A technique has been developed utilizing proton, broad-line nuclear magnetic resonance spectrometry to estimate the organic carbon contents and the potential oil yields of five domestic oil shales. The quantity of organic hydrogen in the oil shales is mathematically related to the organic carbon contents and to the potential oil yields so that the proton, broad-line nuclear magnetic resonance signal strength can be correlated with both the fischer assay oil yield and the organic carbon contents of oil shales from Colorado, Utah, Wyoming, and Kentucky. The experimental data indicate that calibration curves need be determined but once for a limited oil shale area under development. The method is rapid, can be applied without extensive calibration, and gives good estimates of oil yields and organic carbon contents on as many as 30 samples per hour. Work done in cooperation with the University of Wyoming.