Each year Montana rivers become swollen from the melting snow pack. Typically run off begins sometime in mid-late may and can extend into June and even July on big snow years. Despite the fact that some rivers are un-fishable and dangerous during run off, there is still great fishing to be had....sometimes the best of the year. Fly fishing in Montana is rarely crowded during runoff (except for some tailwaters) and water temperatures are kicking trout into feeding mode. Since it is still early in the season, trout have not received much pressure and are easy to fool.
1) Fish tail waters
Large reservoirs filter sediment out of rivers. Below the dams, water runs clear and fishing remains terrific during the high water run off time period. Rivers like the Bighorn, Beaverhead, and Missouri are world famous tailwaters. The Ruby and Madison are also tailwaters that remain fishable during most of runoff.
2) Fish spring creeks
Spring creeks originate from underground springs and stay cyrstal clear all year. They also do not fluctuate in flows and produce spectacular fishing in May and June. The PMD emergers during this time period producing terrific dry fly action. Montana's spring creeks are some of the best in the world!!!
3) Fish stillwaters
Lakes and irrigation reservoirs produce awesome fishing for very large trout. Often trout cruise the shallows allowing for anglers to site fish. Watching a 27" trout swim to your fly and then inhale it is truly a rush! The first brood of callibaetis mayfly hatches in June producing exceptional fishing. Weedbeds are still not established making May and early June an exceptional time to fish during run off.
4) Fish the high water!
When waters are rising fast, they become very muddy and fishing is poor. When waters begin to drop, they may still appear off color but fishing can be good. When visibility hits 12" and the waters are dropping, work the banks with big stonefly nymphs or streamers and hang on. Boats are a great tool for this type of fishing. Our Bozeman fly fishing guides often use the boats to work our way downstream, then jump out and fish the slower eddies where fish have concentrated to escape the high flows.