Bruneau Dunes State Park in southwestern Idaho preserves an unusual landscape where desert, prairie, lakes, marshes, and dunes meet across 4,800 acres. Its best-known feature is a 470-foot dune identified as North America’s tallest single-structured sand dune. Unlike many dunes, these formed near the center of a natural basin that has trapped sand for more than 12,000 years, possibly beginning with material left by the Bonneville Flood about 15,000 years ago. Balanced winds help keep the dunes relatively stable. Established from land first purchased in 1967 and later expanded, the park also supports wildlife, low-impact recreation, natural history education, and public stargazing at its observatory.