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J UNITED STATES DEPARTMENT OF AGRICULTURE Soil Conservation Service, Colorado C~ Technical Guide RANGE SITE N0. 241 Section II E Field Office August 1975 RANGE SITE DESCRIPTION for MOUNTAIN MEADOW Land Resource Area: Southern Rocky Mountains (48) A. PHYSICAL CHARACTERISTICS 1. Physiographic Features The site occurs in mountain valleys, swales, parks, and around potholes. Topography is nearly level to fairly steep. There may be slight irregularities, but the terrain is generally smooth. Slopes are mostly 0 to 3$, but are steeper In a few places. They have no significant influence on plant growth. Elevation ranges from about 7000 feet to 11,500 feet. 2. Climatic Features Average annual precipitation is mostly from 15 inches to more than 40 inches, half or more coming in the form of snow. How- ever, the key to existence of the site is natural subirrigation in a cool mountain climate, rather than amount of precipitation. The site may therefore exist•on drier areas (down to about 10 inches annual precipitation) where summers are short and cool enough. Major native plants start their main growth from mid-May to early June and continue through mid-July or August. The growing season varies because of the wide range in elevation over which the site occurs. Mean annual temperatures range from about 30° to 44° F. Average frost-free period is less than 50 days and may be extremely short at upper elevations. It is about 100 days at Lowest elevations. Evaporation rates are moderate to low. There is snow cover through winter and early spring (often into late spring at some locations). Some plants start growth under the snow and develop rapidly following snowmelt. This, with a low or non-existent moisture deficit, seems to favor certain characteristic plants that are scarce or absent on similarly wet soils in drier climates.