Montana Fish, Wildlife and Parks is considering introducing westslope cutthroat trout to Camas Lake and Big Camas Creek.
Agency spokesman Dave Moser says that those are ideal locations because downstream waterfalls create barriers to other fish species.
The two water bodies currently support Yellowstone cutthroat stocked in the 1950s.
But Moser says Yellowstone cutthroat aren't native to the Missouri River drainage and officials would like to see Westslope cutthroat returned.
A public meeting is planned Thursday at White Sulphur Springs to discuss the plan.
Westslope cutthroat trout are one of two subspecies of trout in Montana, but they've been threatened with habitat loss and hybridization with rainbow trout and Yellowstone cutthroat.