douglas maple

Alnus rubra Bong. Red alder

Arbutus menziesii Pursh Pacific madrone

Chrysolepis chrysophylla (Dougl. ex Hook.) Hjelmq. Giant chinquapin

Cornus nuttallii Audubon ex Torr. & A. Gray Pacific dogwood

Notholithocarpus densiflorus (Hook. & Arn.) Manos et al. Tanoak

Quercus chrysolepis Liebem. Canyon live oak

Salix sp. Willow

Tall shrubs 2 m to 8 m (6.6 to 26.3 ft) tall:

Acer circinatum Pursh Vine maple

Amelanchier alnifolia (Nutt.) Nutt. ex M. Roem. Saskatoon serviceberry

Cornus sericea ssp. stolonifera Redosier dogwood

Garrya fremontii Torr. Bearbrush

Quercus sadleriana R. Br. Deer oak

Rhododendron macrophyllum D. Don ex G. Don Pacific rhododendron

Medium shrubs 0.5 m to 2m (1.6 to 6.6 ft) tall:

Arctostaphylos ×cinerea Howell (pro sp.) 

[canescens × viscida] Waldo manzanita

Arctostaphylos glandulosa Eastw. Eastwood’s manzanita

Arctostaphylos nevadensis A. Gray Pinemat manzanita

Berberis aquifolium Pursh Hollyleaved barberry

Ceanothus velutinus Dougl. ex Hook. Snowbrush ceanothus

Gaultheria shallon Pursh Salal

Leucothoe davisiae Torr. ex A. Gray Sierra laurel

Paxistima myrsinites (Pursh) Raf. Oregon boxleaf

Quercus vaccinifolia Kellogg Huckleberry oak
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

Rhamnus californica ssp. occidentalis California buckthorn

Rhododendron occidentale (Torr. & Gray) A. Gray Western azalea

Ribes bracteosum Dougl. ex Hook. Stink currant

Ribes sanguineum Pursh Redflower currant

Rosa gymnocarpa Nutt. Dwarf rose

Rubus laciniatus Willd. Cutleaf blackberry

Rubus leucodermis Dougl. ex Torr. & A. Gray Whitebark raspberry

Rubus parviflorus Nutt. Thimbleberry

Symphoricarpos albus (L.) S.F. Blake Common snowberry

Toxicodendron diversilobum (Torr. & A. Gray) Greene Poison oak

Vaccinium parvifolium Sm. Red huckleberry

Low shrubs <0.5 m (1.6 ft) tall:

Berberis nervosa Pursh Cascade barberry

Gaultheria ovatifolia A. Gray Western teaberry

Rubus nivalis Dougl. ex Hook. Snow raspberry

Rubus ursinus Cham. & Schldtl. California dewberry

Whipplea modesta Torr. Common whipplea

Herbs: 

Achlys triphylla (Sm.) DC. Sweet after death

Adenocaulon bicolor Hook. American trailplant

Allium validum S. Wats. Pacific onion

Allotropa virgata Torr. & A. Gray ex A. Gray Sugar stick

Anaphalis margaritacea (L.) Benth. & Hook. Pearly everlasting

Anemone sp. Windflower

Apocynum androsaemifolium L. Dogbane

Aquilegia formosa Fisch. ex DC. Western columbine

Arnica spathulata Greene Klamath arnica

Asarum caudatum Lindl. British Columbian wildginger

Boykinia occidentalis Torr. & A. Gray Coastal brookfoam

Castilleja pruinosa Fernald Frosted Indian paintbrush

Chimaphila menziesii (R. Br. ex D. Don) Spreng. Little prince’s pine

Chimaphila umbellata (L.) Bart. Pipsissewa

Cirsium arvense (L.) Scop. Canada thistle

Claytonia parviflora Dougl. ex Hook. ssp. parviflora Streambank springbeauty

Claytonia sibirica L. Siberian springbeauty

Collomia heterophylla Dougl. ex Hook. Variableleaf collomia

Corallorhiza maculata (Raf.) Raf. Summer coralroot

Cornus canadensis L. Bunchberry dogwood

Darlingtonia californica Torr. California pitcherplant

Dicentra formosa (Haw.) Walp. Pacific bleeding heart

Epilobium sp. Willowherb

Eriogonum nudum Dougl. ex Benth. Naked buckwheat

Galium aparine L. Stickywilly

Galium multiflorum Kellogg Shrubby bedstraw
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general technical report pnw-gtr-894

