Spotlight on Parks: Castlewood Canyon State Park

It’s the evening of August 3, 1933. Sheets of rain pour down on the saturated ground around Franktown, CO. Cherry Creek is already bloated with water from earlier in the week and the additional rain sends it pounding, hammer-like against the Castlewood dam, causing it to give way. A fifteen foot high wall of water rushes all the way into Denver, initiating a massive and devastating flood, but, miraculously, only 2 people die.

The ruins of Castlewood dam at Castlewood Canyon State Park. Photo by Jamie Simo.
The ruins of Castlewood dam at Castlewood Canyon State Park. Photo by Jamie Simo.

You can still see the ruins of the Castlewood dam today at Castlewood Canyon State Park, a 2,303 acre park within the Black Forest region of Colorado, so-named for the number of ponderosa pines growing in the area. Established as a state park in 1964, Castlewood Canyon is a prime spot for rock-climbing, geology, and birding.

I visited the park last month with the objective of maybe catching a glimpse of a porcupine. Full disclosure: the porcupine were wily and I didn’t see a single one. I did see some spectacular snow-covered scenery though.

Castlewood Canyon sits on an ecotone, which is the transition zone from one ecological community to another. In Castlewood Canyon, this ecotone melds the prairie with the mountains. The meeting of these two communities has resulted in an amazingly diverse amount of animal and plant life within the park, including several extremely rare plant species.

On my hike along the Creek Bottom and Inner Canyon trails, I saw several mule deer and many birds. The highlight for me was the tiny canyon wren that popped up on a rock in front of me, clearly agitated by my presence.

Canyon wren at Castlewood Canyon State Park.  Photo by Jamie Simo.
Canyon wren at Castlewood Canyon State Park. Photo by Jamie Simo.

Though I visited in the winter, the summer is apparently a fantastic time to see the park as it’s a hot spot for turkey vultures which roost in the rocks along the canyon’s rim. Bears and mountain lions are also occasionally seen passing through the park so I’ll be sure to come back to see what the other seasons have to offer!

There’s no camping in the park, but visitors can enjoy Castlewood Canyon from 8am to sunset every day. Like all Colorado state parks, entrance to the park costs $7 or $70 for an annual pass. Additional fees for facility rentals for weddings (very popular here), picnics, or other gatherings can be found on the park’s website.

The Subnivean World

Subnivean. The word sounds like it could be referring to the homeworld of a race of space giants in a science fiction novel, but it’s actually a very down-to-earth term and this time of year is the perfect time for its use. “Sub” of course means below. “Nivean” comes from the latin word “nives,” which means snow. So “subnivean” means “beneath the snow.”

A prairie vole at Coyote Ridge Natural Area in Fort Collins, CO. Photo by Jamie Simo.
A prairie vole at Coyote Ridge Natural Area in Fort Collins, CO. Photo by Jamie Simo.

You wouldn’t know it to look at it, but under that fresh layer of new-fallen snow lies an entire ecosystem. Unlike chipmunks, rodents like mice and voles don’t hibernate during the winter and, right beneath your feet, they may be busy carving out elaborate tunnels leading from one clump of tasty grass or seeds to another. Some of those tunnels are so elaborate they consist of a number of chambers for different functions like eating, sleeping, caching food, and urinating.

The secret of the subnivean world is the snow itself. Snow is actually a fantastic insulator as long as it’s not too wet, which you may know from learning about Eskimos and their igloos. That’s because snow is comprised of ice crystals with pockets of air between them. This trapped air holds onto heat, meaning that the air between the ground and the first layer of snow pack stays fairly constant around 32 degrees Fahrenheit no matter what the temperature or weather conditions above.

Diagram of the subnivean zone by Marco Cibola. http://archive.audubonmagazine.org/truenature/images/ice_Castle-marcocibola-lg.jpg
Diagram of the subnivean zone by Marco Cibola. http://archive.audubonmagazine.org/truenature/images/ice_Castle-marcocibola-lg.jpg

This fairly constant, relatively warm air allows insects and microbes to survive in some of the harshest conditions around, which, in turn, provide food for those before-mentioned rodents. The snow also helps protect small mammals by screening them from predators, though it’s not a magic bullet. Many predators, like owls, have hearing so sensitive that they can detect the sounds of their prey moving under the snow. The great grey owl, for instance, can hear a mouse under up to 18 inches of snow!

So, now that you know about the subnivean world, try slipping the term into conversation the next time you’re at happy-hour and see what happens. Who knows, you might find you’re the life of the party!