I'll chime in on the run-off theme too. For a Plan B, I would suggest looking for some ponds and lakes, and use either the boat or bring float tubes.

There are some/a indian reservation in north central MT. that are supposed to offer fishing for hog 'bows. Somewhere around Havre maybe, sorry don't have a map here.

A great guide but out of print I think is The Montana Anglers Guide by Fothergill & ?. Has all the rivers, detailed pullout maps, good info, spiral bound and water resistant. Search the used book sources for one - you won't be disappointed
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