Kaufman, Clark Co., Idaho. June 27, On June 20, in the A.M. I made up skins until about 11:00, at which time I began hunting for Marmots in a rocky outcropping on the shore of the American Falls Reservoir about 4 mi. W E of American Falls. They were plentiful and were doing considerable damage to a crop of wheat which was nearby. They had sheared off a strip about 75 ft. wide along the edge bordering on the reservoir. Marmots do not reach maturity, that is full size the first - nor the second year - I believe. In this colony young of the year, many that were sexually mature, I believe, but only about 2/3 the size of the largest ones. I collected 3 - 1 old ♀ and two about 2/3 grown. The latter were discarded. The color of these small ones was identical with that of the one collected. In this same rocky situation I saw one Sylvilagus nuttallii; also a weasel. The latter was collected. It was first seen emerging from a crevice in the rocks, and catching sight of me it immediately retreated