Piscataway Indians, whose ancestors inhabited most of Maryland and the District 1,500 years ago, are accusing the National Park Service of denying them their constitutional right of religious freedom by not allowing free access to an Indian burial site in Piscataway Park.

The Indians are objecting to the National Park Service's proposed general management plan for Piscataway Park, a seven-mile strip of land along the Potomac River, because it does not provide for an access road to their grounds.

Congress voted in 1961 to preserve the land, which is opposite Mount Vernon, as it was in George Washington's time. Little has been done to it since 1961. The park service wants to put in trails, picnic areas, and a visitors' center some time during the next 15 to 20 years. The service also wants to build a marina at nearby Fort Washington.

Speaking at a hearing conducted by park service planners last Thursday at the Knights of Columbus hall in Accokeek, Michael Smith of Washington said he felt "my right to religion is being threatened by the National Park Service."

"This country has been built on the basis of religious freedom," said another speaker of Indian descent, Daniel Fecko of Crofton. "Denying access to the land is like barring entrance to a church."

A road to the site would have to cross property owned by a group called the Moyaone Association, homeowners who live on the land adjoining the park.

Indians currently must ask the park service in writing--at least 48 hours in advance--for permission to use the burial site for religious festivals or other gatherings. A park service official said the written permission ruling applies to "anyone wanting to use federal property for any First Amendment activity or special event such as a festival . . . ."

Belva Jensen, a retired school teacher who is part of the Moyaone group, objected to the Indians' objections, saying, "The park was created to preserve George Washington's view, not the Piscataway Indians' sweat lodges."

Cynthia Eaglebear, a Piscataway who lives in Washington, rebutted: "Well, that village that was there 1,500 years ago didn't have Mount Vernon across the river."

Gaines Hopkins, an Accokeek resident, was one of those who spoke on behalf of the Indians: "The historical treatment of Indians in this country is deplorable. Let's not keep making the same mistakes our anscestors did; let's not perpetuate this."

About 150 persons attended the hearing, held to gather public opinion on the plan. The public comment period ends June 6.

Some at the hearing spoke of their concern over park service plans to develop a marina at Fort Washington, and said they wanted to see restoration of the historic main house at the former Marshall Hall amusement park, which is included in the Piscataway Park property.