TY - RPRT TI - Exploration intensity map of the Upper Cretaceous D Sandstone, Denver basin, Colorado, Nebraska, and Wyoming AU - Debra K. Higley AU - D. L. Gautier AU - Richard F. Mast PY - 1987 DO - 10.3133/ofr87351a UR - https://pubs.usgs.gov/publication/ofr87351A ID - ofr87351A ER -