Galium oreganum Britton Oregon bedstraw

Galium triflorum Michx. Sweet scented bedstraw

Goodyera oblongifolia Raf. Western rattlesnake plantain

Heuchera micrantha Lindley Small-flowered alumroot

Hieracium albiflorum Hook. White hawkweed

Hypericum perforatum L. Common St. Johnswort

Iris chrysophylla Howell Yellowleaf iris

Lathyrus sp. Pea

Leucanthemum vulgare Lam. Oxeye daisy

Lilium pardalinum Kellogg Leopard lily

Lilium washingtonianum Kellogg Washington lily

Linnaea borealis L. var. longiflora (Torr.) Hultén Longtube twinflower

Listera convallarioides (Sw.) Nutt. ex Elliott Broadlipped twayblade

Lotus crassifolius (Benth.) Greene Big deervetch

Lupinus albicaulis Dougl. Sicklekeel lupine

Lysichiton americanus Hultén & H. St. John American skunkcabbage

Madia sp. Tarweed

Maianthemum racemosum (L.) Link Feathery false lily-ofthe-valley

Mimulus cardinalis Dougl. ex Benth. Scarlet monkeyflower

Mimulus moschatus Dougl. ex Lindl. Muskflower

Mitella breweri A. Gray Brewer’s miterwort

Mitella ovalis Greene Coastal miterwort

Monotropa hypopitys L. Pinesap

Penstemon anguineus Eastw. Siskiyou beardtongue

Piperia elegans (Lindl.) Rydb. ssp. elegans Elegant piperia

Platanthera sparsiflora (S. Wats.) Schltr. var. sparsiflora Sparse-flowered bog-orchid

Prosartes hookeri Torr. Drops-of-gold

Pyrola asarifolia Michx. Liverleaf wintergreen

Pyrola picta Sm. Whiteveined wintergreen

Rumex obtusifolius L. Bitter dock

Sanicula sp. Sanicle

Sarcodes sanguinea Torr. Snowplant

Scoliopus hallii S. Wats. Oregon fetid adderstongue

Senecio triangularis Hook. Arrowleaf ragwort

Senecio vulgaris L. Old-man-in-the-Spring

Streptopus amplexifolius (L.) DC. Claspleaf twistedstalk

Tellima grandiflora (Pursh) Douglas ex Lindl. Bigflower tellima

Thermopsis macrophylla Hook. & Arn. Santa Inez goldenbanner

Tiarella trifoliata L. var. trifoliata Threeleaf foamflower

Tiarella trifoliata L. var. unifoliata (Hook.) Kurtz Oneleaf foamflower

Trientalis borealis Raf. ssp. latifolia (Hook.) Hultén Broadleaf starflower

Trillium ovatum Pursh Pacific trillium

Trillium rivale S. Wats. Brook wakerobin

Veratrum viride Ait. Green false hellebore
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

Vicia americana Muhl. ex Willd. American vetch

Viola glabella Nutt. Pioneer violet

Viola sempervirens Greene Evergreen violet

Xerophyllum tenax (Pursh) Nutt. Common beargrass

Grasses, sedges, and rushes:

Bromus vulgaris (Hook.) Shear Columbia brome

Carex deweyana Schwein. Dewey sedge

Carex hendersonii L. H. Bailey Henderson’s sedge

Carex rossii Boott Ross’ sedge

Elymus glaucus Buckley Blue wildrye

Festuca roemeri Roemer’s fescue

Festuca subulata Trin. Bearded fescue

Glyceria elata (Lam.) Hitchc. Fowl mannagrass

Vulpia sp. Fescue 

Ferns:

Athyrium filix-femina (L.) Roth Ladyfern

Polystichum munitum (Kaulf.) C. Presl Western swordfern

Pteridium aquilinum (L.) Kuhn Western brackenfern

1 Nomenclature for vascular plants, ferns, and fern-allies follows the Flora of North 

America (1993+) and the Oregon Flora Project web site (Cook and Sundburg 2013).

