During the early Eocene Epoch, about 50 million years ago, sediments in large lakes in several western states created the Green River Formation. Southwest Wyoming has several pay-to-collect quarries where Green River Formation fish fossils are easy to find. A few weeks ago I went to the American Fossil quarry just outside of Kemmerer, Wyoming to dig for fish (and their website is fishdig.com). Besides fish, less common to rare fossils are there and include shrimp, insects, plants, crocodiles, birds, and bats. The matrix is an incredibly fine-grained siltstone and limestone that slowly breaks down into white dust that covers everything in the quarry. Some of the fish are well exposed when the matrix is split, but many pieces require work with magnification and a precision X-ACTO knife to expose the fish bones. Because the matrix is so soft, after the fish is exposed every piece has to be covered in polyvinyl acetate glue for strengthening. Kemmerer is also about 25 to 30 miles west of the famous Blue Forest petrified wood site (agatized wood). The Blue Forest is nearly impossible to find without a local collector to act as a guide, so I didn't make it there (maybe next year). First 2 photos show the quarry. Third photo: the hills and buttes all around the quarry must contain literally millions of fossils. First fish photo: pair of Knightia. Next: single Knightia. Next: Diplomystus. Next: Phareodus. Final: Another Diplomystus.

Very cool report and great pictures Victor.  Well done on those finds!!

Here is one more fish I just finished working on to reveal its bones (a Priscacara). Too bad its tail is missing.  Joe, I flew to Salt Lake City and then back home from there. Had to package up - with bubble wrap and plastic peanuts - and mail all pieces to my home address. This is a problem as the matrix is very soft and tends to break no matter how well cushioned the pieces are. If I go next year I may drive to avoid the problems of breakage.

Wow Victor!  Those are really cool fossils.  Sounds like a fun trip!