The results of geologic, geochemical, aeromagnetic, and mine and prospect investigations define the mineral-resource potential of the Eagle Rock Roadless Area of north-central Washington. The area has probable and substantiated resource potential for base and precious metals where the eastern part of the Index mining district extends into the roadless area; the Sunset mine, 400 ft outside the area, has inferred copper resources, and 10 other properties in the roadless area have demonstrated resources for base and precious metals. The resource potential in the area is related to the Index batholith, which makes up the western part of the roadless area, and rocks to the east in the roadless area that are intruded by the Index batholith. There is little promise for the occurrence of energy resources in the roadless area.