Any number of racetracks hold claim to colorful back stories, their heritage of championships battled fiercely to the finish. But it is doubtful that any racecourse has a history to match that of the Bonneville Salt Flats.
Around 15,000 B.C., during the last ice age, there was an inland sea in northwest Utah roughly the size of Lake Michigan. Over the next 11,000 years, the water evaporated as the climate warmed, leaving a thick layer of glistening salt near what is now Wendover, a town on the Nevada border some 120 miles west of Salt Lake City.
Left untouched, the hard surface might maintain its cap, up to seven feet thick in places, for millenniums to come. But today the crust on the protected area — it is listed in the National Register of Historic Places — is receding, down to just a few inches in some areas. Veteran racers have said that speed trials on the salt flats could be forced to end in less than a decade.
Named for Capt. B.L.E. Bonneville, who explored the area in the 1830s, the salt flats once covered an area of some 96,000 acres. Winter rains raise the water table slightly above the salt; when the water evaporates in the spring, it leaves a smooth surface nearly as hard as concrete.
Bonneville's advantage as a site for speed runs was recognized by W.D. Rishel in 1896, who was scouting a bicycle racecourse. Since then, vehicles have set scores of land-speed records there. In 1935, the salt flats became known internationally when a British racer, Sir Malcolm Campbell, pushed the land-speed record past 300 mph.
While a number of trials are scheduled for the salt each year, the best-known event is Speed Week, usually in mid-August.
How long this event can go on is unknown. Because the entire Bonneville basin is connected by a giant aquifer and artificial salt brine ditches, mining operations across Interstate 80 have shrunk the salt's expanse. The mining removes potash and magnesium, depositing brine on the wrong side of the highway. The salt flats now cover about 30,000 acres; the 13.5-mile straight has been cut to seven.
Although the salt flats were established as an Area of Critical Environmental Concern in 1985, the federal Bureau of Land Management allowed mining to continue, and conditions deteriorated. In the 1990s, the racing community started a coalition, Save the Salt, that persuaded the mining company to pump leftover brine back onto the flats.
During a pilot pumping program in 1997-2002, the salt crust began to get deeper, firmer and wider, with the high-speed straight briefly back up to 13 miles. But the program concluded and voluntary efforts to continue it were spotty.
Now there may be reason for cautious optimism. Intrepid Potash-Wendover recently acquired the mining operation and a restoration has begun. In recent months, Intrepid has pumped an estimated half-million tons of salt onto the flats.