About 1.2 million newly hatched Chinook salmon died at the Rapid River Fish Hatchery near Riggins, Idaho, after an oxygen-pump malfunction disrupted water flow, according to Idaho Fish and Game (IDFG).

The inch-long salmon represented roughly one-third of the hatchery’s annual production. They were scheduled for release in spring 2027 to begin their migration to the ocean and would not have returned as adults until 2030. The loss may have ripple effects on Chinook returns across the region—something many in Wyoming follow closely given the interconnected nature of Intermountain fisheries and conservation efforts.

IDFG says hatchery staff discovered the equipment failure on Nov. 18. The alarm system meant to alert workers to a malfunction also failed. Although staff quickly switched to a

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