This dataset includes information for 200 pesticides on the average amount (pounds) applied to 87 agricultural crops and the acres of crops treated for counties within the conterminous United States. These data were derived by combining published state pesticide use coefficients published by the National Center for Food and Agricultural Policy (NCFAP) and county harvested crop acres available from the 1992 Census of Agriculture. A description of the methods used to develop the county database is published in USGS OFR 00-250, "Method for Estimating Pesticide Use" and is available online from: http://pubs.er.usgs.gov/pubs/ofr/ofr00250. Maps showing the geographic distribution of use patterns for 199 compounds (BT was not mapped) area available from http://ca.water.usgs.gov/pnsp/. The pesticide use estimates contained in this file represent average usage patterns for the years 1990-1993 and do not represent a specific year. The key limitations of the data include the following: (1) state use coefficients represent an average for the entire state and consequently do not reflect the local variability of pesticide management practices found within states and counties, (2) pesticide use estimates are not for a specific year, but represent typical use patterns for a four year period, (3) state pesticide use coefficients many not have been available for all states where a pesticide may have been applied to agricultural land, and therefore, are not included, and (4) the county crop acreage use to estimate county pesticide use is from the 1992 Census of Agriculture and may not represent all crop acreage because of Census nondisclosure rules.