Prior to this study, very little work had been done on the tight gas accumulation in the Wind River Basin. In fact, so little was known that although identified, it was not assessed in the 1995 National Assessment (Gautier and others, 1995). The Wind River Basin is sparsely drilled when compared to other Rocky Mountain basins such as the Piceance, San Juan and Greater Green River basins, making it difficult to define the limits of the basin-centered accumulation. This paper summarizes the extensive work recently completed on this tight gas accumulation. For the complete results of the study please see Johnson and others (1996a; 1996b,212 ); and Nuccio and others (1996). The objectives of our investigations are to characterize the geology of the tight gas resources of the Wind River Basin, Wyoming and to assess in-place resources. These in-place numbers are used by the U.S. Geological Survey and other assessment groups to estimate recoverable resources using various economic and technological assumptions. Estimating recoverable resources is greatly aided by the detailed geologic investigations summarized here and presented in more detail in the publications mentioned above.