Frank Royse, influential structural geologist for Chevron, specialized in Foreland Basin Thrust Belt exploration. He was instrumental in the development of the Wyoming and Utah Thrust Belt in the Fossil Basin, finding several oil and gas fields on the hanging wall of the Absaroka Thrust Fault. Frank’s team discovered the Ryckman Creek, Painter Reservoir, and East Painter Reservoir fields, all producing from the Triassic Nugget sandstone, and the Whitney Canyon and Carter Creek fields producing principally from Mississippian Mission Canyon carbonates. Source rocks for oil and gas trapped in these fields are from the Cretaceous Hilliard shales in the footwall of the Absaroka Thrust Fault. Chevron, partnered with Amoco, found reserves of over 700MMBO and more than 9TCFG. Their exploration success in this foldbelt served as an influential analog throughout the world’s foldbelts.