Historian Peterson joins a growing list of writers criticizing the damming of the Columbia River system at the expense of the migrating salmon population. In a dry but lucid account, Petersen focuses on the vision, first propounded in the mid-19th century by miners and by wheat farmers upstream from the Snake's confluence with the Columbia, of an unimpeded, navigable waterway to the Pacific. The idea began to reach fruition when Bonneville Dam was started in the 1930s, but it was not until 1975, after four dams had sprouted along the Snake, that ``slackwater'' reached Lewiston, Idaho. Long before then, it had become apparent that fish ladders permitting the upstream migration of spawning salmon over the large dams were not working. But as Petersen avers, the Army Corps of Engineers, supported by lobbying groups such as the Inland Empire Waterways Association, ignored biologists' warnings and blamed other factors, such as commercial fishing, for what was to become a 95 percent mortality rate for fish having to pass the dams. A major victory for fish conservation came in 1988 when the federal government overruled the Corps' proposal to erect a fifth dam upstream from Lewiston. But Petersen warns that only drastic measures, such as cutting irrigation allotments, decreasing hydropower generation, and drawing down reservoirs will reverse the slaughter of salmon. An epilogue to this saga of dams and fish charitably spreads blame to all segments of society benefitting from the recreational, hydroelectric, and navigational advantages of living along the Snake and Columbia rivers, warning that the increasing demands for water from a thirsty California might offer a future threat to the health of the river. Slow but important reading for people who thought the Columbia River system just meant Bonneville or Grand Coulee Dam and who assumed that the government could set nature right by quick fixes.