Every summer hundreds of District youngsters travel 90 miles from the familiar surroundings of their inner-city neighborhoods to the contrasting environment of the D.C. Recreation Department's Resident Camp at Scotland, Md.

The Resident Camp is located on 217 acres of choice rural land in St. Mary's County, on the shore of the Potomac River near Point Lookout. It has wide open fields and thick, wildlife-filled wooded areas for hiking and athletic activities. The main camping ground resembles a spacious MASH compound, with U.S. Army tents to house campers 9 to 13 years old.

But the 100 youngsters a week who now get the free camping experience are only one-third the number the facility could accommodate when the city purchased it from the Police Boys Club in 1970. In the early '70s, Maryland officials ordered the city to reduce the number because the septic-tank disposal system that serves the camp was inadequate for 300 campers.

"Camping is like a new phase of life for the kids," said Ernest H. Bell, who has been the camp director for 11 years. Bell said the Resident Camp provides youngsters with a chance to experience "good living" in a natural environment away from the high crime and drug-infested neighborhoods that many of them are exposed to in the city.

The 10-week session is divided into two segments, with boys attending for the first half and girls for the second five weeks.

"Before this camp was started, a lot of the kids did not have an opportunity to get out of the confines of their immediate neighborhoods," Bell said as he watched campers and counselors prepare for their morning activities one day recently.

The program has been able to overcome the problem of not having permanent sleeping facilities with the help of the Military District of Washington, which provides the camp with 22 free tents each summer.

"If they did not provide those tents for us, there would not be any place to stay and the camp would not be able to operate," said Samuel LaBeach, associate director of the recreation department.

Katherine Johnson, who supervises the female camping session, said she has seen a gradual equalization of camping privileges for girls since she became assistant director eight years ago.

"When I first started," she said, "the girls only had three-week sessions and the boys had seven weeks, even though we got a better response from the girls than we did from the boys."

Dwight Boston, 10, is a "rookie" camper this summer. Although he said he "expected to see some girls down here," when he came to camp, "It's better than being at the house, . . . .My mother sent me to camp because I was getting on her nerves."

Maria Nicholson, in her sixth summer as a counselor, said she has noticed that the wave of homesickness common in campers' first days fades quickly. "By the end of the week they all want to come back."