Bruneau Dunes State Park, Sand dune park in Owyhee County, Idaho.

Bruneau Dunes State Park is a state park in Idaho's remote Owyhee region featuring massive sand dunes and two lakes set in desert terrain. The landscape also includes wetlands and open desert areas that create a mix of different natural environments.

The area was shaped more than 15,000 years ago by a massive ancient flood that left sand deposits across the region. The dunes have settled into this basin and remained relatively stable for thousands of years since.

The park takes its name from the Bruneau River, which flows past the dunes; the river in turn carries the name of an early settler. Visitors today can watch sandboarders and sledders on the dunes, fish and swim in the small lakes, and join Friday and Saturday stargazing sessions at the park's observatory from mid-March to mid-October.

The observatory opens Friday and Saturday evenings from mid-March to mid-October. No motorized vehicles are allowed on the dunes, but climbing and sledding are permitted. Horseback riding trails of seven and nine miles circle the dunes.

The dunes stay relatively in place despite constant winds because winds from opposite directions balance each other out. This is unusual for dune landscapes, which typically move with the strongest prevailing winds.