The young shirtless Indian argued testily with Longest Walk leader Vernon Bellecourt in the muggy heat of the Indian encampment in Greenbelt Park yesterday while 200 to 300 other Indians waited patiently to leave the camp.

A faint odor of alcohol lingered in the air from the night before. Park rangers watched warily from a distance. Bellecourt, a strapping man with a commanding voice, ordered the youth to stop arguing. The youth withdrew.

Fatigue, frayed nerves, lack of money and mounting officials pressure to end the Indians' now over-extended encampment combined yesterday to shake the fragile peace and cooperation that have kept the camp intact since July 13.

Though the week of Longest Walk political demonstrations and religious ceremonies ended Friday and the camp was to be officially closed Monday, remnants of the 2,800 Indians and supporters were still stranded in Greenbelt Park late yesterday. The Indians, many of whom walked across portions of the United States to get here, say they have little or no money for the return home.

Battered cars from South Dakota and Oklahoma were lined up waiting to leave. Knapsacks and suitcases were strewn along the camp road. Indians from assorted tribes lolled in small groups, talking quietly.

Officials of the United Methodist Church, the principal private financial backer of the Longest Walk, say they have already distributed at least $76,300 in cash travel grants, including airline tickets for some tribal elders, and are almost $42,000 in debt to various church organizations and individuals who lent money to the effort.

"We've extended this agency as far as it can go," said the Rev. John P. Adams, director of the church's Department of Law, Justice and Community Relations.

Adams said he had diverted $10,000 he had borrowed to remodel his own kitchen to Longest Walk travel costs.

Tuesday night, Adams scraped up another $7,700 from private contributors and yesterday, with two Longest Walk security guards, he hand-carried the cash to the Greenbelt encampment.

Following a formula based on estimated gasoline mileage, distance to home destinations and a daily food allowance, church and Longest Walk leaders processed groups of Indians leaving in cars and buses. The paid bus travelers an average of $90 each and car travelers about $46 each, according to Adams. But scores of Indians remained in the camp late yesterday and the cash fund was reportedly running low.

Park rangers, in coordination with Indian security, began checking outgoing car license tags after reports that occupants of some cars had returned for unauthorized second cash grants.

Meanwhile, National Park Service and Interior Department officials met to discuss ways of speeding the Indians' departure. Pressure to clear the 1,100-acre park in Prince George's County for use by regular campers appeared to be building, according to one source at the meeting, but was tempered by a general agreement to preserve the delicate cooperation achieved by park rangers and Indian leaders so far.