The dune rises from the forest floor in a pale slope as steep as the face on a pyramid. Its leading edge has engulfed the Devil's club and alders at your feet, with leaves colored by a dusting of fine sand. A tiny avalanche slips down the wall before you. You suddenly realize that this dune is alive and crawling forward even as you watch. It has been slouching deeper into the woods of Kincaid Park near Anchorage's southwest corner over decades, a rough Ice Age beast engulfing the vegetation inch by inch by inch. A chiller in slow motion -- if you're a tree.
So you climb. (And how can you not?) It takes 160 soft, wallowing steps to lurch from the base to the highest point. The sand sloughs into your shoes as you go -- gorgeous smooth brown grains speckled with white and black, all of it ground from the Chugach Mountains bedrock over uncounted eons. The sand feels clean and cool to your hands when you're forced to crawl. You want to bury your arms to the elbows like a child at the beach.
The summit opens to a stunning 10-mile-long vista of Turnagain Arm and vast tide flats and the forest crown of the park. You see that you are standing as high as the peak of the 45-foot cottonwoods, with a raven's view of the terrain. Entire trees have been buried in the sand beneath your feet. Some of the dead trees emerge on the windward side, their trunks now as bleached as bones. Below you sprawls a former gravel pit and present motor sports area that keeps the vegetation stripped off the ancient deposit of sand. In a sense, it is this accident of human use that created and continues to replenish an active dune under the guiding force of the prevailing wind.
Geologists will tell us that the dune is the startling legacy of Anchorage's Ice Age past, one tiny portion of a complex, 300-foot-deep deposit of gravel and silt left behind when the immense glaciers retreated for the last time more than 10,000 years ago. The bluffs along Anchorage's coast are largely made up of such sand, but it only surfaces in a few locations.
The dune has the classic asymmetrical shape, a demonstration of the same natural processes you would find at work in the heart of Arabia. Wind pushes loose grains and rolls them up hill, gradually creating the undulating windward slope. When the grains reach the brink, they hit the wind shadow and fall steeply down the leeward face. In profile, it looks like hill cut in half.
Visiting is easy. Park at the Jodphur Road entrance to Kincaid Park near the west end of Dimond Boulevard. Take the main trail west, following the light poles until you reach pole number 13. Take the obvious well-trod side trail to the left or south. Be careful that the Devil's club doesn't scratch your arms. In about two minutes, you will be standing in sand.
Contact Doug O'Harra at doug(at)alaskadispatch.com.