Three-Bar Wildlife Area

Description and History

The research program on the Three-Bar watersheds represented the first major experimental watershed program in Arizona chaparral shrublands (DeBano et al. 1999a). Four watersheds (A, B, C, and D) were established and instrumented in 1956 on the Three-Bar Wildlife Area west of Lake Roosevelt. This area supported dense chaparral stands and had not been grazed since 1947. All of the watersheds were burned by a wildfire in June of 1959. After the burn, watershed A was abandoned, and watershed F, was instrumented in June 1963 to replace it. All four watersheds (B, C, D, and F) are north-facing, at elevations of 3,350 to 4,250 ft, on soils derived from granite, with the upper slopes exceeding 70%.

After a wildfire

Previous studies on chaparral had been conducted at the Natural Drainages on the Sierra Ancha Experimental Forest (see above). However, the Three-Bar location, provided a better opportunity for evaluating maximum water yields that might be expected from shrub-to-grass conversions, because of its higher yearly precipitation and dense chaparral cover (greater than 60% crown cover). The dense stands were highly productive areas. Experimental watersheds were subsequently established in medium density chaparral (40 to 60%) on the Whitespar watersheds, and low density cover (less than 40%) on the Mingus watersheds. These watersheds are in north-central Arizona (Yavapai County), in the Central Arizona Highlands (DeBano et al. 1999b). The range of densities at Three-Bar, Whitespar, and Mingus were representative of most of Arizona's chaparral shrublands, and allowed researchers and managers to better identify chaparral shrublands which could be economically treated to obtain increased streamflow.

Cooperators

Interest in chaparral management evolved into a research and management program involving several agencies and organizations. The Tonto National Forest was responsible for managing much of the chaparral areas in the Central Arizona Highland. USDA Forest Service research was conducted by the Rocky Mountain Forest and Range Experiment Station and was assigned to the Forestry Science Laboratory at Tempe. Most of the Forest Service research addressed hydrologic and vegetative evaluations. Scientists with the Arizona Game and Fish Department provided wildlife evaluations on the Three-Bar Wildlife Area. Cooperative studies were also carried out with the University of Arizona, Arizona State University, and Colorado State University. Personnel from the Salt River Project and Arizona Water Resources Committee provided support and guidance in many of the watershed evaluations. Streamflow was gaged on some watersheds by the U.S. Geological Survey of the Department of Interior.

The information in this section is excerpted from History of Watershed Research in the Central Arizona Highlands