The Toshingermann Lakes map area straddles the northwestern extent of the Ruby and Nisling ranges. Broad treeless uplands dominate the landscape and summits reach more than 1800 m above sea level. Upland surfaces are covered with weathered bedrock colluvium and sporadically distributed till deposits from alpine glaciers and ice sheets. Upland surficial deposits are affected by active periglacial processes such as cryoturbation, nivation and solifluction.