This report presents July 1988 water quality data, principally dissolved nitrite plus nitrate (as nitrogen), and depth-to-water measurements for 60 wells in the Fort Hall Indian Reservation north of Pocatello, southeastern Idaho. Nitrogen concentrations ranged from 0.7 to 24 mg/L; the median concentration was 3.1 mg/L. Nitrogen concentrations in 11 samples exceeded the U. S. Environmental Protection Agency public drinking water limit of 10 mg/L. (USGS)