Indian security guards in pigtails and dark glasses stand at the camp entrance here with their CB radio units, checking all visitors. "No Guns. No Drugs, No Alcohol" reads the sign at the entrance.

Beyond the sign along a gently rolling hillside lies the camp - a jumbled assemblage of traditional tepees, modern nylon tents, battered old model cars, and Maryland National Guard vehicles.

It is the encampment of "The Longest Walk" in a section of this park just west of Baltimore - about 700 to 1,000 American Indians who have walked all or portions of a 2,700-mile trek across the country from California to bring prayers and political protests to the nation's capital.

It is a camp of contrasts. Indian children in faded Adidas sneakers skip past ancient Navajo women in traditional dress. A pickup truck with a CB antenna is parked next to a 20-foot tepee. The smell of wood smoke from Indian tents fills the air as Maryland national guardsmen, in the camp at the request of the Indians and at the order of Acting Gov. Blair Lee III, tend modern gas-fired field kitchens to feed the crowds. Bill Means, a Longest Walk coordinator and leader of the American Indian Movement, wears a digital watch set in a beaded wrist band.

The Indians at Patapsco Park are poised for the last leg of the Longest Walk - a march into Washington on Saturday followed by seven days of religious ceremonies, rallies, work-shops and demonstrations.

They say their purpose is two-fold: to display their culture and spiritual life to non-Indian America and to protest legislation in Congress that they say is designed to deprive them of land, mineral, water, fishing and other treaty rights.

Organizers say they expect their numbers to swell to 3,000 for the Saturday march. They expressed concern yesterday that logistical support - field kitchens, water, sanitary facilities, transportation - still have not been obtained in negotiations with federal and local officials for the Indians during their seven-day encampment in the Washington area.

The Indians are scheduled to move out of Patapsco State Park on Friday and go to Greenbelt (National) Park in Prince George's County where the bulk of the participants will be encamped.

A smaller group of 200 or 300 tribal elders and religious leaders is also expected to establish an enclosed "spiritual camp" in West Potomac Park near the London Memorial. Here, with several sacred tepees and an altar containing a perpetually burning fire, the religious leaders will conduct a four-day vigil.

Plans call for the Indians in Greenbelt Park 12 miles away to be brought by bus or other vehicles into the city each day for rallies and demonstrations and return each night to Greenbelt.

Negotiations between Longest Walk organizers and various federal officials including White House representatives over supplies and logistics for Greenbelt Park have bogged down in regulatory red tape.

"We're in a stalemate, a serious stalemate," said Patricia Marks, staff member of the Senate Select Committee on Indian Affairs, which has attempted to intercede for the Indians at both the White House and Interior and Defense Departments.

"It takes 48 hours just to organize the logistics and get them in place, once they've been authorized," said Marks, "and we're running out of time."

The Maryland National Guard will not provide the support it now is giving at Patapsco State Park because the Indians will be in federal, rather than state, jurisdiction when they move to Greenbelt Park on Friday.

"The problem is basically this," said Marks. "The Indians don't have any money, and the federal government are the only people that can supply the large-scale logistics we need for 3,000 people."

Despite the current impasse, the mood of the Longest Walk encampment at Patapsco State Park appears positive, and the leadership repeatedly has stressed the peaceful, religious and nonconfrontational nature of the walk.

Conceived last year by a broad coalition of Indian groups, the Longest Walk has focused not only on its religious purposes but, at a more mundane level, on 11 specific bills in Congress that the Indians say are calculated to abrogate various treaty rights. The legislation, they say, is part of an anti-Indian backlash triggered by recent court victories upholding Indian land claims. They say it also is a continuation of traditional discrimination against Indians and is being pushed by industrial and business interests eager to tap mineral and other resources on Indian lands because of diminishing resources elsewhere.

The Longest Walk started from Sacramento, Calif., last Feb. 11, with several hundred marchers.It moved slowly eastward along U.S. Rte. 50 and Interstate 70, picking up Indian groups along the way.

Some walkers dropped out, but the main group gradually grew in size and is now thought to be 700 to 1,000 with more coming into Patapsco Park each day.

A motley caravan of pickup trucks, vans, and mud-smeared cars from South Dakota, Oklahoma, Wisconsin, California and other states with large Indian populations has accompanied the walkers, providing shelter and relief.

Tod Polanco, a 16-year-old Shoshone youth from California, is one of the few who made the entire walk from Sacramento.

"I guess I went through five or six pairs of shoes," he said yesterday. He had no money for new shoes, but when a town or church donated shoes along the walk route, "I would go through the pile till I found a pair that fit me."

He said the group slept in school buildings, gyms, churches and fair grounds as it traveled, "but we slept out in the snow and rain sometimes."

At the state park here, the Indians are divided into rough geographical and tribal encampments, including the Navajo Nation, the Six Nations Confederacy of the Iroquois and the Lakota Nation, consisting largely of the Oglala Sioux of South Dakota.

While the Longest Walk is a coalition of more than 100 Indians groups and has leaders ranging from militant members of AIM to more moderate tribal council officials, much of the planning for the walk has been done by AIM members.

"We've been at this kind of thing a long, long time," said John Thomas, an AIM member and walk coordinator. "We know the bureaucracy, we know the churches, we know the government."

Russell Means, another AIM leader and walk coordinator, said at a recent press conference that the Indians are coming to Washington in peace and intend no confrontations such as that that led to the takeover of the Bureau of Indian Affairs building here in 1972.

He said relations between Indian organizers and government officials are "100 percent better" for the Longest Walk than for the 1972 Trail of Broken Treaties protest action that led to the BIA takeover.

"Every door was shut on us in 1972," he said. "This time, every door is wide open."

Moments earlier at the press conference, Means said, "We know the futility of continually approaching the colonial monster in Washington, D.C." to gain rights for Indians. "We live in the belly of the monster. We keep losing our land. We keep losing our rights . . . But we approach Washington, D.C., once again in hopes that the integrity and honesty of the founding fathers of this country will somehow come to the surface."