Land supply elasticities determine the rates of land conversion in global policy models. However, they are only available for few countries in the world. Therefore, analysts seeking to improve the spatial resolution of their models are forced to impose regionally homogeneous parameters over highly heterogeneous regions. This article estimates spatially explicit land supply elasticities using gridded data for the American continent. These esti- mates reasonably reproduce changes in land use observed at different levels of geographical aggregation across the continent. Plugging our estimates in a previous analysis of the land-use effects of eliminating global un- sustainable irrigation, reveals higher pressure to convert land in the ecoregions in the south of the continent that have experienced most rapid cropland expansion in the recent past.