By David Malakoff

Conducting field research on Arizona’s Perry Mesa, a rugged wedge of desert some forty miles north of Phoenix known for its dazzling rock art and ancient ruins perched atop spectacular cliffs, can be challenging. “There are these basalt cobbles and boulders all over the place—it seems like you can’t take a step without tripping over one,” said archaeologist Will Russell. But in some places the stony terrain abruptly gives way to long, linear clearings that have been swept clean. “Suddenly, you’re on this nice smooth path that looks like an abandoned dirt road.”

When Russell first encountered one of those clearings about fifteen years ago, while a student at Arizona State University (ASU), he became intrigued. He learned that archaeologists had documented about a half-dozen of the tracks, which had been purposefully built and were often associated with the remains of masonry dwellings—some with more than 100 rooms—that people had built atop Perry Mesa some 700 years ago. Local ranchers had dubbed the features “racetracks” because they eased the task of moving livestock. “But mostly they were this enigma,” Russell recalled. “Nobody really knew why the tracks had been built or how they’d been used, and no one seemed super interested in figuring it out.”

Russell soon set out to change that, joining other researchers to conduct a years-long effort to document the tracks and probe their purpose. To the team’s surprise, ground and aerial surveys revealed that the tracks were far more common on Perry Mesa and nearby lands than anyone had realized. “It seemed like we found one everywhere we looked,” said Russell, who went on to earn a doctorate from ASU and now works for Arizona’s transportation department. Ultimately, the search increased the number of confirmed and possible racetracks from just a handful to nearly eighty, and they ranged from as short as 200 feet to more than a third of a mile long. And when the researchers mapped the locations of the tracks and estimated their ages, it became clear that in the 1300s Perry Mesa had been the epicenter of an unusual track-building phenomenon. “The racetracks are essentially unique to central Arizona at that time,” Russell said. “Other places don’t have anything like them.”

This is an article excerpt from the Spring 2022 edition of American Archaeology Magazine. Become a member of The Archaeological Conservancy for your complimentary subscription.