"The Problem," said Virginia game warden Barry Lape as Arlington detectives, patrolmen and motorcycle officers rushed up and down Lee Highway and a helicopter circled overhead, "is that a bear is not something they see every day."

This black bear, though, the police saw frequently yesterday. And sure it disappeared into the Spout Run woods after a chase and search that began at about 11 a.m. and ended at 3:30 p.m., they may see it again today or Wednesday.

The bear first was spotted by an officer driving down Lee Highway near Uhle Street. His first words, according to another officer, were, "That's a BEAR! I hope when I call this in they don't think I'm crazy."

The official response was enthusiastic if not effecitve. No one wanted to hurt the bear so guns, through carried, were not to be used. It also is very difficult to handcuff a bear.

Officers patrolled the highway and calls had gone out to the state and Fairfax game wardens. Arlington dog wardens were not ready for bear.

The bear was fairly cornered in a small triangle of woods behind the Marriott Key Bridge Hotel, and the woods was ringed by men leaping up and down and yelling "Whoo, Whoo" as the bear neared the edge of the cordon.

The bear - "I belive they get confused," said Lape of bears in general - bolted past three men, across Lee Highway, up a bank of poison ivy and raced off down a bicycle trail.

A group of spectators gathered at a gas station cheered the escape and a small boy who earlier had gluded a reporter to the bear leaped for joy. A sweat-soaked police officer carrying a shotgun climbed through the poison ivy after the bear.

A service station attendant described the bear as "a little cup about this high," holding his hand at thigh level.

An officer who had just seen the bear go by at close range said the bear "looked thin but pretty big."

The bear by now was dashing through woods on the south side of Lee Highway and occasionally through an apartment house backyard.

An elderly man in a bathrobe leaned out a window and said. "He just went by. Looked about half-grown and running real fast."

A woman ran out of another apartment and told a motorcycle officer, "I saw him 3 minutes ago and he was really moving."

Lape and the Fairfax County game warden J.H. Smith, who had the only tranquilizer gun, were attempting to work close enough to the bear for a shot with the sleep-inducing dart.

A loudspeaker on a police cruiser blared. "Will all civilians please leave the woods?" Individual police officers' radios yammered out the lastest sightings and the helicopter circled overhead.

A sighting brought shouts of "There he is." and a stampede of small boys, television cameramen, newsmen and detectives lugging .38s and handcuffs. Also a panicky escape of the bear, who very quickly was no longer where he had just been been.

"We never got close enough for a shot," said Lape later. "It was heavy underbush and we didn't want to shoot while it was running. The tranquilizer could kill him if it hit him in the wrong spot and we didn't want to hurt him."

The bear was reported almost simultaneously on both sides of Lee Highway, the sort of thing that happens as a search gets older. Then the bear did break across the highway and into the woods along Spout Run.

"When he did that, that was it," said Lape. "Bears are totally unpredictable when they get in a new area. He's very tried and he's going to get in a thicket and rest."

The bear, a young one weighing about 150 pounds, is likely to show up again in a few days, Lape said. "Today the police tried to chase him - exactly the wrong trying to do, but that's human nature. No comment on the helicopter. We'd like them to sit just watch him . . . until we could get a clear shot at him."

If caught, the bear will get a rest, a tag and a trip back to the Shenandoah National Park, from whence he probably came, Lape said.

The Arlington Police Department's news tape recording described the sighting of "a very frightened bear club" and concluded that "it appears the club has given its pursuers the slip."

The Arlington police dispatcher, just before the search ended, said the bear was believed heading for the Potomac River "because the bear had its tongue handing out and looked thirsty."