In 2000, NETL conducted a review of the adequacy of the resource characterization databases used in its Gas Systems Analysis Model (GSAM). This review indicated that the most striking deficiency in GSAM?s databases was the poor representation of the vast resource believed to exist in low-permeability sandstone accumulations in western U.S. basins. The model's databases, which are built primarily around the United States Geological Survey (USGS) 1995 National Assessment (for undiscovered resources), reflected an estimate of the original-gas-inplace (OGIP) only in accumulations designated ?technically-recoverable? by the USGS ? roughly 3% to 4% of the total estimated OGIP of the region. As these vast remaining resources are a prime target of NETL programs, NETL immediately launched an effort to upgrade its resource characterizations.