MEDFORD, Ore. -- An unexpected surge in salmon returns, particularly in the Columbia Basin, is ramping up sales of Oregon's signature welded aluminum boats.

Swelling demand is being felt most strongly in the area surrounding Medford, the southern Oregon community that is the capital of Oregon's aluminum boat-building industry.

"Five years ago, we were really struggling," said Trey Carskadon, marketing director for Alumaweld Boats Inc., an industry leader. "Now, we're all grappling with how to meet demand."

The main challenge? Finding -- and holding onto -- enough skilled labor. The solution? Training.

Some companies, including Alumaweld in Eagle Point -- 12 miles north of Medford -- and North River Jet Boats in Roseburg, are teaming up with community colleges to offer classes in welding and boat-building.

About a dozen companies in Oregon manufacture the rugged boats, producing shallow-draft hulls that can be equipped with inboard jet pump engines or outboard propeller engines as well as drift boats powered by oars or a small motor.

The boats became popular among guides because their heavy-gauge aluminum and welded seams make them virtually indestructible, able to handle the worst that Oregon rivers can dish out.

Bob Toman, a Clackamas fishing guide, decided to switch to heavy-duty aluminum in the mid-1970s after he saw the remains of a wooden jet boat on a rock in the Rattlesnake Rapids, 2.6 miles up the Deschutes River.

"All that was left was two 50-horsepower motors and the transom," he said. "That really gets your attention."

Forest Foxworthy of Oregon City, who guides fishing clients on the Deschutes, said "Aluminum boats are for people who don't like poking holes in the hull. Fiberglass can't handle the everyday pounding and abuse these boats get."

Heavy-duty aluminum power boats became increasingly popular with other boaters, first fishermen impressed by their durability and low maintenance and now a growing number of water skiers and wake boarders.

Alumaweld was founded in 1971 by Willie Illingworth, an outdoor adventurer, pioneer and legend in the world of aluminum fishing boats. In the same way that many of Portland's high-tech business leaders got their start at Tektronix, many of the owners and managers of other Oregon aluminum boat-building businesses are Alumaweld alumni.

Illingworth sold Alumaweld to his partner and after a five-year noncompete clause expired, started Willie Boats Inc. to return to making aluminum drift boats and power boats.

Jammie Dorsey started out at Alumaweld and now owns Fish-Rite Inc., across Justice Road from Willie Boats. Now with 26 employees, he plans to increase production from 350 boats last year to 550 boats in 2006.

Brian Brush, a relative newcomer to Oregon's boat-building industry, owns North River Boats in Roseburg. The company produced 41 boats in 1997, built 920 last year and is on track to produce 1,400 this year, he said.

Brush said clients are willing to wait nine months for a custom-built North River boat.

"It's unbelievable right now," he said. "The industry is good for everybody at this point."

Boat manufacturers say 70 percent of the aluminum boats sold in Oregon are used for fishing, and they attribute rising demand mainly to rising salmon numbers.

More than 416,000 spring chinook crossed the Bonneville Dam in 2000, a record high in the dam's 66-year life and more than 40 times the record low of 10,200 fish in 1996.

State fish and wildlife officials in 2001 opened the Columbia River for salmon fishing from January to April for the first time since 1997.

Statewide fishing permit sales have jumped. Anglers bought 210,010 combined salmon, steelhead and sturgeon angling tags in 2003, up 17 percent from 180,172 in 2000.

"We refer to it as salmon fever," Alumaweld's Carskadon said. "The rise in salmon numbers has really been a catalyst for increased fishing throughout the West."

Another factor fueling high demand is low interest rates, which ease the pain of monthly payments on boats that can easily top $35,000. "Fishing is driving it, but low interest rates are sustaining it," Brush said.

Responding to the heightened demand, Oregon's two largest aluminum boat builders have started training programs.

In June, North River Boats landed a $500,000 grant from Douglas County and Oregon, money it will use to put people through a 90-day training program. North River plans to train 128 new workers over the next four years.

Alumaweld will spend about $300,000 training workers over the next three years, company president Doug Rein said. The company is buying a former timber mill eight miles away and converting it to a boat-building plant. It plans to add 30 workers to its staff of 90.

"If we don't spend the money, we won't have an experienced crew," Rein said. "It takes extensive training and a large investment to get the quality of worker we need."

One advantage of being in the Medford area is the ample pool of workers, many of them former employees of closed timber mills.

Ted Davis, a boat assembler at Fish-Rite, is one of those. He was a millwright until the plywood mill that employed him closed in 1989.

"The mill jobs are gone, but now this industry has come to the front," said Davis, who in two days can transform a stack of precut aluminum into an assembled 20-foot boat ready for welding.

But the area also has a downside on the labor front. The industry concentration there can tempt competitors to lure away each other's away workers. Davis, for one, received a better wage four months ago when he left a boat builder where he had worked for 10 years.

Dennis Walton, the Eugene branch manager for Pacific Metal Co., supplies aluminum to many of the boat builders. He sees the intense competition for workers: "The big guys have training programs, and the little guys steal from them."