These data represent occupancy estimates for western bumble bee across the western continental United States and the spatial variation in detection probabilities that occur during bumble bee surveys. This product contains five raster layers (appearing as separate bands in a multi-band raster). The first two bands represent the predicted occupancy of western bumble bee in 1998 and 2018. We modeled western bumble bee occupancy as a function of: latitude, longitude, elevation, year, and land cover. The last three bands represent the spatial variation in detection probabilities predicted to occur for surveys conducted across the western United States on three dates (May 15, July 15, and September 15). We modeled detection probabilities as a function of: land cover, bloom date (the date at which floral resources become available), days since bloom initiation, and the interaction between bloom date and days since bloom. Further details on the creation of this product are described in: Graves, T.A., Janousek, W.M., Gaulke, S.M., Nicholas, A.C., Keinath, D.A., Bell, C.M., Cannings, S., Hatfield, R.G., Heron, J.M., Koch, J.B., Loffland, H.L., Richardson, L.L., Rohde, A.T., Rykken, J., Strange, J.P., Tronstad, L.M., and C.S. Sheffield. 2020. Western bumble bee: declines in the continental United States and range-wide information gaps. Ecosphere, 11(6), p.e03141. https://doi.org/10.1002/ecs2.3141 This supports pre-listing science for species under consideration by the U.S. Fish and Wildlife Service.