2

 Compiled from field surveys (Lawrence and Kaye 2003, Schuller et al. 2012).
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Appendix 2: Amphibians, Reptiles, Birds, and 

Mammals1 2

Family	 Scientific name	 Common name

Amphibians:

Ambystomatidae Ambystoma gracile Northwestern salamander

Dicamptodontidae Dicamptodon tenebrosus Pacific giant salamander

Rhyacotriton variegatus Southern torrent salamander

Plethodontidae Aneides ferreus Clouded salamander

Ensatina eschscholtzi Ensatina

Plethodon dunni Dunn’s salamander

Plethodon elongatus Del Norte salamander

Salamandridae Taricha granulosa Roughskin newt

Hylidae Pseudacris regilla Pacific chorus frog

Leiopelmatidae Ascaphus truei Tailed frog

Ranidae Rana aurora Red-legged frog

Rana boylii Foothill yellow-legged frog

Rana catesbeiana Bullfrog

Reptiles:

Anguidae Elgaria coerulea Northern alligator lizard

Elgaria multicarinata Southern alligator lizard

Phrynostomatidae Sceloporus graciosus Sagebrush lizard

Sceloporus occidentalis Western fence lizard

Scincidae Eumeces skiltonianus Western skink

Boidae Charina bottae Rubber boa

Colubridae Coluber constrictor Racer

Contia tenuis Sharptail snake

Diadophis punctatus Ringneck snake

Lampropeltis zonata California mountain kingsnake

Pituophis catenifer Gopher snake

Thamnophis atratus Pacific coast aquatic garter snake

Thamnophis couchii Western aquatic garter snake

Thamnophis elegans Western terrestrial garter snake

Thamnophis ordinoides Northwestern garter snake

Thamnophis sirtalis Common garter snake

Viperidae Crotalus viridis Western rattlesnake 

Birds:

Ardeidae Butorides virescens Green heron

Anatidae Aix sponsa Wood duck

Lophodytes cucullatus Hooded merganser

Cathartidae Cathartes aura Turkey vulture

Accipitridae Accipiter cooperii Cooper’s hawk

Accipiter striatus Sharp-shinned hawk

Aquila chrysaetos Golden eagle
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North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

Buteo jamaicensis Red-tailed hawk

Haliaeetus leucocephalus Bald eagle

Pandion haliaetus Osprey

Phasianidae Bonasa umbellus Ruffed grouse

Dendragapus obscurus Blue grouse

Oreortyx pictus Mountain quail

Columbidae Columba fasciata Band-tailed pigeon

Strigidae Aegolius acadicus Northern saw-whet owl

Bubo virginianus Great-horned owl

Glaucidium gnoma Northern pygmy-owl

Otus flammeolus Flammulated owl

Otus kennicottii Western screech-owl

Strix occidentalis caurina Northern spotted owl

Strix varia Barred owl

Caprimulgidae Chordeiles minor Common nighthawk

Phalaenoptilus nuttallii Common poorwill

Apodidae Chaetura vauxi Vaux’s swift

Trochilidae Calypte anna Anna’s hummingbird

Selasphorus rufus Rufous hummingbird

Stellula calliope Calliope hummingbird

Alcedinidae Ceryle alcyon Belted kingfisher

Picidae Colaptes auratus Northern flicker

Dryocopus pileatus Pileated woodpecker

Melanerpes lewis Lewis’ woodpecker

Picoides arcticus Black-backed woodpecker

Picoides albolarvatus White-headed woodpecker

Picoides pubescens Downy woodpecker

Picoides villosus Hairy woodpecker

Sphyrapicus ruber Red-breasted sapsucker

Tyrannidae Contopus borealis Olive-sided flycatcher

Contopus sordidulus Western wood peewee

Empidonax difficilis Pacific-slope flycatcher

Empidonax hammondii Hammond’s flycatcher

Empidonax oberholseri Dusky flycatcher

Hirundinidae Progne subis Purple martin

Tachycineta bicolor Tree swallow

Corvidae Corvus brachyrhynchos American crow

Corvus corax Common raven

Cyanocitta stelleri Steller’s jay

Perisoreus canadensis Gray jay

Paridae Parus atricapillus Black-capped chickadee

Parus rufescens Chestnut-backed chickadee

Aegithalidae Psaltriparus minimus Bushtit

Sittidae Sitta canadensis Red-breasted nuthatch

Sitta carolinensis White-breasted nuthatch
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general technical report pnw-gtr-894

