Yellowstone Park Fishing Report

This Yellowstone Park fishing report is valid from September 2, 2025 until water temperatures really cool off, which given the weather forecast will be awhile.

The best waters right now will be the roughest ones: canyon stretches of the Yellowstone, the Gardner between Osprey Falls and Boiling River as far as you can get from the few access points to this water post-flood, and the big small streams like Hellroaring. Most other water are not on our radar right now. You’ll see tons of people fishing Soda Butte, the Lamar close to the road, and the Lower Meadow of Slough, but did you really come all the way to Montana to combat fish?

NOTE: The Firehole, Gibbon downstream from Norris Campground, and Madison in YNP, as well as tributaries feeding these sections, are under 2:00PM aka “hoot owl” fishing closures. Got to stop at 2:00, no exceptions!.

Park Waters are presented in roughly their distance from us, then by water type for generalities like “small streams” and “lakes.”

Gardner River

The upper Gardner is getting too low and actually too cold before noon to be worthwhile. If you fish it, stick to the area below Sheepeater Cascade and Osprey Falls. Fish small hoppers or big mayfly-style attractor dries (Royal Wulff Cripple) trailing #16-18 beadheads. This area is rough and rugged, and if you don’t know how to access it safely, don’t do it.

The middle Gardner between Osprey Falls and Boiling River is in good shape, but it’s hampered by limited access. Your choices are the Osprey Falls Trail, the High Bridge, or hiking down from Mammoth Hot Springs. That’s it. The 2022 flood is still a bummer here. Fish a midsize hopper with a dense jig-style dropper, Euro-nymph the pockets with a stonefly (or stonefly/streamer crossover like the Zirdle or TJ Hooker) or nymph the deepest pools. This water sees heavy guide traffic into early October.

The lower Gardner below Boiling River is too warm and should be closed.

Hatches: Probably none of note until we see cooler weather.
Dry Flies: Hoppers and other terrestrials, maybe small attractors like Clacka Caddis and big Purple Hazy Cripples.
Nymphs & Wets: Generally #14-16 attractor nymphs like Princes, PT Spankers, etc. Below Osprey Falls, you might run these behind #4-6 stoneflies in the bigger pools.
Streamers: None.

Streamflow data graph for the Gardner River in Yellowstone Park

Gardner River – Flow

Yellowstone River – Black Canyon

Generally similar to the Yellowstone in Montana: high late afternoon water temps, scattered mayfly hatches, and okay terrestrial fishing. The further upstream you’re fishing, the more it’s worth fishing a big Chubby or hopper with a nymph dropper instead of smaller dry/dropper or dry/dry rigs. Streamer fishing is mostly limited to the upper canyon, roughly between the Lamar and Hellroaring Creek confluences.

Hatches: Limited importance, but some Tan Drakes (aka Drake Mackeral) and BWO are possible. They will get more likely the later in September we get.
Dry Flies: Various #8-14 hoppers (depends on section), #12-18 attractor dries leaning towards mayflies, ants.
Nymphs & Wets: #16-18 mayfly-type attractors throughout. The more remote areas will still fish on Princes and midsize stoneflies.
Streamers: No reason to get fancy. Fish a #4-6 black, white, or black and orange Woolly Bugger (the latter suggesting Salmonflies) with a #10-12 in whatever color on the dropper.

Note: Check the Lamar River streamflow graph below before fishing this stretch of the Yellowstone. The Lamar gauge is near the Yellowstone confluence, so sudden spikes at this age suggest muddy water is incoming in the Black Canyon.

Yellowstone River – Grand Canyon

Somewhat cooler than the Black Canyon. We are more inclined to fish a #8-12 hopper with a nymph dropper here than further downstream, since there aren’t any whitefish to eat the nymph before the trout get to them. Streamers are also a great choice except perhaps near the heavily-pressured water near Tower Falls.

