The Missouri Resource Assessment Partnership (MoRAP), a cooperative of natural resource agencies, mapped land cover for Missouri using satellite data. We initially derived land cover data for verification using an unsupervised, scene-by-scene classification. Then we developed a field sampling scheme based on spatial segmentation of individual TM scenes by ecological subsection that was designed to derive the maximum relevant information possible. Result shows field data quality varied due to the diversity of individuals involved, but the spatially segmented sampling scheme, large data volume, and final expert review ensured that the biases of any individual had negligible impact on the final land cover product. In order to efficiently process the large volume of incoming data, we developed the Missouri Land Cover Ground Verification Tool--a Microsoft Visual Basic application with data management, analysis, and mapping functions that bridges Microsoft Access and Esri's ArcInfo software.