Alaska's back country can be shrine or haven for reclusive men like John Weymouth, loners seeking escape in the icy expanses.

Weymouth did not say what he was looking for last week when he stepped onto the frozen Bering Strait and walked across the International Date Line into a land where it is always tomorrow, into the Soviet Union. And nobody knows what he found.

Weymouth left San Francisco last fall to travel alone across Alaska's bleak western bush, first boating down the Yukon River, then hiking across the barren tundra. Villagers who met him along the way began calling him The Wanderer. They said he was ill-prepared for the harsh winter and seemed aimless in his quest.

His travels brought him April 2 to the village of Diomede on Little Diomede Island, a speck of turf in the Bering Sea between Alaska's Seward Peninsula and the tip of Siberia. It is separated from Big Diomede -- whose only inhabitants are Soviet troops -- by 2 1/2 miles of ocean that is frozen solid well into May.

Three villagers tried to stop Weymouth when he set out that afternoon, catching up with him at the dateline on their snowmobiles. "He told them to mind their own business," said village public safety officer Thomas Menadelook. "He just kept going . . . .

"I called the state troopers in Nome and asked them what I should do," Menadelook said. "They said, 'Just let him go. There's no law against walking across the line.' But they said, 'Don't go after him.' " The date line, about a mile out, is not marked, but villagers said they can sense when they're approaching it -- and they never cross it.

Neither U.S. nor Soviet authorities have confirmed that Weymouth reached the big island. State Department officials in Washington, D.C., said they have made official inquiries into Weymouth's whereabouts. A Soviet consulate spokesman in San Francisco said the matter is "not part of our duties here."

In the San Francisco Chronicle today, Weymouth's uncle, columnist Herb Caen, described him as "a big, strong, blond guy, a loner with a heart of gold . . . . Wherever you are, Johnny, good luck, keep warm, and come home."

In a telephone interview from her home in San Francisco, Caen's sister, Estelle Barrett, said her son prefers anonymity. "He seemed to like wandering, living on the street," she said. "He had no real friends, never really did."

She described a bright child who attended three private boarding schools and afterward let his life collapse in indecision. He abandoned City College of San Francisco and the University of California-Santa Barbara for Los Angeles where he "did odd jobs -- washing dishes or cooking hamburgers," Barrett said. "Then things began falling apart. He just started living on the street. He would always keep in touch, usually call or write. He said he liked being free, no address, no one telling him what to do."

Weymouth's wanderlust took him through the Pacific Northwest and, early last year, into Alaska. He survived on odd jobs in Anchorage and Fairbanks, then headed for the bush. In September, he embarked in a leaky fiberglass boat that failed him half way down the Yukon River.

After staying for a while in the river village of Galena, 325 miles northwest of Anchorage, Weymouth tried walking 100 miles west to the coast. Villagers reported finding him five days later in a blizzard, his feet frostbitten.

With their help, he recovered and took more odd jobs to earn enough money to hop a charter flight to Nome. From there, he flew to Little Diomede.

About 5:30 p.m. on April 2, villagers watched as Weymouth crossed the date line. The next evening, according to Sgt. Andrew Milligrock of the Army National Guard Eskimo Scout Battalion on Little Diomede, islanders saw and heard the largest display of weapons fire and explosions they could recall seeing from Big Diomede. Barrett said she talked to Weymouth earlier this year by telephone from Galena.

"He was so excited," Barrett said. "When I talked to him, I said jokingly, 'John, if you keep going, you'll get to Russia.' I had toured there six months ago, and we'd talked briefly about it. Whether that put the idea in his head, I don't know.