Salt of the Earth

The man above might seem to be wading into a huge body of water. But it is really a giant puddle just a few inches deep. And underneath lies an even more unusual surface: a vast flatland of salt.

Welcome to the Bonneville Salt Flats, one of Utah’s rare natural features. The surface of this 30,000-acre area is a layer of salt crystals up to 5 feet thick. Most of it is the same stuff that’s in the shaker on your dinner table: sodium chloride.

This place was once the site of Lake Bonneville—an immense ancient lake. For thousands of years, it covered one-third of what is now Utah, plus parts of Idaho and Nevada. About 16,000 years ago, Lake Bonneville started to shrink as the climate grew warmer and drier. As its waters disappeared, salt deposits were left behind. Though the salt crust is usually dry on the surface today, mud lies just beneath it.

What about the “flats” part of the name? For a stretch of about 12 miles long and 5 miles wide, the Bonneville Salt Flats are almost perfectly level. That makes the site irresistible to car designers, test car drivers, and motorcyclists. They flock there to test their vehicles at high speeds.

To protect the special surface from all that action, a group called Save the Salt repairs any damage. Each spring, it pumps a super-salty water mixture onto the ground. That helps keep the flats bright and crusty!

—Kathy Wilmore