SOIL SURVEY

-145-The stoniness and periodic snow avalanching which are generally associate dwith this map unit result in a very severe limitation for most recreational and engineeringuses .WR 3 Map Unit (Orthic and Cumulic Regosols )This map unit is characterized by those soils which have developed o ncalcareous, stratified, gravelly to very gravelly fan alluvium overlain by mediu mtextured deposits . Silt loam and fine sandy loam textures with about 5% coarsefragments are common in the medium textured surficial deposit while gravelly sand yloam and gravelly loamy sand textures are common in the lower horizons . Thes esoils have weak horizon development although a thin (less than 5 cm thick) B mhorizon is sometimes present .Table 55 . Brief description of the pedon chosen to characterize the WR3 map unit .HorizonL-F 3-0Depth Moist Color(cm)Est . Coars eFragments Textur e(%)very dark brown; partially decomposedneedles and leave sAe 0-1 gray not sample dpH(CaCI 2)Organi cMatter(%)6 .0 47ACk 1-4 brown < 5 sandy loam 7 .2 1 4Ckl 4-40 light gray < 1 silt loam 7 .3 trac every gravell yCk2 40-90 gray 60 loamy coarse 7 .2 trac esandCk3 90-110+ pale olive 10 silt loam trac eOrthic Regoso lThe generally silty surficial texture results in moderate limitations for mos trecreational uses . In addition, the Regosolic nature of these soils suggests that the yare subject to occasional stream channel shifting and/or overland flow during sprin grunoff .