I have hunted there a few times when I lived in Bozeman. I don't have a map of the elk migration routes for Montana yet (been trying to gather the data to make a map), but I know when they get a heavy snow in Yellowstone Park (2-3') the bulls start moving towards Ennis. The pass they use over the Madison Range is a little north of Hebgen Lake.
Here is a very handy and effective device I use to dispense corn with - but it could also be used to dispense any other seed or deer feed.
I had an old feeder that had a failed motor... I made a set of brackets to attach the feeder to the rear of the 4 wheeler - the lower one encircles the feeder and has a forward section with holes drilled in the outer ends of the bracket... these holes align with two 5/16" bolts that drilled into the rack of the 4 wheeler.
The upper bracket is an "L" shaped...