The Imperial Sand Dunes, also referred to as the Algodones Dunes, are the largest mass of sand dunes in California. This dune system extends greater than 40 miles along the eastern edge of the Imperial Valley agricultural region in a band averaging five miles in width. Rising to heights of more than 300 feet above the surrounding desert floor, the dunes are a well-known landmark to local residents and the thousands of highway travelers who pass by them every year. While summer temperatures shoot above 110°F, and the annual rainfall averages less than two inches, the mild climate between October and May is a magnate to tens of thousands of off highway vehicle (OHV) enthusiasts to the area. Thanksgiving week-end is an especially popular weekend.
The sand dunes afford many fantastic opportunities for recreation.  OHV activity is allowed on more than two-thirds of the sand dunes.  The best known sites are Glamis(south of State Highway 78), Buttercup, (south of Interstate Highway 8), Dumont Dunes to the north, Gordon's Well and Olgiby.  Competitions and events such as sand drags, closed-course racing and hill climbs are sometimes conducted in the dunes. These events require a Special Recreation Use Permit from the BLM. Commercial filming or photography, promotional events and mobile vending also require permits. Dunes recreation visitors must pay $25 per week or $90 for a season pass. All OHVs must have a flag or mast.  The maximum speed limit is 15 mph on roads in campgrounds. Glass beverage containers are prohibited in the Imperial Sand Dunes Recreation Area, for safety reasons.