GRANTS PASS — Federal fisheries agencies recommended Wednesday that four hydroelectric dams owned by PacifiCorp on the Klamath River be equipped with fish ladders and turbine screens as a condition of getting a new operating license, in order to help struggling salmon on their spawning runs.

If the proposal from the U.S. Fish and Wildlife Service and NOAA Fisheries is adopted by the Federal Energy Regulatory Commission, it would restore access for salmon, steelhead, and lamprey to more than 300 miles of river for the first time since the early 1900s.

Fish ladders to help adult salmon over dams and screens to keep young salmon out of turbines won’t solve all the problems caused by the Klamath Hydroelectric Project, the agencies said. But they hope ongoing settlement talks between PacifiCorp and interest groups could find better remedies, and they urged FERC to evaluate alternatives that include removing the dams.

The 327-page document comes as pressure is growing for the federal government to resolve bitter battles over sharing scarce water between farms and fish in the Klamath Basin, which was once the third-largest salmon producer on the West Coast.

Farmers and fishermen have suffered tens of millions of dollars in lost crops and catches, and Indian tribes have lost access to salmon that are an important part of their culture as well as their diet.

After the third straight year of dangerously low returns of fall chinook salmon to the Klamath, the Pacific Fishery Management Council will decide next week whether to shut down sport and commercial salmon fishing on 700 miles of the West Coast off Oregon and California.

Steve Thompson, head of the California-Nevada office of Fish and Wildlife in Sacramento, Calif., said dam improvements would be an important step in a larger effort to resolve environmental problems in the Klamath Basin.

“I am increasingly encouraged that the people of the Klamath Basin — farmers, tribes and fishermen alike — have joined together to see if they can make that happen,’’ Thompson said in a statement.

Phil Detrich, Klamath issues coordinator for Fish and Wildlife, said habitat restoration would come in two stages over four to six years. First would be the 58 miles of river between Iron Gate and Keno dams. Next would be the 300 miles of habitat above Link River Dam at the outlet of Upper Klamath Lake.

PacifiCorp, which made no provision for salmon passage in its license application, is considering its options for appealing the recommendations, which could cost about $200 million, said spokesman Dave Kvamme. The utility can challenge the validity of the recommendations as well as offer cheaper alternatives, such as trapping fish and hauling them around the dams.

Based in Portland, PacifiCorp produces 8,400 megawatts of electricity for 1.6 million customers in Oregon, California, Washington, Idaho, Utah and Wyoming. It was recently purchased by MidAmerican Energy Holdings Co. of Des Moines, Iowa.

The Copco No. 1, Copco No. 2, J.C. Boyle and Iron Gate dams produce 151 megawatts, enough to serve 70,000 customers. The 50-year license expired this month, and has been extended a year.

The prescriptions also recommend a fish ladder for Keno Dam, which regulates irrigation water flowing back into the Klamath, and screens for turbines on Link River Dam, which already has new fish ladders.

The four Indian tribes on the river — the Klamath, Karuk, Hoopa and Yurok — praised the recommendations, saying they could ultimately lead to a decision by FERC or PacifiCorp to remove the dams.

“I think this is a watershed moment because now the economics start to change,’’ said Craig Tucker, Klamath project coordinator for the Karuk tribe. “Fulfilling these conditions is not going to be cheap and makes dam removal a more viable economic alternative.’’

Salmon in the Klamath have been beset by problems for more than a century. Gold mining in the 1850s caused extensive erosion that silted over spawning beds. In the early 1900s, a federal irrigation project diverted water from the river. A federal salmon egg collecting station cut off returns to the upper basin in 1910. The first of the dams, Copco No. 1, was completed in 1918 with no fish ladder, permanently shutting off access to the upper basin.