1980 | Feather River Fish Hatchery, Oroville
The Oroville Dam was built with a specialized system of inclined intake towers to manage the temperatures of its outflow. Warmer water is taken from the upper levels in the reservoir to meet the requirements of rice farmers in the Butte County flatlands below. This fish hatchery requires much colder water from the deeper parts of the reservoir to simulate one of the primary conditions that king salmon would seek in their dam-eliminated spawning areas.
When I visited, this hatchery sacrificed and manually arranged for milt and eggs to be ‘mated’ for about 5,000 mature kings during their brief but intense spawning run (these were the far and fast swimmers; about two-thirds of the run now spawn naturally in areas below the dam). Normally the strongest would have gone much farther upstream, found suitable and safe gravel, made nests, spawned, and then died; their drifting or snagged remains might later be consumed by young ones for valuable nutrition during their return to the sea, where they in their turn might make three or four or sometimes five or more circumnavigations of the Pacific before returning to the highest and coldest waters of their home stream.
(From an entry in my water survey notebook, October 30, 1980.)