Livestock is considered to be the second largest source of anthropogenic methane emissions in the United States. Top-down approaches for methane source attribution have questioned existing bottom-up estimates of methane emissions, such as the U.E. Environment Protection Agency’s (USEPA) Inventory of Greenhouse Gas Emissions and Sinks, suggesting that livestock emissions are underestimated. This analysis used a spatially-explicit, bottom-up approach, based on animal inventories, feed dry matter intake, and dry matter intake-based emission factors to estimate county-level enteric (cattle) and manure (cattle, swine, and poultry) methane emissions for the contiguous United States. Counties with the largest combined livestock methane emissions included: Tulare, Merced, Stanislaus, and Kings, CA (217, 123, 80, and 78 Gg methane/year, respectively); Gooding, ID (75 Gg/year); Weld, CO (63 Gg/year); Kern, Fresno, and San Joaquin, CA (62, 59, and 49 Gg/year), Maricopa, AZ (47 Gg/year), and Sampson, NC, Yakima, WA, and Sioux, IA (43 to 44 Gg/year). Overall, the bottom-up approach used in this analysis yielded total livestock methane emissions (8,888 Gg/yr) that are comparable to current USEPA estimates (9,117 Gg/yr) and to estimates from the global gridded Emission Database for Global Atmospheric Research (EDGAR) inventory (8,657 Gg/yr), used previously in several top-down studies. However, the spatial distribution of emissions developed in this analysis differed significantly from that of EDGAR. As an example, methane emissions from livestock in Texas and California (highest contributors to the national total) in this study were 36% lower and 100% higher, respectively, than estimates by EDGAR. The difference for these 2 states between the current analysis and the latest USEPA gridded inventory was 15 and 4%, respectively. The spatial distribution of emissions in gridded inventories (e.g., EDGAR) likely strongly impacts the conclusions of top-down approaches that use them, especially in the source attribution of resulting (posterior) emissions, and hence conclusions from such studies should be interpreted with caution.