This map is one in a series of 1:500,000-scale geologic maps prepared to investigate areas on Mars of high scientific interest. The quadrangle contains the source area for Mangala Valles, one of the largest outflow channel complexes on Mars (Sharp and Mali, 1975). Preliminary mapping by Masurksy and others (1986), Simbelman (1988), and Champlan and others (1989, 1991) showed that several episodes of channel formation and deposition may have occurred in association with Mangala Valles. To elucidate the complex history Mangala Valles and the general geology of the area surrounding their source, the detailed photogeology of the MTM -20147 quadrangle is presented here.