The Great Sand Dunes: A mirage come true in Colorado
Driving toward the Great Sand Dunes National Park and Preserve, you start to see tan ripples at the base of towering, snow-covered mountains, like a mirage wavering on the edge of your consciousness. Are they really there?
In a crescent on the west side of the Sangre de Cristo Mountains, blown by the winds, are the tallest sand dunes in North America, an incongruous Lawrence-of-Arabia-like desert trapped in south-central Colorado.
Most of the 330-square-mile sand deposit is covered and stabilized with plants, and unrecognizable as dunes. But 11 percent is exposed, recycling endlessly.
To get to the dunes, you first have to cross Medano Creek, which curves around the dunes, spreading out hundreds of yards wide so it’s only inches deep. The creek flows in surges as it builds, then breaks, sand dams, called antidunes, on the creek bed. Medano is one of two swift, shallow creeks that border the dunes, feeding underground aquifers, creating rich habitats and in some parts of the year not visible above ground. The other is the Sand.
When we arrive around 8 a.m., the water is so cold, it actually hurts my feet as we wade quickly across and head toward High Dune, 699 feet tall.
The dunes were deposited over hundreds of thousands of years with sand from the San Juan Mountains, more than 60 miles west, mixing with larger pebbles from the Sangre de Cristos in a huge lake that once covered the San Luis Valley. As the lake vanished, southwesterly winds blew the sands up against the Sangre de Cristos, and a cycle of regeneration began. Melting winter snows from the mountains swelled the creeks, washing sand downstream, then southwesterly winds blew them back toward the mountains. At the same time, northeasterly winds snaking through the Cristos pushed the sands back on themselves, building them into the tallest dunes in North America.
We start up the side of High Dune, which is really a series of taller and taller dunes, ridges and valleys. The promised reward, a 360-degree view of the 36 square miles of dunes.
There is no “trail.” It’s every climber for themselves. The slopes lead to multiple intermediate ridges, where the sand is churned from converging climbers. We arrived after an overnight storm that soaked the top several inches of sand, creating a more solid foothold, and we traverse the lower slopes on the pristine areas, our feet only occasionally breaking through the damp crust.
In the summer, sand temperatures can reach 140 degrees and park brochures warn of burning feet. Storms bring deadly lightning. We have arrived at a perfect moment in between.
The dunes host seven insect species that live nowhere else in the world, including the disco-colored Great Sand Dunes tiger beetle. The only mammal that can survive is Ord’s kangaroo rat. A few plants like Prairie sunflower, Scurfpea and Skeletonweed. West and south of the dunefield are salt-encrusted plains of sabkha, which include white, crusty sand and wetlands that attract sandhill cranes and American white pelicans.
We are joined by families with kids dragging sand boards to fly down the steep slopes, a lone repeat hiker who marveled at the conditions, saying he’d already saved a half hour on his way to making it to the top for the first time, and a group of tattooed, braided, 20-somethings perfumed with Colorado’s recreational herb.
There were shorts and crop tops, long hiking pants and long-sleeved shirts, cobbled together capes, hiking boots, sandals and bare feet, baseball caps, straw hats and wide-brimmed sun shades.
As the slopes got steeper, the crust gave way, our feet sliding down one foot for every two we advanced. Climbers slowed. Kids vaulted off ridges, tumbling and somersaulting down the slopes as parents stood to lower heartbeats and refill lungs.
“Each ridge looks like the top, then there’s more,” one climber wheezed to his group.
About two-thirds of the way up, I gave in to the Goddess of the Dunes and sat down, then lay down, contemplating her beauty from a prone position. Tom hiked closer to the top, returning to collect me about 30 minutes later.
No one knows the exact age of the dunes, but experts estimate they are about 440,000 years old.
In 2004, the Great Sand Dunes National Park and Preserve was established, combining the 32,600 acres of the open dunes, and another 40,595 in the Sangre de Cristo Wilderness, mixed conifer forests to alpine tundra up to 13,000 feet, which includes the headwaters of the Sand and Medano creeks.
The way down is worlds easier than the haul upward. Each step down, your dug-in heel slides several feet, the only effort required is to lean back so you don’t tumble forward. By the time we returned to Medano Creek about two hours later, my feet were hot and the water was the perfect temperature.