Wind/Bighorn River Basin - Study Area
The WBRB drainage basin covers approximately 25 percent of the state in north-central and northwestern Wyoming, plus smaller areas of south-central Montana. Figure 3-1 is an index map of the approximately 678 townships within the WBRB in Wyoming (625) and Montana (53). As determined from the GIS database developed for this study, the WBRB covers approximately 22,883 square miles (14.65 million acres) in Wyoming and 894 square miles (0.57 million acres) in Montana. The WBRB encompasses federal, state, and privately owned land in all or part of eight Wyoming counties:
- All of Big Horn, Park, and Hot Springs counties
- Approximately 95 percent of Washakie County
- Approximately 85 percent of Fremont County
- Approximately 10 percent of Teton County
- Small, relatively undeveloped parts of northwestern Natrona and western Johnson counties
Approximately 80 percent of Yellowstone National Park (in Park and Teton counties) is included in the drainage basin, as is the Wind River Indian Reservation (Fremont and Hot Springs counties). The northern WBRB (Bighorn Basin) includes small areas of Park, Sweet Grass, Carbon, and Big Horn Counties in south-central Montana.
The current population of the Wyoming WBRB is estimated to be 89,500 (MWH, 2010). The WBRB has a substantial rural population.