Phareodus sp. fish and piece of fossilised wood, USA (Wyoming, Green River formation), Eocene, (50 million years old), on custom-made base, 24 x 58 cm

The Green River in Utah, Colorado and Wyoming is famous for its vast oil shale deposits and wonderfully preserved fossils. Fossil Butte National Monument in southwestern Wyoming preserves and displays some of these high quality fossils. Leaves and fish are the most common large fossils in the Fossil Lake basin of the Green River.