Fossil Butte National Monument, Hiking, National Parks & Monuments, State Parks, United States, Work Travel Life, Wyoming

Wyoming Hiked: Historic Quarry Trail at Fossil Butte National Monument

The Adventuring Heidi

Located in the absolute middle of nowhere between Kemmerer and Cokeville in southwestern Wyoming, Fossil Butte National Monument seems to be one of those places people poke around at on a journey to somewhere else, namely Wyoming’s two famous national parks, Grand Teton and Yellowstone. I am probably no different, as all my visits have been stopovers on travels through western Wyoming – a good place to use clean restrooms (that include amazing fossilized poop displays!), stretch the legs, browse a gift shop, and collect a few stamps in my national parks passport. Time to change that!

In the ridges of southwest Wyoming are some of the best-preserved fossils in the world. They tell the story of ancient life in a warm, wet environment in and around a freshwater lake. Stingrays swam in the lake. Turtles basked in the sun. Leaves rustled in the breeze while early horses darted between the trunks. 

National Park Service

With an hour to spare between thunderstorms to break up the drive from Cokeville to Evanston, I settled on hiking the Historic Quarry Trail, the longest trail of the monument’s four miles of maintained hiking trails. (Learn more about hiking at Fossil Butte National Monument here.). A loop of 2.5 miles (with a mighty 700 feet of elevation gain) takes you through the Green River and Wasatch Formations and up to a historic quarry area. Fossils are not readily viewable on this hike, but expansive views are… and I like myself a good view! And rocks… I like cool rocks 🙂

Obligatory trailhead signs at the start of the Historic Quarry Trail
Start of the loop. I opted for clockwise (the left spur).

I set out under cloudy skies and in the typical strong Wyoming winds, choosing to go clockwise so I could get the bulk of climbing out of the way in the first half of the hike. I hustled along, glancing at the educational signs as I came across them, and hoping the not-too-distant storms stayed away. Occasional benches dotted the trail, offering relief from the climb for those who desire.

An example of the education signs along the trail
Sheet of rain across the valley
Through the sea of sagebrush… which was the bottom of a freshwater lake, Fossil Lake, 52 million years ago!
Looking towards the Wasatch Formation, marked by claystone and siltstone.
The spur up to the quarry site leaves to the left if hiking clockwise.

Just shy of one mile I reached the spur trail to the quarry, which climbs steeply for about one-tenth of a mile. I absolutely loved the views on the short loop around the quarry site!

Looking up towards the quarry
Heading up the steep trail towards the stair section, which forms a small loop
Great views from the quarry of the trail
Getting giddy to geek out over some rocks!
“18-Inch Layer: The organic-rich limestone of the 18-inch layer formed in the deepest part of Fossil Lake. Over half of the fossils that come from this layer are complete and intact. Where you are standing, the 18-inch layer is gone. It was quarried before Fossil Butte National Monument was established.”
Heading up the stairs
“Volcanic Tuff: Erupting volcanoes periodically scattered ash that settled into Fossil Lake. Compacted ash or tuff layers, some only 1mm thick, are traceable throughout Fossil Basin. The thicker tuff layers are used as geologic marker beds. The minerals biotite and feldspar found in the tuff deposits have been radiometrically dated to 50 million years old”
“Organic-Poor Limestone: The sediments that make up this rock were deposited in shallow water. The layers are thick, indicating rapid sedimentation. As calcium-rich waters from rivers and streams mixed with alkaline lake water, calcium carbonate precipitated rapidly, diluting the organic matter. Fossils of shallow water inhabitants like juvenile fish, stingray, and crayfish are found here.”
“Fossil-Bearing Layers: When you look at the organic-poor limestone layer, do you notice any dark, thin horizontal lines ranging from 2-8 inches long? These are fossils. The fossils’ color is from staining by elements like iron (orange) and carbon (black/brown). Fossils are also found in organic-rich limestone.”
“Organic-Rich or Poor?: Is this layer organic-rich limestone or organic-poor? Remember that organic layers are dark in color and organic-poor limestone layers are light in color and thicker. Do you see any fossils?”
Time to head back to the main loop trail

I headed back down the spur trail and rejoined the main trail, continuing along the loop. The next cool thing I ran across was the Haddenham Cabin, which is on the National Register of Historic Places. This small A-frame cabin was built by fossil hunter David C. Haddenham around 1918 to serve as on-site shelter for himself and his family during their seasonal quarrying work. He actively quarried in the area of the present monument from the late 19th century to his death in 1968. 

A few spring wildflowers were making an appearance
The Haddenham Cabin
The cabin is pretty tiny! Definitely seems more like an emergency shelter than something intended to be lived-in for months!
Continuing down the trail and it started lightly hailing on me!!

A little over an hour I arrived back at my car, refreshed from my jaunt outdoors and finally exploring Fossil Butte National Monument outside of the visitor center!

Details:
All Trails Link
Date Hiked: May 15, 2025
Trailhead: Historic Quarry Trail
Total Mileage: 2.8 miles (Garmin Forerunner 255s)
Total Elevation Gain: 778 feet (Garmin Forerunner 255s)
Total Time Spent: 1 hour 3 minutes
Weather: Cool, cloudy, and 30mph wind gusts
Trail Conditions: Dry
Special Considerations: This hike is within Fossil Butte National Monument, but no entry fee is required. Fossil collecting is illegal. The trailhead is located 6675 feet (2035 m), and climbs over 700 feet so bring water and take it slow if needed. The trail is located in a desert with no shade, and can be very hot in the summer months. Trail is open year-round, but may be snowy and muddy. Leashed pets are allowed on the trail.

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Published by The Adventuring Heidi

Hi world, I’m Heidi! Adventurer, road trip fanatic, photography geek, waterfall chaser, geyser gazer, Iceland obsessed, Wyoming native, outdoor lover. I travel a lot personally and for work, and love capturing the awesome and awkward moments along the way.

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