Aleida Van Dyke pulled off her rain pants when it warmed up yesterday, revealing legs as hard as hemp rope. She settled onto a curb, retied her running shoes and bit into a Moonpie cookie.

It was 10 a.m. and long before the end of her walk. But Van Dyke, a 72-year-old hotel inspector, had already gone four or five miles along Route 7 in Loudoun and Fairfax counties. She still had at least 10 miles to go.

Along with about 80 other environmentalists -- including several children -- the Minnesota native is heading to New York from Los Angeles in a 3,200-mile march that started Feb. 1, to draw attention to environmental issues.

"I'm absolutely addicted to walking," Van Dyke said, explaining why she continued walking despite such trials as a blizzard in Arizona, rude drivers in West Virginia and smog along Route 7. "I love walking through the country."

A visit to Washington today through Sunday will mark the beginning of the walk's last leg. The participants plan to visit the Vietnam Veterans Memorial, Rock Creek Park and other sites. Several walkers from the Soviet Union will speak about the environment this morning at Duke Ellington High School for the Arts.

The cross-country trek is called "A Global Walk for a Livable World," and walkers say they have succeeded in more ways than one. They have shared their message with thousands of students along the way. At least one baby has been conceived. One couple got married. And about 40 of those in the group have gone nearly 3,000 miles, a milestone they will reach Monday in College Park.

Wesley Derbyshire, 28, left a job at a recording studio in Manhattan to walk. He said it has changed his values. "We don't need the big house. We don't need the color televisions and two cars," he said.

Several women who had joined a similar walk against nuclear weapons in 1986 planned this one. Liz Walker, 36, said she and other organizers felt that deforestation, acid rain and other issues do not get enough attention. "To me, the crisis is paramount," she said.

The walk took a year to plan. The walkers went from California through Arizona, Texas, Missouri, Indiana and east to Virginia. One man in West Virginia agreed to let them sleep on his property -- until he caught sight of the group's clothing and its caravan of wildly painted buses, said Alison Polly, 20, a college student who dropped out to join the walk.

"We're different from the rest of society, but we're also a microcosm of society," she said. "People think we're hippies, but we're not."

Walker said the group includes students, teachers, artists, a receptionist, a lawyer, a computer programmer and several self-described anarchists. Several people came from other countries.

Numerous people have joined and dropped out since February. Those trooping through Virginia yesterday looked like a cross between medieval troubadours and members of the Sierra Club. Some wore floppy hats and colorful skirts over long johns. Others had expensive outdoor clothing.

Nearly everyone sleeps in small tents and lives out of backpacks, which are carried to each campsite by one of several old school buses. Although organizers had raised about $20,000, each member must pay $11 a day to offset costs.

They cook vegetarian meals out of a trailer towed by a pickup truck. When they want to dance, one of two bands hooks up loudspeakers. Burned-out walkers can ride some days in a special "blister bus."

The trip has had its warts. One woman was disappointed the group was made up mostly of white middle-class activists such as herself. She wanted to address issues of racism during the trip. Another walker said a dispute about whether to allow those without money to join the group has bubbled for months, with no resolution in site.

"What keeps me here is I realize I'm always learning something," said Alison Smooker, 21, an anthropology student at the University of California at Santa Cruz. "It's a real roller coaster."