Cercocarpus ledifolius communities of Utah were sampled to determine which measured environmental characters were influential in determining community structure and dynamics. Nineteen, one-tenth acre stands were sampled by 25 equally spaced .25m2 quadrats. Plant frequency, cover, density, height, diameter, age, elevation, slope and exposure were determined for curl-leaf mahogany within the study area. Soil depth and soil samples were analyzed for texture, pH and soluble salts. Curl-leaf mahogany is found almost entirely on arid rocky slopes, canyon ledges, and plateaus at relatively high elevations on all exposures. The soils were invariably shallow and slightly acidic with sandy loam soils being most common. Soluble salts were low in all the soils analyzed. Over 90 percent of the prevalent species were perennial in habit. Reproduction of curl-leaf mahogany was considered poor. Elevation, soluble salts, soil pH, exposure and percent silt in the soil together accounted for 74 percent of the variation observed in the site quality index computed for curl-leaf mahogany in the communities sampled.