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The ‘Living Dunes’ Reflect Changing Moods of WinterBy Tom Baake
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With mysterious-looking yardangs in the foreground, a visitor takes in the view from atop an Oregon Dunes ridgeline.
When it comes to sweeping panoramas of sea, sand and sky, few places rival the Oregon Dunes National Recreation Area north of Coos Bay. It’s especially awesome from higher vantage points, when miles of rolling dunes and a wide-open sky merge at the horizon line – or at the Pacific Ocean, if you happen to be looking west. In addition to the moody, windswept dunes, you can enjoy intriguing features with names like “tree islands” and “yardangs.”
To make matters even more interesting, the whole look of the place changes with the seasons. It’s easy to understand why they’re often referred to as “The Living Dunes.” This has a lot to do with the wind, which typically blows from the north in summer and from the south in winter, and can both sculpt the sand and smooth it over.
Wind actually creates several kinds of dunes. Oblique dunes are the largest and most impressive. “Oblique” refers to their crests, which are angled on their steep side to seasonal wind directions. Occurring in parallel series, these dunes can rise as high as 180 feet, with lengths up to a mile. The tallest is about 500 feet above sea level.
In winter, the south-facing slopes receive the wind’s brunt, resulting in smooth contours. On the north side, however, the contoured sand can dramatically drop away, creating what’s called a slip face.
Summer transverse ridges (or transverse dunes) are as the name implies a summertime phenomenon, the result of northwesterly winds that create the familiar softly-sculpted, wave-like patterns of the Oregon Dunes. The crests of these 5 to 20-foot high dunes are perpendicular to the wind direction, but because they rely on dry surface sand and dry summer wind to maintain their appearance, they’re often blown away when the wind direction changes in winter.
Parabola dunes occur when winds create blowouts in unstable areas of the coastal forest. Strong winds erode the vegetation-covered surface to bare sand, which is then carried downwind, creating U-shaped ridges. In her 2008 guidebook, “Secrets of the Oregon Dunes,” U.S. Forest Service Oregon Dunes interpreter Dina Pavlis calls parabola dunes “one of the more interesting features of the dunes because they are the dune process in motion.”
The aforementioned tree islands are remnants of forests, now completely surrounded by sand and in the process of being “taken over” by the dunes.
Yardangs occur in wintertime on east-west running ridges. Strong winds relentlessly carve channels and otherworldly-looking formations. The result can also look like a smaller version of the eroded sandstone bluffs of the Desert Southwest.
While the Oregon Dunes are obviously comprised of sand in its various seasonal aspects, it’s really all about water. Beginning, of course, with the ocean, which continues to deliver and redistribute the sand along beaches.
Geologists currently think the sand started as rocks and small stones from both the distant Cascade Mountains as well as the closer-at-hand Coast Range that washed down to the sea to be tumbled and crushed and ground down over the eons. In some cases, the sand partially blocked streams and estuaries, creating the many lakes of “Dunes Country.”
All the lakes have outlets either to the sea or to other lakes whose outlets eventually end up at the ocean. Not, however, before some of it recharges a vast aquifer beneath the Oregon Dunes, or evaporates to create even more water.
Waterways that exist to this day are a fun way to explore the Oregon Dunes, such as on the Siltcoos River Canoe Trail south of Florence, or Ten Mile Creek near Lakeside.
Others enjoy the dunes in or on conveyances that range from all-terrain vehicles to sandboards to horses. There are also many places closed to vehicles where visitors can wander afoot for hours and miles.
You can also take in many of these features from the comfort of your vehicle at such places as the Umpqua Beach access in Winchester Bay. Just follow the signs on Salmon Harbor Drive to the Umpqua Beach access of the Oregon Dunes National Recreation Area and go south to road’s end. Here you can see examples of different kinds of dunes as well as a classic tree island.
And who knows? Maybe you’ll get inspired to do a bit of wandering – you can even take home some sand in your shoes as a souvenir . . . .
(Shopper columnist Tom Baake is author of regional guidebooks.)
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