This GIS shapefile, "density_contours," describes 1) a bison study area at Tallgrass Prairie National Preserve, Kansas, and 2) 25%, 50%, 75%, and 99% kernel density contours for locations of bison marked with GPS collars during 2021-2023. Percentages associated with contours describe nominal coverage, i.e., proportions of observations they are expected to encompass, and approximate the distribution of bison activity within the study area. Each contour encompasses lower-coverage contours: the 75% contour, for example, encompasses the 50% and 25% contours but not the 99% contour. An accompanying child item, "quantile_bands," is a GIS shapefile that describes quantile bands corresponding with intervals between contours in "density_contours." Each of the first 4 bands encompasses approximately 25% of bison locations. Percentages associated with contours describe nominal coverage, i.e., quantiles the bands are expected to encompass. Bands comprise a partition of the bison study area and do not overlap. Users are advised that ground conditions within the study area may change over time, leading to changes in bison distribution.