Our bucket list camping trip in the summer of 2022 will long be remembered as perhaps our best ever. Yellowstone National Park has that affect on memories. And while Yellowstone was the certainly the centrepiece of the trip, our four hours hunting Green River Formation fossils at American Fossil Quarry were, without question, the highlight.
I have a love/hate relationship with fossils. On one hand, they’re freaking awesome. On the other hand, they’re hard to get where I’m from. And by that, I mean, the cool ones are difficult to obtain … by myself … legally.
Incredible fossils can be found in great abundance not too far from my home. A couple hours of driving and a hike would have me plundering the famed Burgess Shale in the Canadian Rockies. Sounds like a great way to spend the day. Until I’m arrested, anyway.
Collecting fossils from this geological heritage site is wholly outlawed, as it is in all national parks. And rightly so, because were it not, folks like me would have picked that quarry clean decades ago.
Rules for collection of fossils vary by jurisdiction. Here in Alberta, surface collection is allowed but ownership remains with the crown. You’ll need their permission to do anything with it beyond setting it on a bookshelf in your home. And, honestly, finding noteworthy fossils just lying on the ground is a rare feat.
That’s assuming you can get to a spot likely to have such fossils lying around. Often the best collection sites have been incorporated into a park or similar protective entity and are almost always off-limits to hunting. Private land requires owner permission, which isn’t always forthcoming. Crown land is plentiful, but you’ll need patience or not-so-public knowledge to even find a hotspot.
All of which is to say that driving to a public quarry, paying some money, and filling your trunk with incredible fossils in a couple of hours doesn’t happen here often. Or ever.
Thankfully (I think … my moral compass spins uncontrollably on this matter), several states in the USA do not enforce any such limitations. Therefore, when planning our camping trip of a lifetime, I eagerly tacked on a few hundred extra miles of driving to do a little legal plundering in the legendary Green River Shales of Wyoming, Colorado, and Utah.
These shales, officially known as named the Green River Formation, were deposited in three intermontane lakes during the Eocene, some fifty million years ago. Though not exclusively shales, the formation is renowned for its very finely layered varves that demark seasonal deposition over a continuous six-million-year period.
The larger deposits in Utah and Colorado represent the biggest oil shale deposits in the world, with an estimate three trillion barrels in place. It’s the runt of the litter in southern Wyoming, however, where things get interesting.
There, in two distinct layers (split fish layer, 18-inch layer), an unbelievable bounty of fossils is preserved, often with spectacular detail, in the lime muds of the Green River Formation. Fish are the most common fossil (stingrays being the holy grail), but insects, plants, reptiles (crocodiles), and mammals (bats) can also be found. With a few greenbacks and some sweat equity, you can bring home a hoard of your very own.
To hunt for Green River Shale fossils, you’ll need to make your way to (or near) Kemmerer, Wyoming. That’s a solid four-hour drive from the southern entrance to Yellowstone, putting you kind of in the middle of nowhere. If it weren’t for the fossils, I can’t imagine any reason to visit this city of 2650.
Currently, there are seven quarries (don’t hold me to that number) offering fee dig services in the rugged, dry ranch lands west of Kemmerer. Each has its own set of hours, fees, and rules on what you can keep, typically based on the quality of fossil-bearing rock within their quarry. Prepare for some sticker shock if you want the most exclusive finds possible.
I spent a couple weeks debating which operation to use, finally settling on American Fossil Quarry due to their reasonable cost and seemingly generous policy of letting visitors keep everything they find valued below $100,000. I had little interest in traveling that far only to have the bulk of my discoveries confiscated due to their rarity. Hey, it’s good to be optimistic!
Having decided on a quarry and having one specific day available in our itinerary, I didn’t want to show up and not be able to dig, so I booked our spot online rather than commit to a walk-in. Walk-ins are welcome here and at some of the other quarries as well, so you can do that if you’re a more relaxed traveler than I.
I chose the four-hour dig, hoping to arrive for an 8:00 start. This would give us four hours of fossil hunting before the worst of the midday sun bore down on the quarry. In early July, the temperatures were easily pushing into the early thirties (Celsius) and I am not a sun worshipper.
We were hauling a trailer and appealing campgrounds are all but non-existent in the Kemmerer area. Instead, we set up shop at Bear Lake State Park in northeaster Utah. As a result, we had an hour’s drive from campsite to quarry. Well, that’s how long it should have taken.
American Fossil’s website very clearly warns that Google Maps does not direct you to the quarry correctly if travelling from the west. I saw this warning when I booked and made a mental note of it for when we were finally driving to the quarry.
Unfortunately, being fifty, my mental note had the staying power of Hugh Hefner without Viagra and I promptly followed Google’s directions straight into a nightmare of unimproved ranch roads with ruts worthy of their own national park status.
Thanks to a friendly park ranger (they must be used to ding dongs like me), our error was corrected (my mental note magically reappeared precisely at that moment) and we finally arrived at American Fossil Quarry. Late. Frazzled. But ready to get to work.
For the record, you need to go into the city of Kemmerer and then head north before snaking westward into the hills. For your sake, and your marriage’s, use the website instructions!
