Sometime during the morning of Tuesday, November 30, 2021, a malfunction at the dam on Hebgen Lake near West Yellowstone, Montana caused the Madison River’s flows to drop to around 177 cubic feet per second (cfs). With water levels that low, fish were stranded outside of the Madison’s main channel. In addition, redds where brown trout were spawning were left exposed, potentially killing all the fertilized eggs on those redds.
The extent of the fish kill is unknown. On Wednesday, December 1, 2021, officials with Montana Fish, Wildlife, and Parks partnered with volunteers to help relocate fish that were stranded back in the main channel of the Madison River. Flows are still low, and there’s no current word on when the failure at Hebgen Dam might be fixed.
The Madison is closed from Ennis Lake upstream to Hebgen Dam.
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