This dataset identifies the amount of wet, dry, and total deposition of nitrogen in kilograms per hectare from 1989 to 1991 at a set of point locations across the contiguous 48 states. Summary data in this indicator were provided by EPA’s Office of Atmospheric Programs, based on deposition data from two sources. Wet deposition data are from the National Atmospheric Deposition Program/National Trends Network (NADP, 2018) (http://nadp.slh.wisc.edu/), and dry deposition data are from the Clean Air Status and Trends Network (U.S. EPA, 2018) (https://www.epa.gov/castnet). This indicator aggregates data across 3-year periods to avoid influences from short-term fluctuations in meteorological conditions.