The 17 Western States plus Arkansas, Florida, and Louisiana account for 94 percent of all U.S. irrigated acreage, with the Western States alone contributing over 85 percent. This report integrates data on the distribution, characteristics, uses, and management of water resources from a wide variety of data sources. The report includes charts and tables on the climatic and physiographic influence on irrigation development; farm data comparing selected characteristics of irrigated and nonirrigated farms; and data on water application systems, sources of water, pump energy expenses by energy type, values of irrigated and nonirrigated land, and cash rents.