Tom Ross' column appears Tuesdays and Saturdays in Steamboat Today. Contact him at 970-871-4205 or tross@SteamboatToday.com.
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Standing on a low ridge, soaking up the views of sagebrush north of Kremmling, it's difficult to imagine large numbers of armored squid hunting their prey, mating and dying on this dusty ground.
It really did happen, just 70 million years ago, give or take a few. And the evidence is plain to see for any moderately adventurous family with a high-clearance vehicle. Given decent weather, you could stop by the Kremmling Cretaceous Ammonite Locality on your next trip from Steamboat Springs to Denver to watch the Broncos lose to a mediocre football team.
The ammonites are dramatic fossils that are easy to find just north of Wolford Mountain Reservoir.
Kirk Johnson wonders out loud how many passing motorists appreciate the profound visual evidence along this stretch of U.S. Highway 40.
"I often wonder how many people drive from Kremmling to Steamboat or Muddy Pass, see all these shales and realize that this was once the floor of an ocean," Johnson said Monday.
He is vice president of research and collections, and chief curator at the Denver Museum of Nature and Science. He also is among the scientists studying the ammonite fossils.
Before the Rocky Mountains were thrust thousands of feet into the blue Colorado sky, Middle Park lay along the edge of a vast ocean that covered a good chunk of North America.
The Kremmling ammonites, a strange, highly mobile cross between snails and squid, probably weren't the biggest predators in that prehistoric ocean, but they were bigger than any snails you and I have ever seen. Some of the fossil remains at KCAL are 2 feet across.
That's what I call a mean escargot! Please pass the butter.
All that remains of the giant snails are the impressions left behind by their spiral shells.
Almost all fossils are found in sedimentary rock, and the ammonites north of Kremmling are located in a band of marine fossils entrapped in Pierre shale. Johnson said that when the ammonites died, their remains precipitated calcium carbonate, which caused the surrounding mud to harden rapidly. Today, the fossils are found in solid rock concretions that aren't discernible from boulders to the uneducated eye.
The Kremmling ammonite site is noteworthy because nowhere else have researchers found such a large concentration of fossils. Almost 300 have been mapped.
Johnson said one theory is that this was a spawning ground. However, he is quick to say that is just speculation. Researchers know for certain that there are many more female than male fossils at the site because the former are four times larger than their counterparts.
The ammonites disappeared at about the same time as the dinosaurs, in the late Cretaceous Period. In geologic terms, it wasn't that many years before the rise of the Rockies.
So, what can we learn from the fossil record?
"The drama of this specific place is remarkable," Johnson said. "There was a sea in this part of Colorado 75 million years ago, just before there were mountains. And a major, diverse group of animals like the ammonites disappeared completely. Things changed dramatically."
If you visit the ammonites, be forewarned that collecting fossils within the fenced boundaries of KCAL is prohibited by the Bureau of Land Management and punishable under federal law. You should also avoid the area when the soil is wet. For the last mile of unpaved road, a high-clearance vehicle is a necessity because of a high center in the two-track path.
Driving from Steamboat, begin looking for a left turn on Grand County Road 25 when you come within about five miles of Wolford Mountain Reservoir. You'll see the small blue sign at the bottom end of the long valley where the rancher stores his hay in loose stacks.
After the turn, it's a short drive to the bridge over Muddy Creek. Soon after, you'll encounter the confusing intersection with GCR 26. Bear left and follow 26 for almost three miles to the left turn on the two-track road.
Or, for more complete information, contact the Kremmling office of the BLM at 970-724-3000.
Even if you never wander off the paved road, you can marvel the next time you drive this stretch of lonely highway that strange-looking creatures once lived here on the bottom of the sea.
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