Ah, wilderness, where nameless rivers run and the mountains go on forever and sourdoughs and bureaucrats alike wax poetic. . .

Among the 500 people who turned out last night at the Palladin Room of the Shoreham Hotel there were lots of both. And there were government big shots, environmentalists and armchair extollers of natural wonders admiring slides of such Alaska hot spots as Cape Krusenstern and the Romonzanof Mountains, where they will never go, but will forever tell you how much they would like to.

The party was thrown by the Alaska Coalition to celebrate the passage last month of the Alaska lands bill, which will double the size of the national park system and triple the area of protected wilderness. The signing of the bill this morning by President Carter caps a nine-year battle in which slide projectors served as howitzers.

And what a well-dressed army it was, not a grungy Alaska CPO or vapor-barrier boot in sight in the line where Rep. John Anderson, whose hair seemed about as white as the Ruth Glacier, moved past the crudite and the king salmon. "I've never seen the Alaska people so dressed up," said Vicki Dompka, an environmentalist.

Dee Frankforth, a coalition lobbyist headed back to her native Anchorage, where lepers are preferred to environmentalists, sighed.

"This is as close to a wedding as I'll ever get," she said. "I'm apprehensive, but I won't miss summers in D.C."

Sterling Bolima came down from Admiralty Island, where it is hard to move without flushing a bald eagle or bumping your head on a 200-year-old spruce. Of the 500 people in his village, he's the only engineer. He swigged on his Scotch and soda and shouted over the 12-piece orchestra, which was creamily rendering Glenn Miller.

"I've put six years into this bill," Bolima said. "Over the six years, I've spent maybe two in D.C. It's not bad, a month at a time."

Standing by the droopy fronds of the only living plant in the ballroom was Jack Hession, who amazed readers of John McPhee's "Coming Into the Country" by cavalierly leaving McPhee's canoe party one day and striking off alone by kayak for his Anchorage office, 400 miles of wilderness river and bears between him and his paperwork. He said he was glad it was all over too, but expected to be back again to shore up the bill.

Nearby, the Sierra Club president, Edgar Wayburn, said he had hoped for an even stronger bill. "On the third of November I was emphatic that we should get a better bill. But on the fourth I said let's get this one through."

Several congressmen and a couple of other Cabinet colleagues not at all shy about being seen with environmentalists clapped along with the crowd for Interior Secretary Cecil Andrus, who has repeatedly called this "the greatest conservation act in history."

Like many in the administration, Andrus is planning his goodbye to Washington. "My home is sold," he said, but added, "Man, am I glad to be here tonight. Generations yet unborn will have the opportunity to see the world as God created it."

As for Washington, said Ron Andre, the head of the National Congress of Indians and the only man in the crowd with braids, "This is as far from the wilderness as you can get."