Increasing destruction of natural habitat in the United States due to growing population has resulted in a series of laws, policies, and guidelines designed to protect and better manage natural resources. Garden Canyon, located in the pine and oak-covered Huachuca Mountains in the southern part of the Fort Huachuca Military Reservation (Figure 1), contains many plant and animal species that are federally listed or are candidates for listing as threatened or endangered. The geomorphology and surficial geology of Garden Canyon were assessed through interpretation of aerial photographs and soil maps and extensive fieldwork. Color aerial photography (1:23,000 scale) and Soil Conservation Service soil maps were used to distinguish geologic surfaces. Geomorphic surfaces of different ages and landform type were distinguished and mapped using criteria such as topographic position, degree of stream dissection, degree of surface clast weathering, and soil development (see Bull, 1991). Map unit boundaries and surface correlations were then field checked. Age estimates for the different surfaces are based on correlations to surfaces with similar weathering and soil characteristics that have radiometric age control and are located in the lower Colorado River Valley (Bull, 1991) and middle Rio Grande Valley (Gile et al., 1983).