A white-tailed deer bounds across a paved road in two effortless strides, landing in a sea of green forest. Nearby, a chipmunk races through tall grass past a shimmering stream that slips quietly across a bottom of smooth stones.

Prince William Forest Park, larger than Arlington with 18,500 acres of lush forest, 35 miles of trails, campgrounds and rustic log cabins, is a refuge in the wild just minutes from the homes of Northern Virginians.

"It provides a chance to renew the spirit, to get out to see the birds, the deer running and the beavers," park ranger Riley Hoggard said of the park, which runs along the southeastern edge of Prince William County. "It smells good here, and the forest is so green it almost looks blue."

Each year, more than 400,000 people visit the forest, which is maintained by the National Park Service for the U.S. Department of the Interior.

Camping is allowed in the southeastern, central and northwestern areas of the park. There is also a backpacking and camping area adjacent to the Quantico Marine base, which borders the forest to the south and the west.

Jim and Jean Tyson of Charlotte, N.C., recently came back to the park to visit the site where they camped 20 years ago. "We stayed here four days and nights, and I remember as we left, three wild turkeys ran across the road," Jim Tyson, 61, said. According to Jean Tyson, 59, "the peace and tranquillity is what we remember."

Less than a mile away, Laurie Turner, 33, and her daughter D.D., 7, were trying to keep cool under a blanket fastened to the side of a small camper to keep out the sun. They, too, enjoyed the solitude of the forest, but for a different reason. Turner said she and her husband Johnnie, a construction worker, were living there on an almost permanent basis because they could not afford the metropolitan area's housing. Housing "was bleeding us dry," Laurie Turner said.

Hoggard estimated that 10 percent of the campers in the park are what the rangers call "homesteaders." "We get a lot of people that just can't afford the housing."

Though people are welcome to stay in the forest for 14 nights per year, park officials do not encourage homesteading because it crowds out tourists who want to stay a short time, Hoggard said.

"It's great to let the kids run loose for a while," said Melody Ayers of Stafford County as her children -- Jason, 7, Jesse, 6, and Crystal, 5 -- romped outside their brown tent. "They can get dirty and cruddy and no one cares," said Ayers, whose family was staying at the park for a couple of days. Jason said he liked the forest "because you can play with turtles and find snakes."

Snakes are the wildlife most frequently asked about, said Ranger Barb Maynes, who works in the park's log cabin nature center. Besides snakes, visitors can find red foxes, raccoons, red-tailed hawks and owls indigenous to this Piedmont forest of oaks, red cedar and Virginia pine.

"This is a newt; it's an amphibian," said Brent Syphax, 10, holding out the green, inch-long creature. Brent was one of about 100 metropolitan area children, ages 7 to 10, sent for two weeks of summer camp in a program sponsored by Family Child Services.

"It's such a break from the problems of the city," said Stacey Mitchell, an assistant director at Camp Pleasant, which was being housed in cabins built by President Franklin D. Roosevelt's Civilian Conservation Corps. Eight-year-old Jackie Barnes would agree. She sat with Mitchell playing a modern version of patty-cake as her friends received a lesson in canoeing at a small lake not far away. "Boogie night, ohhh-ohhh. Got to keep on dancing. Keep on dancing," Mitchell and Barnes sang.

Daymin Gale, 9, said he liked "mostly everything" about the forest: "Where I lived . . . we couldn't go outside."

Not everyone was pleased with the idea of being close to nature.

"We need air conditioners," said Matthew Russell, 12, of Woodbridge, who was with about 80 youths, ages 6 to 12, in an overnight stay at the forest sponsored by the Prince William County Park Authority. "I wish we had a condo," echoed Brittany Craig, 11, of Dumfries.

The youth from the suburbs joked about changing the forest. But for Hoggard, who also serves as the park's resource manager, the pressures from the suburban corridor sprouting on the park's northern border pose a real threat to the vitality of the forest.

"The trees, the soils -- I have to make sure we mitigate impacts," Hoggard said. Park officials have been concerned about protecting the park's boundaries. Campers hiking on trails do not necessarily want to see a housing development, Hoggard said. Erosion, noise and pesticides can directly affect the forest.

Rangers routinely attend meetings of the Prince William Board of County Supervisors to keep informed about developments that might affect the forest. Hoggard said that sometimes the federal park is at odds with the county when the locality wants "a few acres to build a soccer field or a baseball field." The park is one of six sites under consideration for a 600-acre airport, park officials said.

The park's southern neighbor, the Quantico Marine base, occasionally presents a noise problem. For example, Hoggard said, the sound of machine gun fire or helicopters sometimes breaks the silence of the forest.

When the park's 15 rangers are not fighting man-made problems, they are dealing with nature's blights. On a recent hot and humid afternoon, ranger Beth Waldow was checking trees to see if the gypsy moth, which can devastate woodland forests, had appeared. Hoggard said rangers are worried because oak leaves, which are prevalent in the park, are a known delicacy for gypsy moths.

Hoggard speaks about the park with a passion. It was acquired by the federal government in 1933, and became part of the national park system in 1940. The mandate of the Park Service is to provide for the public and at the same time protect a delicate ecosystem, he said. About 4,000 acres of the forest that is marked by rolling hills is unpenetrated by man, according to Hoggard.

"As the Washington area grows, this place will become more important," he said.

Acting Park Superintendent Jim Fugate called the forest "a little piece of paradise in the metro area . . . a little piece of heaven."

Or as camper Yvonne Clemens, 39, of Dale City put it: "You can come out here for two or three days and feel like you've had two weeks' vacation."