Reviving chinook salmon on the San Joaquin River will cost more than $20 million – which may sound like a lot of money for 40,000 fish. But this rare project will take years of work, scientists say.

Three-quarters of those fish will be spring-run salmon, a threatened species already in danger of extinction in California. In the San Joaquin, the fish will have to survive in the southernmost salmon fishery on the continent – where the water sometime gets a little too warm for them.

Scientists say they haven't found similar reintroductions of the threatened spring-run salmon in a river like the San Joaquin, which had been dry in places for more than a half century. Federal officials need to breed a resilient fish for this river.

This month, federal officials began revealing details of the project that will include a $14.5 million hatchery near Friant Dam and more than $7 million to operate it for a decade.

The total is a small slice of the restoration cost, which could run as high as $1 billion. Farm critics say it would be cheaper to skip the expense of salmon restoration and just allow other fish, such as trout and blue gill, to populate the river

Read the full story at fresnobee.com.