Ground-water data for the Baker County-northern Malheur area, Oregon, are tabulated for the Bureau of Land Management. The data include well and spring records, a well-location map, drillers' logs of wells, observation-well hydrographs, and chemical analyses of ground-water samples. The reported yields of wells and springs in the area ranged from less than 1 to 2,500 gallons per minute. Dissolved solids in ground-water samples ranged from 50 to 1,587 milligrams per liter, and arsenic ranged from 0.001 to 0.317 milligrams per liter.