The United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS) recently revised its ground-penetrating radar (GPR) soil suitability maps (GPRSSM). These maps, which have been prepared for most areas of the USA at different scales and levels of resolution, show the relative suitability of soils for GPR soil investigations. These digital maps are based on physical and chemical properties of approximately 22,000 different soils. The smaller scale (1:250,000) Ground-Penetrating Radar Soil Suitability Map of the Conterminous United States shows the relative suitability of soils to GPR within major soil and physiographic areas. The larger scale (1:12,000 to 1:63,360) state ground-penetrating radar soil suitability maps duplicate the scale and level of detail of the original soil survey maps. GPR soil suitability maps have been used to evaluate the relative appropriateness of using GPR, select the most suitable antennas, and assess the need and level of data processing. Limitations of these maps are discussed and examples of radar records collected in soils having different GPR suitability indices are presented.