The proper route to the quarry was much better driving, though the last few miles are nonetheless rough. You’ll be happier navigating the gravel ranch roads in something more robust than a sedan. Slow and steady will win this race. And keep an eye out for cows.
As you near the quarry, you’ll pass a small gathering of travel trailers surrounding a small building. This isn’t a campground and I suspect it might be where seasonal staff at the quarry set up their mobile homesteads. These fee dig businesses do not run year round, and the drive back to town could get a little tedious every day. Can’t say the lack of shelter appeals to me, but it would otherwise be a heavenly way to spend a summer as a young man or woman.
Once on the premises, there’s no mistaking this is a quarry. It’s a public access attraction, but nonetheless a place of physical labour involving chunks of earth. There is no asphalt, blinking lights, or fancy visitor centers out here. Just rock, dust, shacks, and machinery. You grunted like Tim Allen, didn’t you?
As such, you’ll want appropriate clothing. Sun dresses and flip flops won’t be suitable no matter how weather appropriate. Work gloves and sturdy footwear are a must. Steel-toed boots aren’t a requirement, but you wouldn’t be snickered at for wearing them. Our hiking boots did the trick, with light, long sleeve shirts and full pants rounding out the wardrobe. Sunglasses and hats are also recommended, with a full brim superior to ballcaps. Can you tell I loathe the sun?
Parking is found in an open space well back of the main quarrying area. If you’re visiting in summer, your car is going to roast out in the sun, so don’t be leaving water bottles sitting around inside. With the dust, you won’t be keen to leave the windows rolled down and the water will be bath warm by the time you need a drink.
And you will need a drink. Plenty of them. It gets unforgivingly hot with that sun blazing down on you for hours on end. As you can see in the photos, there’s hardly a tree or cloud to be found. Bring lots of water, snacks, and sunscreen. And be sure to drink the water. The excitement of finding fossils can easily distract you from your progressing dehydration.
The first stop is the main office, a newer, portable building (doghouse in geo-lingo) that doubles as a gift shop. Inside are some folding tables behind which the friendly staff get you signed in and ready for fossil hunting.
A small assortment of beverages is available for purchase, so if you do forget to bring our own you won’t become a buzzard’s lunch. But bring your own. You’ll need lots.
The gift shop is modest and there are some fossils available to purchase. Some of the quarries have larger, stand alone fossil shops, either in Kemmerer or on the main roads to the city, where premium samples can be bought. And if you’re curious for a more in depth learning experience about the Green River Formation and it’s amazing fossils, the Fossil Butte National Monument with its modern visitor center full of interesting exhibits is a fifteen minute drive west of Kemmerer.
American Fossil Quarry also has a museum on-site, albeit a small one. It’s in an older, rather rough shack next to the main office. Posted on the bare walls inside are some information placards discussing the quarry history and the Green River Shale fossil beds. It’s worth a couple minutes of time to snoop around but not much more.
As mentioned, I booked a four hour fossil dig for our family of four (2 adults and 2 kids). In 2022, that cost us $334 US. There are shorter and longer options available, including full day digs if you’re ambitious. You can even book a private dig for groups or serious collectors.
After check-in, another member of the staff gathered us out front of the office for a summary of the quarry rules and a short presentation of what we are likely to find. It’s helpful, don’t get me wrong, but by this time you’re chomping at the bit to get busy finding fossils and can’t wait for the talking to stop.
After that, your designated guide will take you to the large, roped-off area with orange pylons denoting the fossil dig space for paying customers. Everyone is given a rock hammer and blade chisel, though you can bring your own if you have them (we brought our own rock hammers because we’re nerdy geoscientists).
The guide gives a quick demonstration on how to split the rock using the hammer and chisel and then it’s a free for all. Long piles of fossil bearing rock lie in rows within the hunting space, the outcropping Green River Formation as backdrop. You can hammer away at any rock as you see fit, so long as it is inside the roped area. Keep to yourself or mingle with others. Chat with guides, or put your head down and work, work, work.
The rock within the designated dig area is all taken form the thicker, prolific split fish layer. The first thing you’ll notice is that it truly is prolific. Mind-bogglingly so. You’ll find at least a partial fossil within the first couple of rocks you split. With that, you’ll be hooked. Even the least interested in rocks member of your entourage will be eagerly hammering away hoping to find the next cool fossil.
At the end of each row of rocks is a steel shelving unit and a wheelbarrow. Each group of guests claims one of these and it is used for stowing your finds and eventually transporting them to your vehicle at the end of your shift.
It might seem ridiculous having an entire shelving unit for stacking fossils, but you really will find that many. Honest. It’s truly remarkable.
Depending on your personal tastes, not to mention upcoming travel requirements, the number of fossils you end up keeping will vary. We had another week of camping ahead of us, not to mention a drive back to Canada. We needed to high-grade our finds, only keeping the best of the best yet we still ended up with a few boxes full of fossils plus a couple large slabs!
