A mineral-resource survey of the Boulder-Pioneer Wilderness study area in the Pioneer and Boulder Mountains of south-central Idaho, was made. The area has demonstrated resources of about 1. 7 million tons of lead-zinc-silver ore, mostly in the Phi Kappa mine, and an additional 2. 5 million tons of demonstrated resources in areas of substantiated potential for these metals and for tungsten, molybdenum, and fluorite. The survey indicates substantiated resource potential in eight areas and probable mineral-resource potential in seven. Mineral commodities of greatest intertest include tungsten, copper, lead, zinc, silver, gold, molybdenum, vanadium, and barite. There is little likelihood for the occurrence of oil, gas, coal, or geothermal resources.