A goal of the Air Force Research Laboratory Opportune Landing Site (OLS) program was to locate large, smooth, flat, obstruction-free areas safe for aircraft operations. The ERDC was tasked to evaluate the quality of OLSs as located by OLS Multi-Spectral (OLS-MS) software that was developed by the Boeing Company and uses Landsat multispectral imagery. ERDC conducted extensive field work evaluating OLSs in Indiana, New Mexico, and California. However, while seeking these OLS-MS-selected field sites, many other software-selected potential OLSs were casually observed not to satisfy requirements with regard to obstructions. Our objective was to evaluate a statistically valid sample of OLSs for freedom from obstructions. We utilized OLSs located by the final version of the OLS-MS software, plotted them over orthophotoquads, and assessed their intersections with obstructions within geographic information system (GIS) datasets containing natural and cultural features. A sample of OLSs was also visually evaluated to assess the accuracy of the GIS analysis process. Features in the GIS datasets often did not correspond exactly with features on the ground, a source of analysis error that may be due to digitizing uncertainty and differences in the creation dates of the images and datasets. The success of the OLS software in avoiding obstructions is presented in the results.