DENVER (AP) — Another rare Colorado River fish has been pulled back from the brink of extinction, the second comeback this year for a species unique to the Southwestern U.S.

The U.S. Fish and Wildlife Service plans to announce Thursday that it will recommend reclassifying the ancient and odd-looking razorback sucker from endangered to threatened, meaning it is still at risk of extinction, but the danger is no longer immediate.

The Associated Press was briefed on the plans before the official announcement.

Hundreds of thousands of razorbacks once thrived in the Colorado River and its tributaries, which flow across seven states and Mexico.

By the 1980s they had dwindled to about 100. Researchers blame non-native predator fish that attacked and ate the razorbacks and dams that disrupted their habitat.

Their numbers have bounced back to between 54,000 and 59,000 today, thanks to a multimillion-dollar effort that enlisted the help of hatcheries, dam operators, landowners, native American tribes and state and federal agencies.

“It’s a work in progress,” said Tom Chart, director of the Upper Colorado River Endangered Fish Recovery Program. “We get more fish out in the system, they’re showing up in more places, they’re spawning in more locations.”

Chart’s program oversees the campaign to restore the razorback sucker and three other fish, all of them found only in the Colorado River system.