Hatches: Similar to the Black Canyon.
Dry Flies: Pink Pookies, GFA, Yeti Hopper, Morrish Hopper, and similar larger foam hoppers. Big natural-colored Letorts can work, too. Fish a nymph on a long dropper.
Nymphs & Wets: Mostly #16-18 attractors like Princes, PT Spankers, Lightning Bugs, etc.
Streamers: No reason to get fancy. Fish a #4-6 black, white, or black and orange Woolly Bugger (the latter suggesting Salmonflies) with a #10-12 in whatever color on the dropper.

Note: Check the Yellowstone Lake Outlet flow graph below. Except following sudden thunderstorms, the Grand Canyon is usually fishable for the season once flows begin dropping in mid-late June. They may be fishable before, too, if overall flows are below normal, but even during high water years, the Grand Canyon clears fast once the lake outlet stops rising.

Yellowstone River – Headwaters and Lake to Falls

It is getting awfully late to expect much from this water, since most of the trout migrate back to Yellowstone Lake beginning right after the season opener July 1. Swing streamers unless you spot rising fish.

Hatches: Assorted Little Green Drakes, maybe Epeorus or Heptagenia, Tricos, this and that. Only match hatches if you see fish eating them.
Dry Flies: To match the above, plus smaller attractors such as Hazy Cripples.
Nymphs & Wets: Unlikely to work well unless you spot specific fish. If you do, the drift will be more important than the pattern.
Streamers: Various larger Woolly Buggers, Sculpzillas, Marabou Muddlers, and patterns that fish well on the swing, such as Montana Intruders.

Yellowstone River at Yellowstone Lake outlet streamflow data graph

Yellowstone River at the Yellowstone Lake Outlet – Flow

Lamar River, Slough Creek, and Soda Butte Creek

So very crowded anywhere near the road, and also near record low flows, which concentrates these crowds into smaller and smaller areas. You couldn’t pay us to fish here now. We mean it. We would refuse a guided trip to this water due to the crowds.

The one exception would be the canyon section of the Lamar, which is very physically demanding. That’s worth a shot if you’re a mountain goat.

The meadow areas will be almost “Pennsylvania on stocking day” crowded. If you can tolerate that, you’re hoping for hatches but fishing ants, beetles, bees, maybe some midges in the morning, and slender nymphs like Flashback Pheasant Tails.

Hatches: #14-16 Little Green Drakes, Tan Drakes (aka Drake Mackeral aka Hecuba aka Rusty Drakes), cream Baetis, a handful of #10-12 Drunella grandis Green Drakes, midges and Tricos in the morning. Hatches are likely to be sparse and fragmentary except if it clouds up. A little cold drizzle to scare away the casual anglers who might melt if they get wet will lead to great hatches.
Dry Flies: To match the above, plus ants, beetles, and bees. Standard hoppers are unlikely to work well except in the rough stretches, though little oddball hoppers you tie while you’re high might work in the meadows. There might be spruce moths in wooded sections of Soda Butte, which will also be slightly less crowded.
Nymphs & Wets: Lightly-weighted or unweighted Pheasant Tails, Copper Johns, Lightning Bug, Zebra Midge, Radiation Baetis, Perdigon, Gray CDC Emerging Dun. In rough areas, a #16 green Montana Prince is a good choice.
Streamers: None except maybe in the roughest portions of the Lamar, where Woolly Buggers and Sculpzillas are on the menu.

Note: Sudden spikes in flow in either graph below suggest muddy water either occurring or imminent. The Lamar graph is immediately upstream from the river’s confluence with the Yellowstone, so odds are the entire river from Soda Butte Creek down is muddy if this graph is showing a spike. The Soda Butte gauge is at the park boundary, so a spike there indicates mud that will hit lower Soda Butte in a couple hours and the Lamar and Yellowstone thereafter. Slough Creek is less prone to mud than either the Lamar or Soda Butte.

Lamar River – Flow

Soda Butte Creek – Flow

Firehole River

Now open until 2:00, but you really shouldn’t fish downstream of Biscuit Basin until water temps cool down quite a bit more. Above the Old Faithful closure, fish large ants or small hoppers with small nymph droppers.

