The salmon were raised at a hatchery on the Feather River in Northern California. They were trucked to a pool at the base of Friant Dam on April 8th.
There they were kept in a floating pen long enough for this to register as their new home. A place they may have an inexplicable desire to return to someday.
U.S. Fish and Wildlife Service Biologist John Netto says the goal is to get the salmon to "imprint" on the smell of the water here.
On Thursday Netto and a dozen other biologists from the Fish and Wildlife Service and the National Marine Fisheries Service used nets to scoop up the young salmon.
The biologists formed a bucket brigade to haul them to insulated tanks on trucks about 50 yards on a road above the river, just below the dam.
From here the salmon are trucked about 100 miles downstream to where the Merced River meets the San Joaquin, near the town of Newman.
The reason for the long haul is because the San Joaquin River runs dry about 40 miles west of Fresno. It's water has been diverted for farm irrigation since Friant Dam was built, in the 1940's. The dam destroyed the historic salmon run.
After decades of legal battles the Natural Resources Defense Council, or NRDC, reached a settlement with agricultural interests to allow enough water to be returned to the river to restore the salmon run.
The restoration has been underway for seven years. However, the current drought threatened to derail the project.
Water allocations for the fish restoration were cut off, along with much of the irrigation water for agriculture.
The decision to truck the fish around the dry areas of the river keeps the program alive, without impacting the water supply.
Monty Schmitt of the NRDC describes this as a "monumental step forward in restoring the San Joaquin River and bringing it back to life."
Netto notes this will be the first Spring run of Chinook Salmon on the San Joaquin River in nearly 70 years.
If all goes well the fish will migrate down the rest of the river on their own, through the Delta and into San Francisco Bay and the open ocean.
Only a tiny fraction of the 54,000 fish are expected to return. The hope is that when they return, in two or three years, the river restoration project will have removed enough obstacles, and provided enough water that those survivors will make it back to the base of the dam.
The state is planning to build a massive fish hatchery nearby and eventually millions of salmon will learn to call this spot on the river their home and return to spawn.