BOISE, Idaho -- More endangered sockeye salmon have made the 900-mile journey from the Pacific Ocean to central Idaho's high-elevation Redfish Lake this fall than in any previous year going back nearly six decades.

Some 1,400 fish have returned so far from a population that in the 1990s bumped along with one and sometimes no fish making it to the lake, ultimately becoming the focus of an intense state and federal effort to prevent the unique population from extinction.

The last time sockeye numbers exceeded the current run was 1955 when 4,361 fish returned to Redfish Lake, Fish and Game records say.

Get Breaking News Delivered to Your Inbox

"For about 20 years it has operated as a brood-stock program, a safety net program to prevent the extinction of this fish," said Jeff Heindel of the Idaho Department of Fish and Game. "I don't think anybody ever dreamed of where we're at now."

Fishery managers even envision a sport and tribal fishery within a decade due to extra fish.

A dam on the Salmon River built in the early 1900s blocked salmon for several decades from reaching Redfish Lake, itself named after the red-colored sockeye that once arrived there in abundance. Additional dams on the Snake and Columbia rivers added to the fish's challenges in succeeding years.

Through recent discoveries made possible by genetic testing, Heindel said, biologists have come to believe that one of the reasons the population didn't blink out in the following decades is due to non-migratory sockeye that never left Redfish Lake. There they survived through brutal winters with limited food resources and grew into adults - smaller than their ocean-going relatives - and produced offspring.

Some adventurous percentage of those offspring, however, made the risky journey to the food-rich ocean. The result, biologists say, is that the current fish are genetic descendants of the sockeye that first reached the 6,800-foot elevation lake in the Stanley Basin after the last ice age. The population represents the longest distance traveled to the highest elevation of any sockeye salmon run.

The run was listed as endangered under the Endangered Species Act in 1991. That kicked off a hatchery program that at first had only a handful of returning fish to propagate the species. The program received a big boost last fall with the opening of the Springfield Fish Hatchery in eastern Idaho.

The 200,000 juvenile salmon, called smolts, produced at the hatchery will double the number of sockeye released into the system this spring. By this time next year the hatchery aims to be at full production with about a million eggs, Heindel said.

Wild fish are also increasing. Ultimately, Heindel said, the recovery plan is to have 1,000 or more fish spawning in Redfish Lake for multiple generations, and at least 500 spawning in one of four other lakes in the basin. About 2,000 adult sockeye, a combination of wild and hatchery fish, are in Redfish Lake this year. They typically start spawning in early October.

The ramifications of a recovering Stanley Basin sockeye run extend far downstream, Heindel noted. Currently, some sport fishing seasons for non-listed sockeye from other river systems close as a result of mathematical models that predict how many protected Stanley Basin sockeye are being inadvertently killed.

A healthy Stanley Basin run would mean those fishing seasons could remain open longer. It could also mean a tribal fishery for subsistence and ceremonial purposes for the Shoshone-Bannock Tribe, a key player in helping bring the run back from the brink.

"It would be a great thing to be able to harvest these fish and make it meaningful to our people," said Chad Colter, the tribe's director of Fish and Wildlife. "We'd like to be able to get folks up there so they can catch fish."