Oregon, California, the federal government and others have agreed to go forward with a plan to remove four hydroelectric dams in the Pacific Northwest without approval from a reluctant Congress, a spokesman for dam owner PacifiCorp said Monday. Tearing down the dams would be a major victory for tribes that have fought for years to restore the river for salmon they rely on for subsistence and ceremony. The move also could breathe new life into a struggling effort to allocate more water for farmers and ranchers in the drought-stricken Klamath basin.