Fossil Fishing in Southwestern Wyoming Go fishing for fossils in the 52-million-year-old Fossil Butte Member of the Green River Formation with curator Dr. Lance Grande and his team. You won't have to worry about going home without a bite as the team expects to uncover several hundred specimens from the world's most productive freshwater lagerstätte (an unusually rich fossil deposit). Over the past 20 years, Dr. Grande has collected thousands of fossils, including plants, insects, mammals, crocodiles, birds, lizards, turtles, and, of course, fishes. Thanks to his efforts, The Field Museum currently boasts the world's largest and most extensive fossil collection from the Green River Formation. The Green River Formation Still Swimming, Walking, and Flying 50 Million Years Later The Art of Field Collection Bringing the Fossils to Life Special Thanks See images of Dr. Grande and his team from a recent trip into the field in the Vertebrate Paleontological Fieldwork 2004 website.