The work reported herein was done by the Bureau of Mines Petroleum and Oil-Shale Experiment Station at Laramie, Wyoming in cooperation with the University of Wyoming to obtain information that might lead to a more complete utilization of Wyoming asphalt-bearing crude oils. It involved the laboratory preparation of asphalts from Wyoming and other asphalt bearing crude oils , as determination of the yields, compositions and properties of the asphalts. The characteristics of various Wyoming crude oils, as determined by the Bureau of Mines method of analysis provide information on the naphtha and the oil fractions of the crude oils but do not give the yield and characteristics of their asphaltic portions. The present paper combines the results of previous investigations with recent studies on 117 asphalts form 25 crude oils of Wyoming, Arkansas, California, Montana and Mexico.