The pike are coming

The official Montana fishing regulations now say that there is no limit on northern pike in the East Gallatin , Gallatin, and Madison rivers (along with the Jefferson). The fact that pike are explicitly addressed apparently means they're definitely in there. I only wish they'd have included the regulation that it's mandatory to keep them, like lake trout in Yellowstone Lake.
There has been a rumor about pike the East for a while, but as far as I knew, it was only a rumor. There has been an official record of pike in the Jefferson for many months. And when looking into other pike sightings, I found an article in the Billings Gazette that mentions them in the lower Gallatin.
This column from the Montana Sporting Journal summarizes my thoughts.
There has been a well-known pike fishery around Toston Dam on the Missouri River for a while, where ice-fishers do quite well, apparently.
From the Gazette article:
"The source of the pike was apparently some ponds in the East Gallatin River valley. Those ponds were poisoned out by FWP last year. But before the poisoning, some fish got out and moved down the drainage."
Meaning they probably found their way into the East Gallatin in high-water, and migrated up through the East, mainstem Gallatin, and the Missouri.
The time has come for catch and keep - just get them Y-bones out and they're good eatin'. 
I'm gonna be seriously mad if/when a pike is found in the Big Hole.