Physiographic features

Physiographic Features
Landscapes: Mountains
Landforms: Mountain slope, ridges

Elevation:
Total range = 1285 to 2145 m;
(4,215 to 7,040 feet)
Central Tendency = 1605 to 1825 m
(5,265 to 5,985 feet)

Slope:
Total range = 0 to 90 percent
Central Tendency = 30 to 55 percent

Aspect: Total range = 40-195-310
Central tendency = 130-195-235

Table 2. Representative physiographic features

Table 3. Representative physiographic features (actual ranges)

Climatic features

Climatic Features

During the spring and summer, a circulation of air around a high-pressure center brings a prevailing westerly and northwesterly flow of comparatively dry, cool and stable air into the region. As the air moves inland, it becomes warmer and drier which results in a dry season beginning in the late spring and reaching a peak in mid-summer. In the fall and winter, a circulation of air around two pressure centers over the ocean brings a prevailing southwesterly and westerly flow of air into the Pacific Northwest. This air from over the ocean is moist and near the temperature of the water. Condensation occurs as the air moves inland over the cooler land and rises along the windward slopes of the mountains or highlands. This results in a wet season beginning in October, reaching a peak in winter, then gradually decreasing in the spring.

Temperature
The pattern of average annual temperatures indicates the effect both of latitude and altitude. In general, it can be said that monthly means are 32° F or lower at stations above 5,000 feet from November through March; between 4,000 and 5,000 feet, November through February; 3,000 to 4,000 feet, December through February; and 2,000 to 3,000 feet, only one or two months. The diurnal range of temperature is, of course, most extreme in high valleys and in the semiarid plains. The magnitude of diurnal range varies with the season, being lowest in winter when cloudiness is much more prevalent, and greatest in the warmer part of the year. In summer, periods of extreme heat extending beyond a week are quite rare, and the same can be said of periods of extremely low temperatures in winter. In both cases the normal progress of weather systems across the region usually results in a change at rather frequent intervals.

Precipitation
To a large extent the source of moisture for precipitation regionally is the Pacific Ocean. In summer there are some exceptions to this when moisture-laden air is brought in from the south at high levels to produce thunderstorm activity. Seasonal distribution of precipitation shows a very marked pattern of winter maximum and midsummer minimum.



Snowfall
Snowfall distribution is affected both by availability of moisture and by elevation. Annual snowfall totals have reached nearly 500 inches. The major mountain ranges accumulate a deep snow cover during the winter months, and the release of water from the melting snowpack in late spring is a primary source of instream flows.
(from WRCC: Climate of Idaho)

Frost-free period (days):
Total range = 65 to 110 days
Central Tendency = 80 to 95 days

Mean annual precipitation (cm):
Total range = 750 to 2635 mm
(29 to 104 inches)
Central Tendency = 1220 to 1855 mm
(48 to 73 inches)

MAAT (C)
Total range = 1.9 to 6.5
(35 to 44 F)
Central tendency = 3.3 to 4.6
(38 to 40 F)

Climate stations: none

Influencing water features

Water Table Depth: >80 inches

Flooding:
Frequency: None
Duration: None

Ponding:
Frequency: None
Duration: None

Soil features

Representative Soil Features

This ecological site is associated the soil components Typic Fulvicryands, Brickel, and Joebaldy. These components are classified as Typic Fulvicryands, Vitrandic Haplocryolls, and Humic Vitricryands. These soils have developed in mixed Mazama tephra deposits over colluvium and residuum derived from granitic, metamorphic, or metasedimentary rock. Soils are generally moderately deep to bedrock, skeletal and have low to moderate available water holding capacity.

Table 4. Representative soil features

Table 5. Representative soil features (actual values)

References

• Gregory, S. 1983. Subalpine forb community types of the Bridger-Teton National Forest, Wyoming. Final Report. USDA Forest Service Cooperative Education Agreement: Contract OM 40-8555-3-115.. USDA Forest Service, Intermountain Region, Ogden, UT. 1–97.

• Johnson, D.H. and T.A. O’Neil. 2001. Wildlife-Habitat Relationships in Oregon and Washington. Oregon State University Press, Corvallis, OR.

• Rocchio, J.F. and R.C. Crawford. 2015. Ecological systems of Washington State. A guide to identification. Washington Department of Natural Resources.. Natural Heritage Report.. Washington Department of Natural Resources, Natural Heritage Program, Olympia, WA. 1–397.

Approval

Curtis Talbot, 10/15/2020