- One fossil fish. The square measures 6 inches by 4 inches. The fish is very well preserved with many details visible. (See pictures)
- The fossil fish are preserved in very fine sediments that were deposited continuously for 6 million years. Each year two distinct layers were deposited, one during the growing season and the other during the dry season. The average thickness of these fine layers is about .2mm
- The fossil record indicates that this represented a sub-tropical to temporate region during the Eocene.
- There are about 25 known species of fish from the Green River Formation but many are extremely rare. Knightia, Diplomystus and Priscacara are the most common species. Phareodus and Mioplosus are uncommon and after that everything gets pretty rare.
- Besides fossil fish the Green River Formation also preserves exceptional plant material, insects and very rarely birds, mammals and crocodilians.
- Most fossil fish quarries are from two layers. The split fish layer where the fish typically split out on the surface of the bedding plane and the 18-inch layer where they typically are buried under the surface of the rock. The 18-inch layer produces better preservation but requires much more time and skill to collect and prepare.