The Cache Creek HBN Basin is in the Middle Rocky Mountains physiographic province (Fenneman, 1946) in western Wyoming (Figure 24. Map showing study area in Cache Creek Basin and photograph of the landscape of the basin). The HBN station is 3.9 km southeast of the town of Jackson, Wyo., at a latitude of 43×27'08'' and a longitude of 110×42'12''. Cache Creek drains about 27 km2 of steep mountain and canyon terrain in the Gros Ventre Mountains. Basin elevations range from about 2,100 to about 3,100 m. The ecoregion of the basin is classified as the Southern Rocky Mountain Steppe-Open Woodland-Coniferous Forest-Alpine Meadow Province (Bailey, 1995). Timber covers about 80 percent of the north-facing slopes and 50 percent of the south-facing slopes. On the south-facing slopes, subalpine fir, lodgepole pine, and Engelmann spruce are the dominant timber species. Subalpine fir, Douglas fir, and lodgepole pine timber species dominate the north-facing slopes. Grass, forbs, and brush cover the remaining area up to timberline. Underbrush includes mountain big sagebrush, whortleberry, huckleberry, and pinegrass (Sandra Key, U.S. Forest Service, written commun., 1997). Cache Creek is tributary to Flat Creek, which is tributary to the Snake River.