Sediment thickness is a crucial measure for many seismic studies. The slow velocities associated with thick sedimentary sequences can be problematic when inverting for tomographic images of the crust and upper mantle structure, and is an essential piece of information for better constraining ground motion models as sediments are known to amplify shaking. Yet there is currently no self-consistent map of sediment thickness across the conterminous United States that can be used for these purposes. In this work we measure the delay time of P to S conversions at the sediment-basement interface from a set of teleseismic receiver functions, and demonstrate the geographical correlation with known sedimentary provinces. From this we produce two maps of sediment thickness, (i) using a borehole derived empirical relation and (ii) a tomographic velocity model. While the former is likely an underestimate, the latter is an excellent first-order representation of sediment thickness across the continent.