BUTLER TWP— If two legs aren't available for skiing, try one.

If that doesn't work, learn how to ski sitting down.

That's what Charles Rock, 61, of Butler intends to do as one of more than 400 disabled veterans attending the 23rd National Disabled Veterans Winter Sports Clinic from March 29 through April 3 in Snowmass Village, Colo.

While serving in Vietnam in 1970-71, Rock was hit by friendly fire and wound up having his right leg amputated below the knee. He also suffered nerve damage in his right hand and arm.

"I got into skiing in 1972 while at Valley Forge Hospital,"Rock said. "I learned how to three-track ski and took part in the first National Veterans Ski Championships while I was there."

Three-track skiing is done on one leg. Skiers use one regular alpine ski and adaptive equipment called outriggers, which are forearm crutches with ski tips attached.

Rock said he got started at the urging of Roger Clark, a friend who is an amputee.

"It's good exercise,"Rock said. "Once I started doing it, I was hooked."

A 1967 Butler graduate, Rock competed in gymnastics and cross country in high school. He was a member of the Paul Uram-coached gymnastics squad that never lost a dual meet. Rock finished second in the state on the side horse his senior year.

"The balance I developed in gymnastics helped a great deal in getting back to walking again,"said Rock, who uses a prosthesis and walks with a cane.

Being a high school athlete also fueled his competitive fire when he began skiing competitively in the three-track division, placing third in the slalom at the National Veterans Ski Championships in Mount Hood, Ore., in 1980.

After 30 years of three-track skiing, however, Rock's leg began to give out.

"It's a lot of pressure built up on one leg over that many years," he said. "About four years ago, I had to give it up."

He's missed it ever since.

Within the past year, Rock learned about monoskis, which consist of a fiberglass shell mounted on one ski. The skier uses short outriggers to steer.

Monoskiing is geared toward users with good upper-body stability.

Rock has been working out at the Aebersold Recreation Center at Slippery Rock University, where he's improving his upper body strength.

"Monoskiing is designed for people in wheelchairs who always use their upper body," he said. "I want to be as strong as possible that way.

"I've had a longtime passion for skiing. If sit-down skiing will get me back on the slopes, I'll go for it."

Rock applied for the National Veterans Winter Sports Clinic in September and was accepted in November. His reason for applying was to learn how to monoski.

He soon will be receive a monoski from the Veterans Administration.

"What I love about this clinic is it's designed to get disabled veterans to ski one way or another,"Rock said.

An estimated 200 certified ski instructors for the disabled will work the clinic. Several current and former members of the U.S. Disabled Ski Team serve as instructors as well.

Besides the skiing, the clinic offers instruction in sports such as snowmobiling, scuba diving, skating, sled hockey, curling and cross country skiing.

Rock plans to try curling and sled hockey while he's in Colorado.

"I've heard so much about this clinic," he said. "People from the Secret Service come in and give a clinic on how to defend yourself. I'm looking forward to this trip.

"It's not the end of the world if you become disabled. It's just a different way of getting around."