[MTskibum]

May-June can be a tough time to float in montana, due to the highwaters from the snow meltoff.

Gallatin should be out of the question that time of year, and pretty much any time of year. Besides the fact that only the very lower stretches are actually floatable, and those very lower stretches are some of the worst water to float in southwest montana(stretches of the gallatin are good, but they are not floatable).

I would recomend the Madison, Bighole, or beaverhead myself. If you wanted southwest montana, or the bighorn in southcentral montana.