Physiographic features

Topography of the site is gently rolling hills. It occurs on hillsides, sideslopes, and toeslopes. The site occurs on south slopes at the higher elevations and north facing slopes at the lower elevations. Slopes can range from 5 to 20 percent. Elevation is between 6800 and 8000 feet.

Table 2. Representative physiographic features

Climatic features

Average annual precipitation is about 12 to 16 inches. Of this, approximately 45-55% falls as snow, and 45-55% falls as rain between middle of May to and the end of September. Summer moisture is mostly from thundershowers in July thru October. November to February and June is the driest period of the year with the driest month being June. August to October and March to April is the wettest period and the wettest month is usually April. The average annual total snowfall is 64.8 inches. The snow depth usually ranges from 1 to 5 inches during October thru April. The highest winter snowfall record in this area is 131.9 inches which occurred in 1908-1909. The lowest snowfall record is 11.9 inches during the 1944-1945 winter. The average growing season is about 140 days. Native plants green up about May 15th. Active growth continues through July 1. Plants are usually dormant by mid-October. The frost-free period typically ranges from 90 to 130 days. The last spring frost is typically the middle of May to the second week of June. The first fall frost is usually the middle of September to the end of September. Mean daily annual air temperature ranges from about 30.7ºF to 64.8ºF, averaging about 25ºF for the winter and 66ºF in the summer. Summer high temperatures of mid-80ºF to low 80ºF are not unusual. The coldest winter temperature recorded was -36ºF on February 8, 1933 and the warmest winter temperature recorded was 66ºF on February 11, 1962. The coldest summer temperature recorded was 24ºF on June 19, 1973 and the warmest was 100ºF on August 2, 1902. Wide yearly and seasonal fluctuations are common for this climatic zone. Data taken from Western Regional Climate Center (2018) for Collbran, Colorado Climate Station.

Other:
Relative humidity in areas where this site occurs is usually very low (10 percent). Since much of the summer precipitation comes in the form of light showers, much of it evaporates before it becomes effective to the native plants.


This zone in MLRA 48 will need to be broken up into at multiple land resources zones in future projects based on current knowledge of precipitation and temperature patterns.

West Central Zone Stations: Collbran, Basalt, and Cedaredge. This LRU zone is use in write up above. November to February and June is the driest period of the year with the driest month being June. August to October and March to April is the wettest period and the wettest month is usually April. Frigid

Northwest Zone Climate Stations: Meeker#2. Driest months usually are January and February. Wettest months usually are August and September. Frigid.

Southwest Zone Climate Stations (Precambrian sedimentary and igneous): There are no climate stations in this LRU zone.

Southwest Volcanics: Lake City, Creede, and Hermit 7 ESE. These high elevation and low precipitation areas are cryic with shorter growing season days of 20 to 70 days per year. Wettest months are August and July. Driest months are December thru February.

Northeast (Front Range Igneous and Metamorphic): Grant, Estes park, Hohnholz Ranch, Leadville and Leadville 2 SW. July and August are the wettest months. January is the driest month. The climate stations is this zone are cryic. The growing seasons is 50 to 90 days.

Southeast (Sangre de Cristo Mtns): Westcliffe. Red Wing 1 WSW and Sheep Mountain. The growing season is 90 to 140 days. Driest months are December to February and the wettest are July & August. Frigid.

Table 3. Representative climatic features

Climate stations used

• (1) CIMARRON [USC00051609], Cimarron, CO

• (2) CEDAREDGE 3 E [USC00051443], Cedaredge, CO

• (3) COLLBRAN [USC00051741], Collbran, CO

Influencing water features

None

Soil features

Soils are deep to very deep and well drained. Surface texture is loam. Soft shale is at 22 to 60 inches (56 to 152 cm). Soils are dark colored originating from the shale parent material (Wasatch Formation). Soils are not well developed and have a strong shale influence.

Soils correlated to this site:

Emmons

Table 4. Representative soil features

Animal community

INTERPRETATIONS FOR GRAZING ANIMALS:
This site has limited value for grazing of livestock due to low production of the native species. Proper grazing use and a planned grazing system are conservation practices which very much help to improve range condition. The species are a variety of grasses and shrubs that provide good nutrition for grazing animals. Continuous year-long grazing or grazing from mid-May to mid-October by cattle cause the most desirable grasses to decrease and be replaced by in increase in forbs, shrubs, and invaders. A system of deferred grazing, which varies the season of grazing in pastures during successive years, is needed to maintain a healthy well-balanced plant community. Rest during different seasons of the year benefits different plants. Fall and winter rest (September-October) benefits shrubs such as rabbitbrush and mountain big sagebrush. Spring rest (mid-May through early July) benefits cool-season plants such as western wheatgrass, and prairie Junegrass. Deferment during late winter and spring reduces competition between grazing animals for palatable shrubs and forbs.

INTERPRETATIONS FOR WILDLIFE:
South facing slopes at lower elevations of this site are often considered critical big game winter range. Higher elevations are particularly important as elk winter range. Nuttall’s cottontail, white-tailed jackrabbits, Richardson’s ground squirrel, sage grouse, Brewers sparrow, and sage sparrow can also be found on this site. Where the site is adjacent to cliffs and/or large trees, it can be an important component of golden eagle, red-tailed hawk, and American kestrels habitat.

Hydrological functions

Soils in this site are grouped into “C” hydrologic group, as outlined in the “Soils of Colorado Loss Factors and Erodibility Hydrologic Groupings 1979” handbook. Field investigations are needed to determine hydrological cover conditions and hydrologic curve numbers. The hydrologic curve number for Group “C” soil is about 78 for all the soils except the Aaberg series which is Group “D” with a hydrologic curve number of 83 when hydrologic conditions are good, as shown in “Peak Flows in Colorado” handbook.

