Washington artists and arts organizations are usually a reclusive lot. Like a band of grizzled prospectors, they work their claims privately, hoping that one day they'll strike their own lode. But Saturday night they came together, turning the Pension Building into a saloon scene from the Gold Rush, in a celebration of unity called Winterfest '81.

"Hey," shouted a Washington painter to a colleague. "I haven't seen you since your show a year ago. You look a little more prosperous these days." Nearby, a local choreographer and a director was exchanging quips about some project long past. "You're the only person I know who can put on a show unannounced and have a thousand people show up," one yelled over the din.

Officially, the evening was a benefit for the D.C. Foundation for Creative Space (in the old Lansburgh's building), The Washington Review and The Unicorn Times. Unofficially, Winterfest '81 was a wild bash, an orgy of togetherness in which artists, actors, musicians, writers, dancers and organization officials gathered to proclaim themselves a "community."

Framed by the gigantic, spotlighted columns of the grand old building, the 1,200 or so participants, dressed in everything from black tie to black tights, mingled, danced and feasted from huge tables piled high with roast beef and seafood. All the while, music -- jazz, rockability, reggae and new wave -- blasted nonstop from a stage at one end of the room. Mulitcolored balloons floated above the tables, a fountain in the middle of the floor danced to the music and various members of the crowd exercised their creavitiy at a quickie photo booth, assuming contorted positions for the camera while a smoke machine wrapped them in fog.

"This is what the arts community has been needing, a focal point," said Livingston Biddle, chairman of the National Endowment for the Arts. As he spoke, a young couple tangoed gracefully near the foundation in defiance of the raucous rock music. "This event," he mused, "is vibrant, alive. I'm thoroughly enjoying myself."

Phil Ogilvie, executive director of the D.C. Foundation, noted, "Winterfest has a dual purpose -- fund-raising and, more importantly, awareness. We are trying to get the artists to meet, work together and exchange ideas." Millie Bautista, the Mayor's adviser for cultural affairs, agreed. "D.C. has been artistically fragmented," she said. "This event and the Foundation are a new lease on life for the arts and also a learning process for the artists."

The learning process at Winterfest seemed to be as much a matter of acquaintanceship as anything else. People resembling characters from the "Rocky Horror Picture Show" traded clams and conversation with gray-haired administrator types. D.C. City Council members mixed with bearded musicians.Georgiane Okes, formerly a dancer with Pilobolus who still lives in New York, said, "I like the feeling here. I'm thinking about moving to Washington because there's an active arts scene but without the pressure of New York."

Oh, oh, oh, oh, oh, oh ---- aaaaaaaaaah," a woman exclaimed as the African Heritage Dancers and Drummers took the stage. Her shriek prompted a spontaneous outburst from the crowd, and soon everyone was hooting and clapping to the infectious rhythms. "Don't stop, don't stop," a young man in a zoot suit chanted to the beat.

Elliot Ryan, publisher of the Unicorn Times and chairman of Winterfest '81, was ebullient. "The is wonderful. It is just what we wanted," he said. "Look at all the segments we have here tonight -- federal, city and neighborhood groups are represented. They have all been working in their own niches and here they are talking to each other. I hope we can make this an annual affair."

And from local concert promoter Mike Schreibman: "I think Winterfest will bring attention to what people are trying to accomplish." Then, giving up his attempt to be serious while wrestling with a roast beef sandwich, he added, "And besides, it's a great party."