This CD-ROM contains files in support of the 1995 USGS National assessment of United States oil and gas resources (DDS-30), which was published separately and summarizes the results of a 3-year study of the oil and gas resources of the onshore and state waters of the United States. The study describes about 560 oil and gas plays in the United States; confirmed and hypothetical, conventional and unconventional. A parallel study of the Federal offshore is being conducted by the U.S. Minerals Management Service. This CD-ROM contains files in multiple formats, so that almost any computer user can import them into word processors and spreadsheets. The tabular data include some tables not released in DDS-30. No proprietary data are released on this CD-ROM, but some tables of summary statistics from the proprietary files are provided. The complete text of DDS-30 is also available, as well as many figures. Also included are some of the programs used in the assessment, in source code and with supporting documentation. A companion CD-ROM (DDS-35) includes the map data and the same text data, but none of the tabular data or assessment programs.