Observations on the Nisqually glacier, Washington and Grinnell, Jackson, and Sperry Glacier, Montana

Data collected during various periods back to 1857 on the terminal recession, changes in surface elevation, and surface movement of these glaciers are discussed. Nisqually Glacier receded about 4900 feet since 1857 at an average rate of 50 feet per year. The surface elevation has risen 83 feet between 1945-51. Other detailed data is included since more interest has been shown in glacier activity. Little change has been observed in Sperry and Grinnell although Grinnell has retreated 30 to 40 feet per year since 1949. Sperry is considerably less active.