At Bruneau Dunes State Park, off I-84's Mountain Home exit, massive sandpiles remain trapped in a semicircular basin, due largely to opposing wind currents. The park contains the tallest freestanding dune (470 feet) in North America.

Be sure to stop by the visitor center where you'll find a detailed exhibit on the area's desert denizens, among them the coyote and the golden eagle, along with fossils from former residents such as the mammoth.

QUICK FACT Discovered in 1952, the endangered Bruneau hot springsnail is the size of a pencil eraser and is found only in thermal springs along a five-mile stretch of the Bruneau River.

The Bruneau Dunes Observatory houses a giant 25-inch Obsession, the largest telescope in the West that's accessible to the public. Park staff and members of the Boise Astronomical Society offer a multimedia introduction to the stars on weekend evenings from March through November for $3 per person.

The dry air in Bruneau not only makes for great stargazing, but also helps preserve rocks and artifacts. About eight miles west of the park, near C.J. Strike Dam, you can view native rock art that was rescued from the reservoir before it was filled.

Bruneau is also the last stop before you head into the nearly 3 million-acre Owyhee-Bruneau Canyonlands. This high-desert plateau is dotted with small lakes where sturgeon, crappie, and largemouth and smallmouth bass are plentiful. You'll find gear for sale at the Fishin' Hole Bait and Tackle in Bruneau.

Plunge into this wilderness on a guided rafting run down the Bruneau River, which slices through the region. The challenging white water rushes past rust-hued canyon walls that rise to heights of 1,000 feet.