For a teenager obsessed with rock climbing, the flat scrublands of East Texas were an infuriating place for Ty Foose to come of age. Longing to conquer 300-foot cliffs, he made do with shimmying up the cut-stone face of the Waco (Tex.) courthouse.

Ten years later, the 27-year-old is hoping to make the world more climber-friendly—especially for those in topographically challenged locales. His $500,000 company, Monolothic Sculptures Inc., crafts "interactive artworks"—high-tech mini-mountains used for indoor rock climbing. Just nine months old, the 10-employee Denver firm has already custom-built climbing walls and boulders for outdoor retailers North Face and Recreational Equipment Inc., as well as the University of North Carolina.

As high as 50 feet, Monolithic's structures are remarkably accurate imitations of real-life climbs. Want to clamber up the granite face of a cliff in the Adirondacks or ascend warm Utah sandstone? Using a patented process that treats foam with liquid concrete, Foose and partner Dan Christensen sculpt and paint it into any form they choose, an advantage over competitors' one-sided plywood or fiberglass structures.

It hasn't been an easy ascent. Upon dropping out of Wichita State University after one semester, Foose spent the next eight years as a vagabond climber, trying to make a living from the gear he invented for the growing indoor-climbing industry. He failed. "I knew absolutely nothing about business," says Foose, who recently took an entrepreneurship class at the local chamber of commerce. Armed with new finance and planning skills, Foose is expecting revenues to push $750,000 in 2000. Monolithic is also sweeping into a wave of new business: building public playgrounds. "I wanted to do playground stuff ever since I started climbing," says Foose. Sweet revenge for a vertical man cursed with a horizontal childhood.

By DENNIS BERMAN