BRUNEAU DUNES

If your passions lean toward downhill speed, powder snow and crowds of people this winter Sun Valley is the place to go. If your taste runs to solitude, walkable slopes and an even drier powder, a visit to south-central Bruneau Dunes State Park is in order.

Home to the tallest dune in the United States, the Bruneau Dunes rise out of a broad Snake River canyon that was carved from a cataclysmic flood 11,000 years ago. Water unleashed from the inland Bonneville Sea in northern Utah created the perfect basin for catching sand dropping out of the wind.

Sand has been collecting here there ever since and offers you a chance to live out your "Lawrence of Arabia" fantasies. The prevailing winds from the southwest and northeast counterbalance each other and the sand to build up as dunes rather than scattering across the landscape.

The main dune now stretches in a wavy pattern more than a mile-and-a-half-long toped by razor-back ridges that peak at 470 feet above the canyon floor.

Smaller straight dunes rising 40 to 80 feet high flank the big dune like tugs around an ocean liner.

The dunes and the adjacent lake attract more than a 1,000 people on hot summer days. But come winter, only a smattering of people are found wandering around the dunes on weekends, and during weekdays you are likely to be the only person there.

Situated in Idaho's semi-arid desert and rim rock country, the dunes receive less than ten inches of rain a year. And if a storm does blow through, the wet, hard sand has the benefit of providing firm footing for hikers.

Hiking the dunes takes some initial adjusting to as your feet quickly slide into the sand. The fine granules are a black and light-brownish color. The unique coloration is a result of nearby iron deposits that the wind weathered and skipped across the countryside.

A hike up the big dune and across its crest can be dune in a few hours, but it is best to take the whole day to explore and experience the mountain of sand, and flora and fauna that inhabit it and the wind that has shaped it.

The wind is omnipresent and a good wind-proof jacket is helpful when you start the climb up the dune. You quickly realize that even when it is not blowing, the wind has left its presence on the sand.

Tranverse wave patterns appear, giving way to whorls elsewhere, with other expanses exhibiting a smooth, unblemished surface. Depressions and pockets dot the dune, and a 200-foot-wide, 300-foot-deep crater appears where the wind has been blocked out.

Wildlife abounds on the dune and nearby water. Sand Dune Lake, created in the 1950s from water used for irrigating nearby fields, attracts shorebirds, ducks and geese that can be viewed from the dune. Ferruginous and red-tailed hawks float overhead and golden eagles perch on the dune's crest, outlined against the blue sky.

Many of the animals that live on the dune or that traverse it are nocturnal, but leave a wealth of information with their tracks in the sand. Black footed jackrabbits and deer prints can be spotted by the base of the dune. A coyote's track heads up the dune only to disappear in mid-stride as if it had magically vanished. A kangaroo rat's paw and long tail indentations look as if someone wrote hieroglyphics in the sand.

Cheat and bunch grass cling to the lower flank of the dune, fading out as you move upward. Bunch grass surprises you by reappearing higher up the dune, tucked away in depressions sheltered from the wind.

The sun provides for elongated shadows as you walk across the dune, especially in winter when the sun its lower on the horizon. It is as if your shadow has been cast by a fun house mirror. Your legs have become a pair of stilts and your body is narrow enough to fit in a fashion magazine swimsuit.

A climb to the dune's pinnacle provides you with a panoramic 360-degree view as you are above the canyon walls. Hikers can gaze up and down the Snake River canyon, over the tops of the surrounding plateaus and off to the Owyhee Mountains to the southwest and the Danskin Mountains to the north.

The descent down the steep slope is easy as the sand cushions your steps. The biggest danger is fighting the temptation to do somersaults all the way down the face of the dune.

The end of the day at Bruneau Dunes leaves you exhilarated, with an appreciation of sand you haven't had since crawling around a sandbox as a kid.