ALPINE SOILS OF THE ROCKY MOUNTAINS1

Abstract

Summary: A field and laboratory study was made of soils developed in the alpine region of the Rocky Mountains. The region is a grassland above the general elevations of 10,500 ft. in Wyoming, 11,500 ft. in southern Colorado. Cold inhibits soil development.Three groups of soils occur. Their gross characteristics are determined by drainage and variations in parent rocks from which the soils developed. The groups are described and given the names of Alpine Turf, Alpine Meadow, and Alpine Bog soils.Only the Alpine Turf soils were studied in the laboratory. They are characterized by an organic‐carbon content of 5–20 per cent. in the surface 5–7 in. and coarse, gravelly, or sandy textures throughout. The largest amounts of sift and clay occur in the surface. The range in pH is from 4.5 to 8.4, depending on the kind of parent rock, but no marked variations occur in any horizon of any soil. Preliminary studies revealed the presence of some of the common clay minerals in the fine soil fractions. This was taken as evidence that these soils are starting on the nonnal course of soil development. The morphology is simple, consisting of an A‐B‐C profile. Horizons are more distinct in the turf soil than in either the meadow or bog soils.