SOIL SURVEY

-75-The silty surface texture, slow permeability, and susceptibility to frost-heavingsuggests that this map unit has moderate and severe limitations for most recreationa land engineering uses .FL - Float Soilscape GroupPhysiographic Setting (Figure 84 )Members of the Float soilscape group occur on steeply sloping (30 to 60% )colluviated mountain sides, generally well above the valley floor .Landform and Parent Material sMembers of the Float soilscape group occur on similar landform positions tothe Burgess soilscape group (Figure 23), especially BG 3, except that for variou sreasons the soils of the Float soilscape group are stable enough to allow the developmentof distinct horizons . In general the increased stability appears to occu rwhere no rock cliff is above the land unit to provide a continuous increment o fgravity transported material each year . However, gravity transported material sprovide the parent material for the soils so catastrophic events such as fires mus thave allowed unstable periods of colluvial transport .EnvironmentFloat soilscape groups occur on well drained sites in the subalpine an dmontane vegetative zones at elevations ranging from valley bottom to about 200 0m a .s .I .FL1 Map Unit (Orthic Eutric Brunisols and Orthic Humo-Ferric Podzols )This map unit is characterized by soils which occur on colluvium at elevation sbelow the forest-alpine ecotone and which have brownish and reddish B horizo ndevelopment . These soils are medium to coarse textured, generally contain 10 t o30% coarse fragments and are well drained . The relatively stable soils of this ma punit probably result from the lack of cliffs which supply a constant source of new