Boise, Idaho ? For nearly two centuries, a vast expanse in the corner of present-day southwestern Idaho and portions of neighboring states was considered a sagebrush wasteland of little interest.

But the adventurous are starting to find out about the Owyhee country, which features whitewater rivers rushing through deep gorges, juniper-covered peaks, multicolored geology and millions of acres of Old West solitude to experience.

It’s considered the largest undeveloped, unprotected wildlands in the lower 48 states.

“The area is such an amazing, undiscovered gem,” says Roger Singer, director for the Sierra Club’s Idaho chapter. “Relatively few people have found it yet. It’s just not on the map, which is good in a sense. The area has stayed relatively pristine, compared with our overdeveloped, loved-to-death national parks.”

Volcanic activity starting 14 million years ago created the largest concentration of rhyolite rock in the world. The immense Lake Idaho formed and later drained, slicing the gorges of the Owyhee, Bruneau and Jarbidge rivers.

Humans have been in the area for 15,000 years, including the Shoshone and Paiute tribes. In 1818, white trappers accompanied by several Hawaiians entered the region. The Hawaiians disappeared as they were exploring a river that was later named the “Owyhee,” the phonetic spelling for Hawaii at the time.

Basque sheepherders from Europe and cattlemen have worked the area since the 1800s. Miners sought gold and silver in the Owyhee Mountains beginning in the 1860s. They built communities like Silver City, a jewel of a ghost town near the Owyhee County seat of Murphy.

Vibrant ecosystems

Biologists consider the Owyhee to be one of the most biologically rich high-desert ecosystems in the country. It’s home to peregrine falcons, golden eagles, sage grouse, California bighorn sheep, pronghorn antelope, cougars and the rare redband trout.

Rafters float along the Bruneau River in the Owyhee Canyon. Biologists consider the Owyhee to be one of the most biologically rich high-desert ecosystems in the country.

It also features native sagebrush and bunchgrass ecosystems, plus rare plants such as the Owyhee River Stickseed, Anderson’s buttercup and Inch-High Lupine.

The region has remained relatively untouched because access into the area was either via primitive roads, on foot or horseback. That is starting to change along the edges closest to the Boise Valley. Hunters, motorcyclists and all-terrain-vehicle riders are venturing farther and farther into the realm.

While much of the Owyhee is still untrammeled, conservationists, ranchers, county officials, off-road enthusiasts and others are meeting in a task force to determine its future.

Conservation groups endeavored to have the Owyhee-Bruneau Canyonlands designated as a 2.7 million-acre national monument. Yellowstone National Park encompasses 2.5 million acres.

Rivers run through it

Hundreds of miles of the Owyhee and Bruneau rivers, with all their forks, are under study for preservation under the federal Wild and Scenic River system. A big draw these days is rafting or kayaking down those desert rivers.

The Owyhee River flows west from headwaters in Idaho and Nevada into Owyhee Reservoir in Oregon. There are several stretches that can be run.

The Bruneau River is referred to by paddlers as the “Sistine Chapel” of all river canyons.

It runs through a gorge up to 800 feet deep with rocks that resemble Bryce and Zion national parks.

The rapids on the two range up to a perilous Class V, according to the water levels. The rivers can be navigable from late March through mid-June, although Idaho’s long-running drought narrows that window considerably. A number of private outfitters operate on the streams.

Wildflowers grow along the canyon of the Bruneau River, in the Owyhee country of southwestern Idaho.

Reaching the river put-ins, or other far-flung places in the Owyhee country, can be arduous or nearly impossible during spring rains.

“It’s for people looking for a different kind of adventure which requires route-finding skills, a hardy vehicle and a willingness to be out in the middle of nowhere,” Singer says.