The Bureau of Mines conducted laboratory studies on low-grade vanadiferous silicates from the Pumpkin Buttes and Nine Mile Lake deposits of Wyoming to examine techniques for extracting vanadium and uranium. Recovery from low-grade sources such as these could contribute to future vanadium production and reduce reliance on vanadium imports. The Pumpkin Buttes samples contained 0.03 to 0.04 pct v2o5 and 0.06 to 0.12 pct u3o8; the Nine Mile Lake samples contained 0.02 to 1.0 pct v2o5 and 0.06 to 0.19 pct u3o8. Leaching the Pumpkin Buttes samples for 18 h at 80 deg c with addition of 200 lb/ton h2so4 resulted in recovery of 80 pct of the vanadium contained in the samples. The Nine Mile Lake samples were readily leached, yielding 78 to 94 pct of the vanadium after 3 h at 80 deg c. With addition of 100 lb/ton h2so4. A solvent extraction procedure was used to selectively recover uranium from Pumpkin Buttes and Nine Mile Lake leach solutions and to recover vanadium from the raffinates. In batch shakeout tests, alamine 336 recovered over 95 pct of the uranium from leach solution adjusted to ph 1. Di- 2-ethylhexyl phosphoric acid and cyanex 272 recovered vanadium from the uranium raffinate after reduction and adjustment to ph 2; vanadium extractions of up to 96 pct and 92 pct, respectively, were achieved.