St. Anthony Sand Dunes
St. Anthony Sand Dunes encompasses 10,600 acres of BLM public land 8 miles west of St. Anthony in Fremont County, Idaho, managed by the Upper Snake Field Office, a dune system in the heart of the Snake River Plain agricultural belt that rises unexpectedly from the surrounding potato and grain farm country to become one of the largest OHV dune destinations in the Mountain West. The dunes are formed from white quartz sand deposited by the Snake River over thousands of years and subsequently rearranged by the prevailing southwestern winds, creating crests that reach up to 400 feet above the valley floor. The white quartz sand color is visually distinctive: in midday sun the dune faces reflect a brightness that contrasts sharply with the dark basalt rimrock of the Snake River Plain that surrounds the dune field on three sides. OHVs, ATVs, motorcycles, and dune buggies are permitted in the designated open-riding area; Idaho OHV registration is required for all machines. The area's proximity to Yellowstone National Park, approximately 90 miles to the northeast, makes St. Anthony Dunes a viable component of a Yellowstone-region outdoor recreation trip for riders who want to combine dune riding with backcountry touring. The season runs from late spring through early fall, with summer being the primary high season, sand temperatures can exceed 150°F in the height of July and August, so morning and evening rides are preferable in peak summer. Camping is available within the BLM area. Contact the Upper Snake Field Office in Idaho Falls for conditions (208-524-7500).