My mother posted a little Utah travelogue, so I thought I'd share with you my more detailed tale of trilobite hunting, based on an email I sent to Jim, a co-worker of Sumana's to whom I gave a trilobite and a chunk of fossilized lakebed containing many trilobites:
The company that owns the trilobite quarry is U-Dig Fossils. They have no web site but there is a fan site which is probably better than their
actual web site would be.
The quarry is about 50 miles from Delta in central-west Utah. The whole
area used to be a lake and it looks like the quarry is sort of near the
north shore of the ancient lake; it's in the foothills of some small
To get to the quarry you go about 30 miles down highway 6 from Delta
(Delta itself is about 100 miles from Provo), then turn onto a dirt/gravel
road. The road goes north about 20 miles with some twists and turns. On the way there and back we
saw some deer and some penned-up cows.
The actual approach into the quarry is pretty scary; it's a very steep
downhill slope. We made it fine in my mother's SUV, and people on the
website talk about making it in their rental cars.
We were the only customers at the quarry. The guy in charge was working
down in the quarry under a tent. He came up to the office (a shack),
showed us some samples, gave us buckets and hammers, and made us sign
waivers. My mother brought an old geologist's hammer but the ones they
gave us were better. He then took us to a hill on the east side of the
quarry, above where another man was working under another tent, showed us
how to find the "bugs", and left us to dig.
The modus operandi of the quarry seems to be to dig up a bunch of small
rocks with a backhoe and leave them in huge piles.
You then climb on a pile, pick out a likely rock, and split it open. Try
to get as many slabs out of your rock as possible; every time you split a slab you have a new chance of finding trilobites. The quarry employees reserve especially rich trilobite veins for
themselves; they have a sideline selling trilobites to rock shops (actually, their sideline is probably letting people come to the quarry and dig).
The trilobite vein was very rich; I found some sort of fossil in perhaps half of the rocks I cracked. A lot of the fossils were the tiny Peronopsis interstricta which I eventually started
ignoring because they're not as cool.
Unfortunately, in my inexperience I ruined several
trilobites and caused several others to become disloged from their stony homes. There are a lot of trilobites, so the loss to science is not great. When a trilobite is knocked out of its matrix, it skitters away into the pile of rock chips at your feet and becomes less valuable, like a comic book taken out of its wrapping. Sometimes I was able to recover the fleeing trilobite; other times I was left with only its impression in the rock. If you pick through the fragments you can find loose trilobites lost by others; my mother and sister started doing this when they got tired of wielding the hammer.
The literature says to wear safety glasses but I found it was too hot, and the flying rock chips weren't getting anywhere near my eyes, so I got rid
of them after I filled my first bucket. I wore garden gloves the whole
time; that is definitely a good idea. I was wearing shorts but came to
regret it. It's pretty hot, but it's more useful to wear pants so that you
can kneel and lie down on the rock without getting scraped up. Also, bring
lots of water--I went through two big squeeze bottles in 2 hours.
We brought back 7 bags of trilobites. I had the
most because I worked longer, by my mother's looked the best as she has
more experience collecting rock samples. Total cost for 3 people: $36.
After the dig we were dirty and exhausted. We are not cut out to be
full-time trilobite diggers. We went back to Delta and crashed at the Best
Last night I cleaned the trilobites with my nonexistent trilobite cleaning
tools. I used a hammer and screwdriver to chip away some excess rock where
I could (I ruined the screwdriver; good thing it was just a dot-com
giveaway), and wiped off some dirt with water and cloth. One trilobite
negative dissolved when I tried to wash it; I wasn't expecting this and
felt bad about it.
I probably have a total of 20-25 non-Peronopsis trilobites, mostly
Elrathia kingi. 15 of them are loose or in their own rock matrices, and the
rest of them are hiding in two big chunks of fossilized lakebed.
The trip was a lot of fun. I definitely recommend it if you want to go
fossil hunting or have a day to spare on a Utah or cross-country vacation. If you were going from San Francisco through Salt Lake City on the 80 it would be a doable 1-day detour.