Certhiidae Certhia americana Brown creeper

Troglodytidae Thryomanes bewickii Bewick’s wren

Troglodytes troglodytes Winter wren

Cinclidae Cinclus mexicanus American dipper

Muscicapidae Catharus guttatus Hermit thrush

Catharus ustulatus Swainson’s thrush

Ixoreus naevius Varied thrush

Myadestes townsendi Townsend’s solitaire

Regulus satrapa Golden-crowned kinglet

Turdus migratorius American robin

Bombycillidae Bombycilla cedrorum Cedar waxwing

Vireonidae Vireo cassinii Cassin’s vireo

Vireo gilvus Warbling vireo

Vireo huttonii Hutton’s vireo

Vireo solitarius Solitary vireo

Emberizidae Dendroica coronata Yellow-rumped warbler

Dendroica petechia Yellow warbler

Dendroica nigrescens Black-throated gray warbler

Dendroica occidentalis Hermit warbler

Junco hyemalis Dark-eyed junco

Melospiza melodia Song sparrow

Oporornis tolmiei MacGillivray’s warbler

Passerella iliaca Fox sparrow

Pheucticus meelanocephalus Black-headed grosbeak

Pipilo chlorurus Green-tailed towhee

Pipilo maculatus Spotted towhee

Piranga rubra Western tanager

Spizella passerina Chipping sparrow

Wilsonia pusilla Wilson’s warbler

Zonotrichia leucophrys White-crowned sparrow

Fringillidae Carduelis pinus Pine siskin

Carpodacus purpureus Purple finch

Coccothraustes vespertinus Evening grosbeak

Loxia curvirostra Red crossbill

Mammals: 

Didelphidae Didelphis virginiana Virginia opossum

Soricidae Sorex sonomae Fog shrew

Sorex pacificus Pacific shrew

Sorex trowbridgii Trowbridge’s shrew

Talpidae Neurotrichus gibbsii Shrew-mole

Scapanus orarius Coast mole

Vespertilionidae Antrozous pallidus Pallid bat

Corynorhinus townsendii Townsend’s big-eared bat

Eptesicus fuscus Big brown bat

Lasionycteris noctivagans Silver-haired bat
25

North Fork Silver Creek Research Natural Area: Guidebook Supplement 47

Lasiurus cinereus Hoary bat

Myotis californicus California myotis

Myotis evotis Long-eared myotis

Myotis lucifugus Little brown myotis

Myotis thysanodes Fringed myotis

Myotis volans Long-legged myotis

Myotis yumanensis Yuma myotis

Leporidae Lepus americanus Snowshoe hare

Aplodontidae Aplodontia rufa Mountain beaver

Sciuridae Glaucomys sabrinus Northern flying squirrel

Sciurus griseus Western gray squirrel

Spermophilus lateralis Golden-mantled ground squirrel

Tamias amoenus Yellow-pine chipmunk

Tamias townsendii Townsend’s chipmunk

Tamiasciurus douglasii Douglas’ squirrel

Castoridae Castor canadensis American beaver

Muridae Clethrionomys californicus Western red-backed vole

Microtus longicaudus Long-tailed vole

Microtus oregoni Creeping vole

Microtus townsendii Townsend’s vole

Neotoma cinerea Bushy-tailed woodrat

Neotoma fuscipes Dusky-footed woodrat

Ondatra zibethicus Muskrat

Peromyscus maniculatus Deer mouse

Phenacomys albipes White-footed vole

Phenacomys longicaudus Red tree vole

Dipodidae Zapus trinotatus Pacific jumping mouse

Erethizontidae Erethizon dorsatum Common porcupine

Canidae Canis latrans Coyote

Urocyon cinereoargenteus Common gray fox

Ursidae Ursus americanus Black bear

Procyonidae Bassariscus astutus Ringtail

Procyon lotor Common raccoon

Mulstelidae Martes pennati Pacific fisher

Mustela erminea Ermine

Mustela frenata Long-tailed weasel

Spilogale gracilis Western spotted skunk

Taxidea taxus American badger

Felidae Felis concolor Mountain lion

Lynx rufus Bobcat

Cervidae Cervus elaphus Elk

Odocoileus hemionus ssp. Black-tailed deer 

columbianus

1

 Compiled from habitat descriptions and distribution maps in Csuti et al. 1997.

2

 Nomenclature taken from Csuti et al. 1997. 
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