Click on a habitat area on the transect or on a species on the photograph to see more. Photos of this habitat 1 2

The desert scrub forest region lies primarily between the Rocky Mountains and the Cascade-Sierra mountain system. It is sometimes referred to as the intermountain region. Desert scrub vegetation occurs where summer rainfall is insufficient to support large trees or closed-canopy forests. Eastward moving air coming down the eastern flanks of the Sierra and Cascade Mountains loses its moisture to those mountains and doesn't become cool enough to allow frequent precipitation until it encounters the high Rocky Mountains. Sagebrush dominated vegetation then gives way to mountain conifers. Permanent streams, fed by mountain snow and summer rain support western species of cottonwood, willow, sycamore, and other deciduous vegetation. The snow in this photo is a reminder that the desert scrub region has cold winters.