Salmon are swimming again in the North Yuba River for the first time in close to a century. The fish are part of an innovative pilot project to study the feasibility of returning spring-run Chinook salmon to their historical spawning and rearing habitat in the mountains of Sierra County. … Using a proven technique used by other agencies but never before attempted by CDFW, fisheries scientists created dozens of man-made salmon redds, or nests, using a hydraulic injection system to clear the intended nests of silt. Scientists then carefully deposited the eggs up to a foot and a half deep within the gravel to mimic the actions of spawning adult salmon. … The first young fish were seen in the trap on Feb. 11. The young fish are being trucked downstream of Englebright Lake and released into the lower Yuba River to continue their migration to the Pacific Ocean.