What is "normal" for spring runoff these days?

What is "normal" for spring runoff these days?

What is "normal" for spring runoff these days?

Spring has sprung, snow is soft on the slopes, green grass is popping up in the valley, and drift boats are bobbling along our rivers. The other day I saw a few caddis bouncing around on the Yellowstone. Caddis on the Yellowstone in late March? That’s not normal.


But as more and more anglers proclaim March is the new April, it’s clear that our angling calendar has changed. Deniers of climate change are obviously not local anglers—with each passing year the first drift boat float of the season comes earlier than the last. So what is the new normal for anglers in southwest Montana? Here’s a quick prediction based on my observations over the past twenty years on the water.


Consistently good spring fishing. The opportunities to fish are more frequent than ever this spring. As a kid growing up, late March and early April were more about powder days than matching hatches. Nostalgia aside, anglers can now realistically fish most of March and anticipate prime dry fly fishing in April.


Above-average springtime streamflows. A similar thing happened this time last year. Our snowpack looked good with most statewide numbers hovering above 100 percent of normal. This year some basins are above 150 percent of normal, so we may see some more water come down earlier than usual. But as spring temperatures rose, so did the flows on our rivers and streams. Last year our rivers flowed well above their long-term average through most of April. We were still able to fish despite these higher flows, but anglers used tactics more commonly employed during runoff-type conditions. Larger flies and deeper nymph rigs were required.


Late summer stream flows are a wild card. If stream flows are double normal now, summer flows will be lower than average. For our late summer angling to be consistent with my teenage years, we need several spring snowstorms to drop the temperatures and some snow. If that doesn’t happen, expect higher flows and run-off like fishing conditions the next several weeks. Summer hatches will be sooner and late summer fishing will mean early morning fishing during the coolest time of the day.


Enjoy it while you can. Your idea of a day on the water may be T-shirts and flip-flops and casting large dry flies to hungry cutthroat trout. Those days can still happen, but if you want to maximize your angling, consider expanding your calendar. It may require purchasing a pair of quality waders and outerwear, but you will get to fish more. 


So get out there and enjoy the fishing now and be happy if you have to wear your extra layers.

Sign up for our newsletter

Gallatin River Guides

  • Gallatin River Guides Big Sky, Montana fly fishing store and guide service near Bozeman, Montana and Yellowstone National Park
  • 406-995-2290
  • [email protected]
Copyright 2020 Big Sky Montana Fishing Trips Bozeman Montana Gallatin River Guides Powered by Lightspeed
Credit Card MasterCard Visa American Express