Updated

A wildfire raged down the Columbia River Gorge (search) and burned into this small tourist town Tuesday, forcing scores of people from their homes and closing a 47-mile stretch of Interstate 84.

The fire blazed through a former bed and breakfast on the outskirts of town, destroyed at least one home, and threatened many others.

Alarm mounted as the fire, which began in dry brush beside the interstate, approached the town, billowing smoke and creeping up steep gorge walls. Residents affixed sprinklers to their roofs to ward off flames.

Cascade Locks (search), population 1,100, is nestled between the Columbia and sheer cliffs rising hundreds of feet above the river where it cuts through the Cascade range about 40 miles east of Portland.

Resident Marty Pearson's face was streaked with ash as he returned in his pickup truck from helping a friend place sprinklers and clear a fire break. His wife, seven months pregnant, had left town earlier, but Pearson said he would stay to watch over their house.

"I was going to put a new roof on next summer," he said. "If my house burns down now, I'll just have to build a new house altogether."

Two helicopters dipping water from the river and three aerial tankers bombarded the fire with water and retardant to keep the blaze back.

In an effort to get more water to the flames, fire officials diverted a source of non-potable water into the city pipes, and warned residents to boil water before drinking it.

By late afternoon, the Red Cross (search) said about 46 evacuees had made it across the Columbia River to a temporary shelter in Stevenson, Washington.

Another 35 people and their pets had gathered in the gymnasium of Cascade Locks School, said principal Chris Daniels.

The fire may have been started by a power line problem, fire spokesman Jamie Karn said.

Union Pacific Railroad stopped trains along the southern bank of the river because some railroad ties were burning, Nichols said.

The fire caused serious traffic tie-ups as far away as Portland. Cars leaving the city were being rerouted along a two-lane, windy road on the Washington state border, and trucks were being detoured over Mount Hood.

"We've got fire on both sides of the highway and we've got zero visibility with the smoke," Oregon State Police Lt. Dale Rutledge said. "That's a very dangerous situation."