That lowers the aquifer below the salt flats and reduces the amount of brine that rises to the surface, so natural restoration is minimal. Today, surface mining of the brine has largely ceased, but it is still being pumped out of wells on the mining company property by Intrepid Potash, current holder of the mining lease. Bonneville proponents have long argued that the salt should be returned to the racecourse once the potash has been extracted. The common salt is left behind and stored on the mining company’s property. There, potash is precipitated out of the brine. But since the federal Bureau of Land Management first issued mining leases in 1963, mining companies have been pumping the brine into facilities across Interstate 80, south of the salt flats. Potash is a component of the brine that bubbles up in the spring and thickens the salt layer. The Bonneville racing community believes that potash mining is most responsible for the salt flats’ degradation. They did a lot of damage but rekindled national interest in restoration efforts that have long been championed by Save the Salt and the Specialty Equipment Market Association, a trade group representing manufacturers of equipment used by racers. Circling at high speed, they ripped up the now-thin surface, creating deep ruts. The world was reminded of the salt’s vulnerability in 2018 when two Utah residents tore it up doing donuts in a modified Ford Crown Victoria.

(The current record is over 760 m.p.h., set in the Black Rock Desert of Nevada.)

At this length, the course is too short for the fastest racecars and record attempts. Now, in many places it is less than an inch thick and fragile.Īnd while the usable racecourse was once 13 miles long, it has now shrunk to about 7 miles. Tom Burkland, board vice president of the Save the Salt Coalition, composed largely of racing enthusiasts, says the salt crust was over four feet thick when he first raced at Bonneville in the 1960s. The crust has been growing thicker in this manner for thousands of years.īut the last 50 years have distressed the course. As the liquid evaporates, winds kiss the lake bed, leaving a smooth layer composed largely of salt.

The minerals are deposited on the surface when brine from an aquifer below rises in winter before drying in the spring and summer. The dry lake bed is composed of minerals - including gypsum, potassium chloride (potash) and an abundance of sodium chloride (table salt). The otherworldly white surface began forming at the end of the last ice age when Lake Bonneville receded.

Bonneville salt flats in winter