I sooner cut off my pinkie than tell you where to find "a turkey".
That said, you already know the answer to get you started.
For the time being turkey populations are solid across Montana. Look on line at F & G website to see how the State is sectioned off for tag opportunity. Most non residents coming from the East don't want to drive any farther than necessary so public land on the East end gets visitors. There is plenty of ground...this isn't your neighbors farm. Start with National Forest but also consider BLM and State ground. Every significant river corridor has turkeys. Most public land in the East which has timber is worth checking. You have to be willing to make an effort....which involves alot of driving and risk with inclement weather( spring blizzards, which eventually turn the back roads to impassable mud). It might take more than one trip. Look beyond things and enjoy yourself. You should WANT to come to Montana for more than just killing a bird and moving on. I have no sympathy for those guys that are trying to kill a turkey in every state and are locked in on gun and run.
So as I said, you already have the answer, as indicated in your original post. If you bump in to people while hunting...walk further, or relocate a few miles. If you know how to hunt turkeys, then the rest is cake walk.
Merriam can cover alot of ground from winter staging to spring.
Good luck.