This report presents a selected bibliography of water quality studies covering the upper Gila River watershed and discusses a few ofthe more important publications. Previously unpublished water quality data are reported for the Gila River and groundwater in the Safford basin. References cover the Gila River watershed between the Arizona-New Mexico border on the east and Coolidge Dam on the San Carlos Indian Reservation on the west. The watershed includes roughly 11,470 square miles, about half in Arizona and half in New Mexico. The Gila River enters Arizona near the town of Duncan and flows to the northwest through the Duncan basin, then cuts across the northern Peloncillo Mountains to enter the middle of the Safford-San Simon Valley east of Safford. After flowing northwest to the north end of the Safford basin the river turns southwest, exiting the basin through a bedrock gorge cut at right angles to the Mescal and Dripping Spring Mountains. The geologic history of the upper Gila region controls the hydrology and the chemistry of surface water and groundwater in the watershed. Both the Duncan and Safford basins are deep, sediment-filled structural troughs containing abundant lacustrine (lake) and playa sediments, reflecting long periods of closed-basin conditions (Harris, 1997). Soluble minerals such as halite, carbonates, gypsum, and anhydrite are common in the basin-fill sediments and contribute significant TDS to the groundwater of the basins and to the Gila River (Harris, 1999). ( 67 pages)