Wellington through the ages

By Gary Raham
Wellington Correspondent

Happy 100th birthday, Wellington! A hundred years is a long time, but not too long. I can relate that venerable age to people and events important to me: my father was born in 1905, too. Longer time intervals get progressively harder to imagine, unless some physical reminder pops up, like the mammoth tusks and molars unearthed in a Wellington housing development five years ago, or the 10,000 year-old Lindenmeir Folsom points and bison bones found just north of here in 1924.

What would this place we call home have looked like at various points in deep time--times during which mountains rise and wash to rubble, and oceans come and go? The colorful, layer cake mountains and rolling plains we admire sometimes contain the clues that let geologists recreate these ancient landscapes. Some temporal stops might include the following:

• 10,000 to 20,000 years b.p. (before the present): Not a Safeway in sight. If you are a paleo-Indian at this time, best to be able to make or barter for the handsomely fashioned points which, when firmly attached to the haft of a spear, could bring down bison, which stood 7 foot at the shoulder, or other ice age fauna like camels, giant sloths and mammoths. Keep an eye out, of course, for saber-toothed cats, short-faced bears, giant wolves and other predators that might want to invite you for dinner. Gather edible plants watered by rivers and streams fed by melting mountain glaciers.
• 2 million years b.p.: Not a human in sight. The mountains would have looked much the same, although covered with considerably more snow during the height of glaciations. Ice reached depths of 1,500 feet in places.
• 5 million to 7 million years b.p.: A mountain growth spurt helped form favorite canyons like the Poudre and Big Thompson.

• 32 million years b.p.: Wellington would have been very hard to recognize. The modern Rockies, only half formed, poked through lush forest vegetation. Vast herds of vaguely pig-like grazing animals called oreodonts found the area inviting for millions of years, finally leaving the last of their bones in sediments near the small town of Grover, northeast of us.
• 70 million years b.p.: The Rockies are just beginning their slow rise. Wellington is beachfront property for dinosaurs that can look east over the waves of a quiet inland sea that will ultimately leave shale deposits up to 14,000 feet deep to aggravate modern gardeners. Today, the shells of clams turn up along road cuts, giant fish bones and scales get quarried along with limestone for cement, and now and then a dinosaur bone erodes free of sediment, like those of the "Masonville monster" (a relative of the meat-eating dinosaur, Allosaurus) found west of Horsetooth Reservoir some years ago.

Wellington's history goes much deeper, but fortunately we don't have to dig for it. As the 1.8 billion-year-old granite that forms the core of the Rockies rose, it pushed up layers of sediments extending back to the days of a former mountain range (the ancestral Rockies) that existed here 300 million years ago. These layers have split and been pushed apart to stand as ragged ridges--the so-called "hogbacks" that stretch along Colorado's front range. The oldest, sedimentary rocks lie nearest the mountain granite. The waters of Horsetooth Reservoir nestle among these hogbacks, sitting atop marine Paleozoic rocks 250 million years old. Rocks belonging to the "age of dinosaurs" rise to the east, culminating in a 100-million-year-old Dakota sandstone cap atop Reservoir Ridge, which is eroding back to beach sand.

Happy birthday, again, Wellington. You're not so old, after all, at least as measured on the geologist's deep time clock. May you build a rewarding future based on such solidly beautiful bedrock.

Useful references for local geology and natural history:

Chronic, Halka and Williams, Felicie. Roadside Geology of Colorado, 2nd Edition. Missoula, Montana: Mountain Press Publishing Co., 2002.

Colorado Geological Survey. Messages in Stone. Denver: CGS, 2003.

Johnson, Kirk R. and Raynolds, Robert G. Ancient Denvers. Denver: DMNS, 2001

Evans, Howard Evans and Alice. Cache la Poudre, the natural history of a Rocky Mountain River. Boulder: University Press of Colorado, 1991.