Downloads and additional Metadata. A tiled map service depicting wildland urban interface data for 1990. The wildland-urban interface (WUI) is the area where houses meet or intermingle with undeveloped wildland vegetation. This makes the WUI a focal area for human-environment conflicts such as wildland fires, habitat fragmentation, invasive species, and biodiversity decline. Using geographic information systems (GIS), we integrated U.S. Census and USGS National Land Cover Data, to map the Federal Register definition of WUI (Federal Register 66:751, 2001) for the conterminous United States for 1990. These data are useful within a GIS for mapping and analysis at national, state, and local levels. Data are available as a feature class and include information such as housing and population densities for 1990; wildland vegetation percentages for 1991; as well as WUI class in 1990. This WUI feature class is separate from the WUI datasets maintained by individual forest units, and it is not the authoritative source data of WUI for forest units. This map service shows the WUI data for 1990 only.