The Harquahala Basin, located in the northeastern part of the planning area, is 766 square miles in area. Geographic features and principal places are shown on Figure 7.3-1. The basin is characterized by a plain bordered by mountain ranges. Vegetation types include Lower Colorado River Valley and Arizona uplands Sonoran desertscrub and a small amount of southwestern interior chaparral on the northern basin boundary. (See Figure 7.0-9)
Principal geographic features shown on Figure 7.3-1 are:
- Centennial Wash running through the center of the basin
- The Harquahala Plain in the center of the basin bordered by the Big Horn Mountains in the east, the Little Harquahala Mountains in the north and the Eagletail Mountains in the west
- The highest point in the basin, Big Horn Peak, at 3,480 feet in the Big Horn Mountains
- The lowest point in the basin at 1,000 feet where Centennial Wash exits the basin in T4N R12W.
Figure 7.3-1 Harquahala Basin Geographic Features