The Fun Fly Rally in California’s Central Valley is featured in a new report from Wired. Organized by officials with the Seagull Flying Club, the rally is part air race, part airborne scavenger hunt, in which  pilots fly 166 miles from Tracy to Los Banos without modern navigational aids.

The report notes:

“It’s strictly old-school technology where pilots fly by visual flight rules and rely on clues to find checkpoints. The goal is to accurately predict how much time they’ll need to complete the course and how much fuel they’ll burn doing it.”

Read a full account of the rally here.