Bob Weimer is a petroleum geologist who had initial success as an explorationist, and later as a professor. Recognizing the significance of Cretaceous shoreline sandstones pinching out across the Wamsutter Arch in southern Wyoming, Bob discovered the Patrick Draw Field (Arch Unit). He subsequently discovered the nearby Desert Springs Field. Both fields were significant new plays in the late 1950s in the search for stratigraphic traps in the Cretaceous strata of the Western Interior. Later, Bob discovered the Spearhead Ranch and Powell (Manning Ranch) fields in the Powder River Basin. He spent most of his career as a professor at the Colorado School of Mines, where he taught stratigraphy and field geology to hundreds of students. Bob has published many significant papers on different Rocky Mountain reservoirs, which are considered important analogs to the reservoirs around the world. He served as AAPG President, and is a Sidney Powers Memorial Award recipient. The SEPM honored Bob with its William H. Twenhofel Medal. He is also a member of the National Academy of Engineering.