Artificial drainage, whether surface or subsurface, profoundly affects the productivity of soils and the hydrology of watersheds. Modern production agriculture would not be possible without the extensive drainage network that has been built up starting in about the 1850's. While an unqualified success for increasing agricultural production, research over the past quarter century has illustrated the important role drainage plays in determining the quality of surface water where drainage is used. Because of its distributed nature, extended installation history, the invisibility of subsurface drains, and the lack of a systematic survey in recent years, the extent of drainage in the US is poorly known. In this study, we used the information contained in the NRCS STATSGO soils database in conjunction with the National Land Cover Dataset for 1992 compiled by the USGS to estimate the distribution and extent of drainage across the U.S. Various soil characteristics within the database such as drainage class, hydrologic class, and land capability class are compared to existing surveys and NRI data for determining the distribution of drainage. Results are summarized in a series of maps and tables giving percentage of drainage at both the state and county level.