BOZEMAN — A parasite that caused a major die-off of mountain whitefish in the Yellowstone River has been discovered in two more southwestern Montana streams.
Montana Fish, Wildlife and Parks said Friday that the parasite was detected in the Big Hole River near Wise River in January and in the Gallatin River near Three Forks last year.
That brings the number of Montana rivers where it’s been found to 10.
Known as PKX, the parasite was blamed in the deaths of tens of thousands of whitefish in the Yellowstone last summer, prompting a weeks-long closure of the popular river.
It’s also been found in the Jefferson, Madison, East Gallatin, Shields, Boulder, Stillwater and Big Horn rivers. Only the Yellowstone had a documented fish kill.
Monitoring for PKX in other Montana streams is planned for the spring and summer.