Maneuvering his tiny electronic wheelchair like an Indianapolis 500 race car driver, Bong Delrosario, 6, of Baltimore pushed the throttle forward to "full speed" with his elbow and sped across a field where a group of handicapped children had gathered for their "very first ride on a real horse."

His hands too weak to untie the protective harness, Bong cried excitedly, "Hey, somebody help me with these straps, please."

Maria Forlenza, one of the counselors here at Camp Greentop in the Catoctin Mountains, gathered him into her arms and lifted him onto a snow-white mare. The boy was wide-eyed and he howled as the other children cheered him on. "Hey, I'm Superman. I can jump over a barn with this horse," he said.

Last week, the camp, in Frederick County 65 miles north of Washington, was host to 78 children ranging in age from 6 to 13. The children went swimming and horseback riding and some even helped as camp cooks.

Most of the children here suffer from a complex variety of bone, muscle and central nervous system diseases. Some of these diseases are arthrogryposis, a birth disorder that affects joints and connective tissue by contractures of the limbs; cerebral palsy, a central nervous system disorder that often causes paralysis, and osteogenesis imperfecta, known as the brittle-bone disease. The causes of these diseases are varied and often occur before and during birth.

"We try to motivate the children to compete far beyond their own disabilities," says camp director Cisco Nochera. "If they want to go fishing or have archery competitions, we try to arrange the camp to suit their needs."

Two weeks ago, a group of handicapped teen-agers from the Washington-Baltimore area went mountain-climbing here, using special harnesses and protective pads.

Even the younger children went on overnight exploring expeditions, using compasses and maps to find the "camp and fishing sites," Nochera says. The children are encouraged not to depend on counselors and they must assist themselves with their wheelchairs, he said.

Last week, the children held a Halloween party and a "Love Boat" dance complete with a dating service run by several of the children. "Everybody had dates," Nochera said.

On this day, some of the children were gathered around a small cabin to make toy airplanes.

Sharon Brown, 7, her blond hair splattered by blue paint, held up her creation so everyone could see. "Hey, it flies!" she said. But a few seconds later, it went plop. "It landed in the glue," she said.

Scott Kiefer, 11, of Silver Spring, who has spina bifida, shook his head and said: "What a mess. I hope mine wins first prize."

Every two hours, the children are placed on mats. Parts of their bodies are numb and weak from disuse. Here, the children are taught rolling and stretching exercises that help prevent painful skin ulcers, which often occur from sitting in wheelchairs all day.

Lunch hours are fun events here. Once the camp director drove his motorcycle into the camp dining room, giving the children his impression of "The Fonz."

"These kids have what the rest of the world should have--fortitude and courage," said Dick Frye, one of the 60 camp counselors. "Society has a way of putting up social and employment barriers to handicapped people. That's really unfair. Because when you know a handicapped person, the first thing you realize is how wonderfully bright and adaptive and what loving persons they actually are."

Some of the children here call Frye "Papa Smurf." Ten years ago, Frye retired as a Baltimore businessman after a stroke left him paralyzed on the right side. Since his retirement, he has spent his summers at the camp. He says his own disability has given a deeper meaning to his life and a greater understanding of what these children go through.

"That's why we hug these kids a lot and try to give them a better sense of themselves," he says, holding 12-year-old Jill Steckler of Rockville, who has spina bifida.

Many of the counselors themselves are handicapped. Two of them, Victor West, a 28-year-old polio victim, and Arthur (Sunshine) Alston, a 24-year-old cerebral palsy victim, both started coming to the camp as children more than 19 years ago.

"These are loving people," West says. "You don't have to prove yourself. Everyone is loved here."

Alston says, "I guess you could say it's more than a place for some very special kids. It's a place to find yourself."

Camp Greentop is operated every summer with funds from the League for the Handicapped of Baltimore, as it has been for the past 46 years, but the National Park Service owns the land and maintains the cabins and campsites.

The 150-acre camp is actually a slice of the much larger 5,769-acre Catoctin Mountain Park. The cabins there were built by Works Progress Administration workers during the Depression, and for a brief period during World War II, the camp was used as a training base for Marines.