The House Appropriations Committee, despite a plea that the late Marjorie Merriweather Post's Mar-a-Lago estate was a "cultural endangered species," yesterday recommended that Congress give the Palm Beach palace back to the Post Foundation, together with its $1-million endowment.

The 115-room mansion was given to the nation by the late Mrs. Post as a vacation residence for the President and a rest stop for state visitors on their way to Washington. Neither has ever shown any interest in using the magnificient estate with its 17 acres of prime Palm Beach property. Congress has objected to its maintenance costs.

The National Park Service has said that it would cost the taxpayers about $380,000 a year to open Mar-a-Lago on a limited visitation basis. Another $180,000 for expenses would come from The Post endowment, for a total yearly operating expense of $560,000.

In a report to the committee, Gary Everhardt, director of the Park Service, wrote "Mar-a-Lago is unique, recognized as a finely maintained example of a way of life in a resort atmosphere of the recent past. Its architecture, decoration and landscaping have earned it recognition as nationally significant. The home is an unexcelled example of the way a very wealthy woman provided a colorful, luxurious atmosphere in which the rich and famous of the 1920s-1970s relaxed. It is evidence of a way of life fast disappearing, but the National Park Service can retain the essence of this special portion of American culture indefinitely. This . . . will be even more appreciated in 2026 than it is in 1976."

Mrs. Post's great Forest Hills, Washington, D.C., mansion, Hillwood, was given to the Smithsonian Institution. The Smithsonian gave it back about a year ago, because of the cost of maintaining the estate in compliance with Mrs. Post's complex will.

The Post Foundation which now operates the estate has opened the gardens of Hillwood on a reservation-only basis.

Mar-a-Lago has never been opened to the public and the rich neighboring estate-owners have been concerned about the policing of visitors. If Mar-a-Lago is returned to the Post estate it could, of course, be sold off in lots, demolished, or bought by a group which might be willing to preserve it.