Hiking to the top of the dunes Photo: Scott Willoughby

Somewhere past the official UFO watchtower, beyond the local alligator farm and on the far side of the crystal and incense shops surrounding the New Age outpost of Crestone on Hwy. 17, we turned left, moving due south to due east like an archer's arrow piercing the metaphysical faŤade of the San Luis Valley. After another deliriously straight 20 minutes of asphalt, the spell was broken and we wound our way through the foothills of the Sangre de Cristo Mountains before coming to a halt at Colorado's greatest anomaly - the Great Sand Dunes National Monument.

Covering some 50 square miles and rising almost all of 1,000 vertical feet off the valley floor, the Great Sand Dunes are perhaps the most surreal sight in the state, like a swath of the Sahara grafted onto the side of the snowcapped Sangre de Cristos.

Johnny and I were here to ponder the mystic realm of this existential apparition au natural. In some half-dozen visits, I'd never really been able to wrap my mind around the Great Sand Dunes, either how they got there or, for that matter, why. I mean, they damn sure look pretty at sunset, but where's the water? What purpose did they serve?

Armed on this occasion with a roommate's 8-year-old snowboard and a can of silicone, I was bound and determined to find out.

While there's no shortage of colorful explanations as to why the massive sea of sand exists at a land-locked elevation approaching 8,000 feet, the truth they are teaching at the nearby visitor center is as boring as just about all geological revelations - the wind blew it there. After teaming up with water to scour the mountains on the west side of the valley, the omnipresent gale "supposedly" carries the sand northeast to the opposing mountain range and loses its punch when it hits the towering barrier. The result (if you believe the androids that the aliens left behind to spread such outlandish cock-and-bull) is one enormous sand box that's awful easy on the eyes.

As it turns out, it's also an epic snowboarding spot. Even without the snow.

"Look at all that freshy," Johnny joked as I strapped a backpack full of boots, water and the trusty snowboard to my shoulders. "Not a track in sight."

As we selected our route up and scouted various routes back down an enormous sand bowl, it became painfully obvious as to why the slopes remained untracked even this late in the afternoon. Indeed, my first time snowboarding the dunes was a seemingly endless exercise in epiphenomenalism, so I'll set the record straight now: the hardest thing about snowboarding on sand has very little to do with snowboarding, or should I say, sandboarding. It has a whole lot to do with hiking up steep, massive heaps of transient dirt with 30 pounds of gear strapped to your back.

Sure, sliding around on mounds of sand presents a unique set of challenges, but foremost among them is actually getting to the top of the mounds. Even on the ridges, steep slopes might require 20 steps to move 10 feet as your legs are swallowed by the loose granules of terra (non) firma forming them.

"It's steeper than it looks," Johnny reminded me as I experimented with a crawling technique I'd seen on the cartoons. "That doesn't work. I already tried it."

"Sure, sliding around on mounds of sand presents a unique set of challenges, but foremost among them is actually getting to the top of the mounds..."

Even after we had reached the summit of the third "range" nearly 1,000 vertical feet up, I could sense Johhny's doubt. He was only here for the hike, training for the "real" ski season a month away and insisting on taking photos of my white mouse run down the steepest section of the big bowl. "Otherwise," he explained, "you're not going to get enough speed."

I sat in the soft sand to strap on the snowboard before looking down a rollover face of more than 40 degrees and drawing in a dusty gulp of air. Johnny had set up just below, rested and ready to document the event. Here goes nothing, I thought, and pointed it south.

Slowly, the board etched its line through the sand, gaining obvious momentum with every inch. Soon enough, the sand began to feel like heavy spring snow and the familiar sensation of speed took hold. Better reign it in, I thought, as I attempted to check my momentum with a heelside turn before hitting the steepest portion of the slope. Almost immediately I felt the edge wash out and straightened the plank back down the hillside before losing control. Next epiphany: turning is not an option. Neither, I'm fairly sure, is crashing.