2025 Montana Snowpack Update: What It Means for Bozeman Fly Fishing

As of March 26, 2025, the snowpack in Southwest Montana’s major river basins—the Madison, Yellowstone, Gallatin, and Jefferson—offers a favorable outlook for the upcoming fly fishing season. Snow Water Equivalent (SWE) levels, which indicate the amount of water stored in the snowpack, are currently hovering around long-term averages. These rivers, home to some of the best fly fishing in Montana, are poised for a productive and exciting season.

Current Snowpack Conditions

A quick peek at the USDA NRCS Montana SNOTEL data shows encouraging numbers:

Madison River Basin: SWE is at 100% of the median for this date.

Gallatin River Basin: SWE stands at 105% of the median.

Upper Yellowstone River Basin: SWE is at 105% of the median.

Jefferson River Basin: SWE is at 95% of the median.

Spring is typically a wet time of year in Montana, with temperatures fluctuating from below freezing to over 70°F. Weather systems move quickly this time of year, often bringing significant moisture to the high country. Given current trends, we’re optimistic about river conditions for the remainder of 2025.

While much of March has been mild—leading to melting at lower elevations—the mountains have continued to accumulate snow. February brought steady snowfall and colder temperatures, which laid a solid foundation for this year’s Montana snowpack.

Implications for River Flows and Fly Fishing

SWE levels play a critical role in determining the timing and volume of spring runoff, which directly affects river flows and fishing conditions. Near or above-average SWE in the Madison, Gallatin, and Yellowstone basins suggests a "normal" runoff season—welcome news for Bozeman fly fishing enthusiasts.

Expect high water conditions on the Gallatin and Yellowstone Rivers to begin in early May and extend into late June. The Madison River typically sees a shorter window of challenging conditions between mid-May and mid-June but often remains fishable during most of the runoff.

2025 Fly Fishing Outlook

Montana fly fishing is just beginning to wake up after a long, cold winter. As the weather warms, lower elevation streams and small rivers are experiencing fluctuating flows due to fast-melting snow. This “yo-yo” effect makes it important to check streamflow conditions before heading out—especially on rivers like the Jefferson and Gallatin, which fish best when flows are stable or dropping.

Pre-Runoff Fly Fishing Near Bozeman

Bozeman fly fishing in early spring can be spectacular:

• Blue-winged olive hatches on the Lower Madison and Yellowstone Rivers provide reliable dry fly action on mild, overcast days through April.
• Mother’s Day Caddis hatch typically kicks off on the Lower Madison around the third week of April. The timing varies annually, but look for it once daytime highs hit the 70s consistently after mid-April. This hatch soon follows on the Yellowstone River near Livingston, usually in early May.
• Nymph and streamer fishing on the Madison River is excellent from $3 Bridge to Ennis during the early season.

The Best Fly Fishing in Montana During Runoff

Given the current snowpack levels, we’re expecting a more traditional runoff season compared to recent drought years. Most rivers near Bozeman will experience difficult fishing conditions in May and June. Historically, runoff intensifies around May 10 and gradually tapers off throughout June.

• Missouri River near Craig, Montana: This tailwater fishes exceptionally well during runoff. Flows will rise as upstream reservoirs fill, but releases from Holter Dam are typically steady and do not hinder fishing.
• Stillwater fly fishing on lakes like Hebgen and Harrison: These reservoirs provide great action in May and June. Use nymph rigs with leeches and chironomids along drop-offs and shoreline contours.
• Streamer fishing on the Jefferson and Big Hole Rivers: Big brown trout hunt actively during flow drops caused by intermittent cold fronts through May.

Top Bozeman Fly Fishing Prospects for 2025 Summer

Based on current snowpack trends, here is the anticipated timing of three key fly fishing events near Bozeman

• Salmonflies should begin appearing around June 23 on the Upper Madison River. While exact timing depends on weather, this is a reliable estimate for planning early summer Montana fly fishing trips.
• Expect prime conditions on the Gallatin, Yellowstone, and Madison Rivers throughout July, with continued strong fishing from late August through October. A cool, wet early summer could even lead to excellent fishing in late July and early August.
• Hopper fishing will pick up in late July on the Lower Yellowstone River and progress upstream into the Upper Yellowstone and Madison as summer advances and aquatic hatches slow.

Why Montana Snowpack Matters

Montana snowpack is a vital indicator of fishing conditions in our region. It sets the stage for the season by feeding rivers, maintaining cool water temperatures, and sustaining fish populations. While spring rains and summer temperatures are unpredictable, snowpack provides a crucial early-season baseline for planning your Bozeman fly fishing adventures.

With 25 years of experience guiding anglers through every type of season, we know how to adjust and deliver exceptional trips no matter what the weather brings. This year’s snowpack suggests a strong start and a potentially excellent fishing season across Southwest Montana.

Fins and Feathers Guide Service has been outfitting Montana fly fishing trips for over two decades. We’ve helped anglers make the most of both drought years and record runoff seasons. The 2025 outlook is among the best we’ve seen in recent years.

Book your guided Bozeman fly fishing trip with us online, via e-mail, or by calling 1-406-468-5019. Let our experienced Montana fly fishing guides show you the best rivers, hatches, and techniques for an unforgettable experience on the water in 2025.