Drainage density of southern California desert mountains by Wayne N. Engstrom, Bull. Southern California Acad. Sci., 82(3): 1 15-124. 1983. Measurements made in a systematic fashion from topographic maps reveal that the drainage density of 68 third order drainage basins located in three mountain ranges in the deserts of southern California averages 14.6 km/km<sup>2</sup>. The drainage density of the El Paso Mountains is significantly lower than that of the Bullion and Chemehuevi Mountains. A preliminary inquiry suggests that variations in climate/vegetation conditions and in relief age may be linked to this difference. Relief ratio does not appear to significantly influence drainage density in the study ranges but the possible influence of rock type needs to be assessed.