"Tregaron should be preserved in as natural a state as possible. It provides essential environmental controls in the area, retaining ground water, filtering and cooling air and preventing further flooding of Macomb Street," - from a flier circulated by a Cleveland Park group called "Citizens for City Living."

No sooner was the tentative sale of Tregaron to a developer announced late last year than powerful neighborhood groups were meeting, voting and circuating their declarations in an effort to halt or a least control any development.

Tregaron is located at the southern end of Cleveland Park, the close-in northwest area that has become one of Wahington's most desirable, lively and upper-middle income neighborhoods.

The World War I-vintage houses are packed close together on one-fifth acre lots, now sell for $185,000 and up. The area is filled with lawyers, government officials, journalists and other professionals, yound and old, who have a strong, almost village-like community sense.

Wisconsin and Connecticut avenues, which form its western and eastern boundaries, provide a variety of shops and services that residents can walk to.

"Cleveland Park is a very caring community," said Kay McGrath, a resident who heads Citizens for City Living, Inc., an area citizens group. "People are very concerned with holding onto values that are perhaps not (viewed as being) as precious any more - such as a mixture in the neighborhood that gives it vitality. . . It doesn't have any pretension about itself. It isn't always fancying itself up."

Vice President Mondale used to live there, and just after his election he was photographed on the street in his jeans raking leaves - that's the way many people in the area like to think of themselves. Casual. Human.

So it was natural that such a neighborhood should grow affectionate about the great old Tregaron estate and about the International School located there. That this green space should be taken away and filled with more housing creating more traffic was unthinkable.

"I do hope the school has a chance," said McGrath. "They've been a very good neighbor."

Another neighbor, Leo Goodman, has lived for more than 20 years in the neighborhood with a view of Tregaron from his back yard. He remembers that in the 1950s Joseph E. Davies, Tregaron's owner, used to meander down to the back fence to talk with him.

"Davies was quite a human being and quite warm to the human use of the estate, and apparently had some forebodings about what might happen to it," said Goodman. "He said, 'Feel absolutely assured it's not going to be a development. It's going to be either a home for the Vice President or a school of international affairs. I've seen to that'."

But he hadn't.