Tarsorial Splendor

) They look like a cross between a dime-store thong and a ripped-up, stripped- down running shoe. Once the uncelebrated darling of Western college students, they are the coolest thing under your feet since Air Jordans and can cost nearly as much.

Sports sandals, this summer's must-have shoe, are now standard equipment for hikers, mountain climbers and even some skydivers. Like the fanny-pack and bike-shorts crazes of the 1980s, they had their origins in the great outdoors. The footwear was originally designed eight years ago by Mark Thatcher, a Colorado river outfitter who found athletic shoes too slippery and spongelike for white-water rafting trips.

His comfortable, quick-drying innovation is fitted with a variable web of beltings, tethers and buckles that snugly grip the toes and the ankle while keeping the foot from sliding back and forth. A tough rubber sole and a high arch take the off-road punishment expected by hikers and mountain climbers; hot colors and a high-tech look are now attracting buyers who want to wear what the rugged, back-to-nature types swear by. "They're all I wear when it's warm," says Dale Covington, who works at the Trailhead, a Missoula, Mont., outfitter, and owns two pairs. "When it cools off, I wear them with socks."

After several years of modest sales, limited almost exclusively to the Western mountain states, the sports-sandal fad has spread to both coasts. The most popular line is known as Teva, made by Deckers Corp. of Santa Barbara, Calif.; they come in 30 different styles and retail for anywhere from $35 to $80. Peter Link, Deckers' vice president for marketing and sales, predicts that revenues from the sandal will double this year to $12 million and double again next year. Says Link: "We want to be the airy alternative to athletic shoes." Clearly, a goal worth striding for.