The closest thing to the Sahara you'll find in the Pacific Northwest is the Oregon Dunes, a strip of super-fine sand, four kilometres wide, 64 kilometres long, 150 metres high in places, running the length of one of the most picturesque seascapes on the entire coast.

The largest coastal dune system in North America, it attracts geologists who come to study the unique mix of topography and terrain, naturalists intrigued by the wide range of flora and fauna, and hikers and campers drawn to the area's natural beauty. Off-road enthusiasts come for the sheer joy of racing their machines across acres of open sand.

The story of the dunes began 6,000 years ago, give or take a century or two. Born from the eroded rock of the distant Coast Mountain Range and brought to the ocean by the region's many rivers, the sand was driven ashore by winds and waves. As it advanced, it buried the pines and spruces of the coastal forest, collecting in a massive heap about 5,600 hectares in area.

Standing alone on the top of a big dune, a stiff summer breeze blowing in your face, you can experience this action firsthand. Gusts send tiny bits of quartz and feldspar off the edge of the dune and down the back slope. Grain by grain, the sand moves forward.

At least, that's the way it's supposed to be. But with the invasion of non-native European beach grass (Ammophila arenaria), the natural life cycle of the dunes is changing. Planted in the 1930s to stabilize the sand and prevent it from blowing into salmon-stocked estuaries, the grass has done its job all too well. As a result, the dunes are slowly being starved of sand.

The dunes aren't going down without a fight, however. A number of government and volunteer programs are currently under way to uproot the beach grass and return the dunes to their former state. In addition to removal by hand, the Forest Service and the Oregon National Guard are collaborating to mechanically remove the grass from some 109 hectares of beach. It's hoped such efforts will restore open-sand habitat for shore birds such as the endangered western snowy plover.

The best way to appreciate this battle between vegetable and mineral is to hike one of the many trails that line both sides of the coastal highway between the towns of Florence and Reedsport. Some of the most interesting can be found around the Oregon Dunes Overlook, located about 16 kilometres south of Florence. As its name suggests, the overlook is a rest stop and picnic facility whose main feature is a large deck built on a ridge above the open dunes. Standing on the deck, facing the sea of sand, you get a sense of what makes the Oregon Dunes a unique place.

The overlook is also the starting point of the Tahkenitch Creek Loop, an intriguing nature trail that will take you through the distinct topographical zones of the dunes. Starting at the northern end of the overlook, the trail winds down the ridge through the coastal forest and out into the open sand. From there, you hike across the dunes and through the wide deflation plain, then over the foredune to the beach. Marching south along the shore, you pass protected habitat for the snowy plover, finally cutting inland near the mouth of Tahkenitch Creek. A hike along the creek takes you across wetlands and through a large tree island””an isolated pocket of pines and spruce holding out against the sea of sand””until you cross the dunes again to end the trail at the foot of the overlook deck. Each zone is home to a distinct range of vegetation and wildlife; following the transitions from one zone to another is a fascinating study in both biology and geology.

Through the trail is only 5.6 kilometres long, it will take some time to travel. Make no mistake: hoofing your way through the deep sand can be fun, but it's also hard work. In some areas, the large wooden route markers are easy to find. In others, they can be obscured by undergrowth or partially buried by the sand. Miss a marker and you could find yourself wandering through the parched landscape until you pick up the trail again. All part of the fun, although it can make getting back to civilization a bit of an adventure.

For those who like their adventures motorized, there are numerous opportunities to rent dune buggies and ATVs near the towns of Florence and Reedsport. About 2,800 of the dunes' 5,600 hectares are open to off-road vehicles, but strict prohibitions keep vehicles from ecologically sensitive areas.

However you get to the top of it, standing on a 60-metre dune and watching the sun set into the Pacific is an experience to remember. But it's hard not to feel a sense of loss at the same time. The dunes are not only a spectacular piece of our coastal heritage, they are a warning about the consequences of ill-considered environmental decisions. Global warming, melting polar ice, deforestation””these may be the environmental problems of our time, but out here in the sea of sand, it is the decisions of 75 years ago that are causing catastrophe.

ACCESS: The Oregon Dunes are part of the Oregon Dunes National Recreation Area, situated along Highway 101, the Pacific Coast Scenic Byway; the towns of Florence and Coos Bay mark the area's northern and southern borders. From Vancouver, plan on an eight- to 10-hour car trip. Stay alert to the view as you drive””you'll be able to see some of the larger dunes peeking through the trees. If you plan on stopping in at the Oregon Dunes Overlook, you'll need to pony up US$5 for the National Forest day-use fee. The fee covers all National Forest day-use fee sites until midnight of the date purchased. For those looking to stay a little longer, camping opportunities are plentiful in the region's national and private campgrounds, but be sure to book in advance if you plan to visit during the summer. Sorry, no camping on the dunes themselves.