Two different great basin perimeter files were intersected and dissolved using ArcGIS 10.2.2 to create the outer perimeter of the great basin for use modeling long-term wildfire effects on sage-grouse population growth, and development of sage-grouse concentration areas based on modeled habitat quality, lek density, and population abundance (Coates et al. 2015). These two perimeter files included a 1:1,000,000 map of hydrographic areas in the Great Basin) (Buto 2009), and vegetation characteristics (Karl et al. 2001). The resulting Modified Great Basin Extent represented a combination of hydrographic and floristic features best suited for the defining the spatial extent of the analyses. To ensure moving window analyses of habitat and fire areas covered the entire extent, the extent was then buffered by 15.8 km. The extent also encompasses large parts of sage-grouse management zones III (Southern Great Basin), IV (Snake River Plain), and V (Northern Great Basin). A small portion (< 5%) of management zone II (Wyoming Basins) is also encompassed. REFERENCES Buto, S.G., 2009, Digital Representation of 1:1,000,000-scale Hydrographic Areas of the Great Basin: U.S. Geological Survey Data Series 457, 5 p .http://pubs.usgs.gov/ds/457 Coates, P.S., Ricca, M.A., Prochazka, B.G., Doherty, K. D., Brooks, M.L., Casazza, M.L. 2015. Long-term effects of wildfire on greater sage-grouse - integrating population and ecosystem concepts for management in Great Basin. http://pubs.er.usgs.gov/publication/ofr20151165 Karl, M., Durtsche, B.M., Morgan, K. 2001. Great Basin Restoration Initiative Area. http://sagemap.wr.usgs.gov/SearchData.aspx