Hatches:
Dry Flies:
Nymphs & Wets:
Streamers:

Note: The Old Faithful gauge is at the upstream end of the famous section of the Firehole. The West Yellowstone gauge is immediately upstream from the Firehole’s confluence with the Gibbon, downstream of all tributaries both hot and cold. Water temps will be lower and the water clearer the further upstream you travel.

Graph of flow data for the Firehole River at Old Faithful, WY

Firehole River at Old Faithful – Flow

Streamflow Graph for the Firehole River near Madison Junction, WY

Firehole River at Madison Jct. – Flow

Water Temperature Note: The lower Firehole River gets roughly half its water from geyser basins and therefore runs much warmer than anything else in the region. This is good early and late in the season, bad in the middle and even on hot/bright days after early June.

Firehole River trout are used to warm water temperatures and remain active until temps hit 70 degrees on a given day. Even so, when this gauge starts flirting with 75+ for the daily high, especially when nighttime water temps don’t drop below 67, it’s time to start fishing mornings-only upstream from Midway Geyser Basin. Once water temps reach the high 70s and do not drop below 70 at night (or don’t drop under 70 for an appreciable length of time), it’s time to fish only the “small stream” portion of the Firehole upstream from the Old Faithful closure zone, or to go elsewhere.

Firehole River at Madison Jct. – Water Temperature

Gibbon River

Closed at 2:00PM downstream of Norris Campground. You should not fish downstream of this point at all until temps cool off.

Upstream, fish smaller (#14-16) attractor dry/dropper combos for westslope cutts and grayling.

Hatches: Green Drakes, small stoneflies, various caddis. It is seldom necessary to match these insects upstream from Virginia Cascades.
Dry Flies: #14-16 Trudes, Clacka Caddis, Royal Wulff Cripples, etc. In the meadow near Norris Campground, match the hatch.
Nymphs & Wets: #16-18 Princes, Pheasant Tails, Lightning Bugs, and similar small yet slightly flashy attractors.
Streamers: None.

Gibbon River – Flow

Madison River

Closed at 2:00PM. That said, the water from the Barns Pools down to Hebgen Lake cools off a great deal overnight this time of year. The air temps will be in the 40s every night, and the stretch above is all shallow riffles where the water mixes with this cold air. Some fall-run browns will be nosing into the Barns Pools and Beaver Meadows, but not really moving any higher due to the shallow water (that is still getting toasty in late afternoon). So these big boys and girls are worth targeting for a couple hours right after dawn before you go elsewhere.

Hatches:
Dry Flies:
Nymphs & Wets: Various stoneflies, big soft hackles, San Juan Worms, and assorted “junk.” None of this imitates anything. You are “steelhead fishing” for the run-up trout.
Streamers: Woolly Buggers, Zonkers, and the like. For now, dead-drift them rather than expecting much on the strip or swing.

Graph of Madison River Flow at West Yellowstone, MT

Madison River Near West Yellowstone – Flow

Park Small Streams

The meadow streams are now really too low.

The rough and rocky streams are a much better choice, especially the larger streams (though smaller ones like Lava are also okay.) Where brookies are involved, fish #14 attractor dries trailing #16-18 beadheads. Where the trout are larger, you might go a notch larger on your flies, and be prepared to get a bit more creative with fly choice.

Lamar River tributaries (especially upper mainstem tribs like Cache Creek) are good bets, though the big fish are mostly back in the parent streams now. The top fishing comes during hatches of the same insects mentioned above for the main streams. Good hopper/dropper fishing is also possible.

Hatches: Unimportant on the rough streams we generally suggest. On Lamar tributaries, spillover hatches from the major streams are possible.
Dry Flies: #12-16 attractors like small Chubby Chernobyls, Trudes, and Clacka Caddis. On streams holding trout other than brookies, larger and/or weirder hoppers may be on the menu.
Nymphs & Wets: #16 attractors like Princes, Copper Johns, etc.
Streamers: None.

Park Lakes and Ponds

All are poor choices until it starts to cool off. Surface temps are just too high.

Hatches:
Dry Flies:
Nymphs & Wets:
Streamers: