Perched on a plywood scaffold over roaring waters, a Wenatchi father and son fished using long nets made by hand and under the cover of darkness so it was harder for salmon to spot them. Only a handful of their tribe still fish this way. Dams through the region’s system of rivers have electrified cities, irrigated crops and powered industry. But those dams also decimated salmon numbers and wiped out fishing grounds that were central to tribes’ ways of life.