Elba, Cassia Co., Idaho, June 17 in the areas covered since we left Payette are: Emmett Valley - Lower Sonoran - the dominant plants were Cottonwoods and Atriplex - The area bordering the Snake River from Payette east to Minidoka dam at least is also Lower Sonoran, however from Twin Falls on each there are few Cottonwoods. The whole areas between the river and the mountains to the north and to the south is Upper Sonoran - Artemisia tridentata being the dominant plant. However, this plant is also found - stunted in growth - higher on the mountains. The Transition Life-zone is found in the canyons on the mountains to some extent, but here we find Canadian on the North facing slopes and Upper Sonoran on the south facing slopes, the bottom of the canyon usually being a mixture of the two. Indicators in the way of birds and mammals are few if any because the size of the area,