Refer to SCS National Engineering Handbook, Section 4, to determine runoff quantities from the curves.

Recreational uses

RECREATION AND NATURAL BEAUTY:
The site is good habitat for big game, upland game birds, rabbits, and coyotes. Therefore, hunting is a form of recreation which can take place on the site. This site receives enough snow to make good conditions for cross country skiing and snowmobiling.

Wood products

Utah juniper can be an invader on this site. If a thick stand of juniper becomes established, the trees can be cut for firewood and posts. By cutting these invading trees, the understory production can be increased.

Other information

ENDANGERED PLANTS AND ANIMALS:
(Species names to be included as reliable information becomes available).

MAJOR PLANTS POISONOUS TO LIVESTOCK THAT MAY CAUSE POISONING:
Greasewood is poisonous in the spring. Cattle and sheep are affected.
Effects and symptoms:
Poisoning is “acute”. Early signs of poisoning (4-6 hours after animals eat toxic amounts) are dullness, loss of appetite, lowering of the head, reluctance to follow the band and irregular gait. Advanced signs are drooling, nasal discharge, progressive weakening, rapid shallow breathing, and coma. Cattle may die after eating 3 to 3.5 pounds in a short time.

Halogeton is poisonous when growing rapidly in spring (April-June). Sheep are affected.
Effects and symptoms:
Poisoning is “acute”. Signs of poisoning occur in 2 to 6 hours after an animal eats a fatal amount and death occurs in 9 to 11 hours. Early signs are dullness, loss of appetite, lowering of the head, and reluctance to follow the band. Advanced signs are drooling with white or reddish froth about the mouth, Progressive weakening, animals unable to stand, rapid and shallow breathing, and coma followed by violent struggle for air.

Twogrooved milkvetch is poisonous year long especially in the spring. All livestock are affected.
Effects and symptoms:
Poisoning is “accumulative.” Signs of poisoning are rough coat, abnormal growth of long mane and tail hair, lack of coordination of muscles, constipation, and a peculiar gait.

Utah juniper
Utah juniper can only be poisonous to cattle when desirable forage is not available. Death loss from this species is rare. Stock may be poisoned if large quantities of berries are eaten.

GUIDE TO INITIAL STOCKING RATES 2/
Condition % Climax
Class Vegetation Ac/AUM AUM/Ac Ha/AUM AUM/Ha
Excellent 76-100 20 .05 8.1 .12
Good 51-75 25+ .04 10.1 .10
Fair 26-50 - - - -
Poor 0-25 - - - -
2/Stocking rates are based on an average growing season. Based on 1200 pounds (540Kg) of forage (air-dry) per animal unit month. (This figure takes into account the vegetation that disappears through trampling, small herbivores, etc., which amounts to approximately 7.9 pounds (3.6Kg) per day under normal conditions).

LOCATION OF TYPICAL EXAMPLES OF THE SITE:
Field offices where the site occurs areEagle and Kremmling.

Type locality

Other references

Chapman, S.S., G.E. Griffith, J.M. Omernik, A.B. Price, J. Freeouf, and D.L. Schrupp. 2006. Ecoregions of Colorado. (2 sided color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey, Reston, VA. Scale 1:1,200,000.

Cleland, D.T.; Freeouf, J.A.; Keys, J.E.; Nowacki, G.J.; Carpenter, C.A.; and McNab, W.H. 2007. Ecological Subregions: Sections and Subsections for the conterminous United States. Gen. Tech. Report WO-76D [Map on CD-ROM] (A.M. Sloan, cartographer). Washington, DC: U.S. Department of Agriculture, Forest Service, presentation scale 1:3,500,000; colored.

Natural Resource Conservation Service (NRCS). April 2011. ESIS Range Site Description for Dry Mountain Shale #242: USDA, Denver Colorado

United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.

Western Regional Climate Center. Retrieved from http://www.wrcc.dri.edu/summary/Climsmco.html on Decenber 10, 2018

Contributors

Jim Kellogg
Suzanne Mayne-Kinney

Approval

Kirt Walstad, 3/05/2024

Acknowledgments

Project Staff:
Suzanne Mayne-Kinney, Ecological Site Specialist, NRCS MLRA, Grand Junction SSO
Chuck Peacock, MLRA Soil Survey Leader, NRCS MLRA Grand Junction SSO

Program Support:
Rachel Murph, NRCS CO State Rangeland Management Specialist, Denver
Scott Woodhall, NRCS MLRA Ecological Site Specialist-QA Phoenix, AZ
Eva Muller, Regional Director, Rocky Mountain Regional Soil Survey Office, Bozeman, MT
B.J. Shoup, CO State Soil Scientist, Denver
Eugene Backhaus, CO State Resource Conservationist, Denver

Those involved in developing earlier versions of this site description include: Bob Rayer, retired NRCS Soil Scientist; Herman Garcia, retired CO State RMS and NRCS MLRA Ecological Site Specialist-QA Phoenix, AZ.

--Site Development and Testing Plan--:

Future work to validate and further refine the information in this Provisional Ecological Site Description is necessary. This will include field activities to collect low-, medium-, and high-intensity sampling, soil correlations, and analysis of that data.

Additional information and data is required to refine the Plant Production and Annual Production tables for this ecological site. The extent of MLRA 48A must be further investigated.

Field testing of the information contained in this Provisional ESD is required. As this ESD is moved to the Approved ESD level, reviews from the technical team, quality control, quality assurance, and peers will be conducted.