American Fossil Quarry aims to maximize the fossil haul and thus they have rules on how big the rocks can be when you take them. For instance, they want you to slab the rock to less than 2” in thickness. This makes sense as there can be multiple fossils in different layers of a rock chunk. Split too finely and the fossils can break. Keep them too thick and you’re potentially escaping with unknown treasures. For us, having so much driving to do, the thinner the better.
Form a width perspective, blank rock is pointless to take home. Sometimes you find a small fish in the corner of a larger rock slab, most of which can be discarded. Quarry staff are always quick to help and can bring a powered concrete saw to cut away unneeded sections of large, heavy rocks.
If your sample could use trimming but isn’t large enough to warrant on-the-spot cutting, a selection of concrete chop saws is setup on tables near the office. Customers can cut away their own waste rock, leaving your fossils in manageable sizes. A massive pile of discarded rock shards grows on the backside of the cutting area. I can only imagine what preserved treasures have been inadvertently lost in there.
The most heart-breaking part of this entire experience is the finding of a partial fossil. Fish are by far the most common fossil at American Fossil Quarry, and often times you’ll find a tail missing or fin sliced off. The source rock is taken directly from the fractured cliff face with a bobcat and/or front end loader. This isn’t delicate, precise work. Inevitably, a fossil will be broken in half just in retrieving it from the outcrop.
Furthermore, you’re splitting the rock with a hammer and chisel. The staff teaches you the most effective way to split the layers but again, the nature of rock can be unpredictable. Pieces will break and ruin fossils in doing so. It’s disappointing, sure, but with persistence you’ll eventually be rewarded with many excellent, full fossils to take home.
The staff at American Fossil Quarry were fantastic. Our primary guide was a deeply tanned, bearded fellow named Justin. He was incredibly helpful, but more importantly, he was as enthusiastic about our finds as we were. The way he went on about each fossil we exposed, I was sure he must be a geology student, maybe even a paleontologist. Nope. Just a guy who finds fossils amazing spending a summer in what I can only imagine is a brutal, exhausting dream job.
Justin and the other guides were invaluable in teaching us about our finds, namely giving our fossils … umm … names. Sometimes it was a simple as saying “that’s a crocodile tooth”. Other times it was more scientifically technical using the appropriate genus such as Knightia. This added knowledge really upped the experience level for me.
Then Justin did something that truly put our adventure at American Fossil Quarry over the top. As our third hour approached its end, Justin asked me if I was interested in hunting through some harder rock. Outside the designated hunting area was another collection of rocks. These were much larger than the ones we’d been splitting and were much harder, coming from the 18” zone of the Green River Formation.
This zone, though thinner and less prolific, is prized for its larger fossils. You won’t find nearly as many fossils, but the ones you do find, say a fish, can be much larger. Sign me the up!
Except, there’s a catch. This harder rock requires larger hammers and proper fist-grip chisels to split and thus is restricted to patrons 18 years of age or older. That’s a benchmark I passed decades ago, but my fossil-loving son was only 13. Talk about a parenting conundrum!
I discussed it with my family, my son in particular, and we agreed that the lure of larger fossils trumped the disappointment of him not being able to assist in the hunt. So I left my family to continue in with the split fish rocks while I went mammoth hunting in the 18” rocks.
These rocks were indeed harder and less prolific. I’d been working for three hours already and now I was swinging a heavier hammer with far more force onto a chisel struggling to impale less forgiving, not to mention more massive, rocks. I thought about quitting but persisted and was eventually rewarded with two large fish specimens that not only wowed my boy but impressed Justin as well.
One was a Phareodus that, though cool, was positioned right on the edge of the rock and is thus missing its tail. The other one … well … it made all that heavy hammering worthwhile.
It’s a Priscacara (Priscacara serratta to be more specific, I believe) overlying a crawdad (crayfish where I come from). I was informed that Priscacara had teeth in the side of their mouths that enabled them to crush and eat crustaceans. Perhaps my fossil is an attempted meal gone wrong. Damn cool fossil regardless.
In this situation, the quarry staff are willing to ignore the rock thickness rules rather than risk ruining impressive fossils by trying to further split this harder rock. They used their portable concrete saw to trim the areal size of my finds, but the Priscacara chunk remains five inches in thickness. I’m sure that added a couple bucks to our gasoline bill on the return home.
It’s now six months later and we still reminisce about how awesome our time at American Fossil Quarry was. I still look at our fossils and marvel at the number of them we found. No stingrays, unfortunately, and nothing that would have tested the $100,000 limit for keeping, but they’re still damn cool fossils.
On our drive home, my son was fantasizing about working at the quarry. Okay, he actually wants to own one, but I’m guessing the price tag is a bit out of reach. But working at one of these quarries for a summer would be fantastic. The staff are allowed to fossil hunt after work hours which is a phenomenal perk. I can’t stand sun or heat, and I’d sign up for a tour of duty with nary a hesitation.
I would happily go back to American Fossil Quarry. I’m convinced I will one day. In fact, I’d love nothing more than to try out all the different quarries and see what we find in the different environments preserved in each. But if you’re looking for one to start with, I have no hesitation in recommending American Fossil Quarry.
I only wish it was closer to home.