National maps of precipitation intensity (TP-40, and NOAA Atlas 2, for example) are 30-40 years old, and quite outdated. The National Weather Service’s Hydrological Design Studies Center has recently teamed with Oregon State University’s Spatial Climate Analysis Service to use the PRISM modeling system to update these maps. In the initial effort, precipitation frequency maps will be updated for the Semi-Arid Southwest and Ohio River Basin. Anticipated follow-on work will encompass the remainder of the United States, including Alaska, Hawaii, Puerto Rico, and Virgin Islands. One of the major predictive elements for these maps will be high-quality, peer-reviewed PRISM grids of 1961-90 mean annual precipitation, supported by the USDA Natural Resources Conservation Service.