At 37, Andre Agassi might be ancient for tennis, but he's gunning for rookie of the year in the world of mountain-resort developers. This spring, Agassi, along with wife and fellow Grand Slam champion Steffi Graf, 38, breaks ground on the $350 million, five-star Fairmont Tamarack hotel, at Idaho's Tamarack Resort. It's a risky and aggressive venture—which sounds just right for the man who used to strike baseline winners from impossible angles. Tamarack is no Aspen or Vail; it's a four-year-old upstart resort in hardscrabble central Idaho, more than two hours from the nearest commercial airport, in Boise. From this isolated venue, the Fairmont will have to compete against the upscale private rentals of Idaho's original celebrity ski destination, Sun Valley, a 275-mile drive southeast. Agassi insists the remote location is their ace:"The mountains are beautiful, it's not Hollywood-oriented, and there are never any crowds." With millions tied up in the Fairmont, which is scheduled to open in 2010, the couple can't afford defeat. Meanwhile, Agassi, Graf, and their two kids, Jaz Elle, four, and Jaden Gil, six, are already enjoying mountain life, splitting their time between Idaho and Las Vegas. "My father never even allowed me to go off a diving board as a kid. I had to avoid anything that might have made my career shorter," says Agassi, who started snowboarding last year. "Now I just put on my headphones and cruise."