In Borrego Springs light from the setting sun streams through the dust stirred up by off-road vehicles at the Ocotillo Wells State Vehicular Recreation Area nearly 15 miles to the east. Thanksgiving Weekend draws thousands of visitors to the park where it is legal to ride off-road vehicles on dirt roads, up dry washes, down canyons, and over hill and dale. Off-road activity and a bit of wind keeps the dust stirred up. The dust dome extends to the Salton Sea nearly 30 miles farther east and lasts for days.