Conditions look prime for fall fishing in Yellowstone National Park this week. Cold, wet weather is finally in the forecast, which is exactly what we’ve been waiting for to jump-start fall hatches of Baetis mayflies and kick migratory trout activity into gear.

HERE ARE THIS WEEK'S STANDOUTS. 

FIREHOLE RIVER

The forecast couldn't look better for afternoon hatches of baetis mayflies and rising trpout on the Firehole. With high temps struggling to reach the high 40s, expect to see the best insect activity and rising fish in the afternoons. 

MADISON RIVER

Despite the bright, bluebird weather, some stellar fish have been found on the Madison in the Park this week. Most of the best action has come from nymphs fished deep, but opportunities to convince fish to chase a streamer or move toward the surface to take a swung soft hackle should increase in spades with the upcoming scuzzy weather.

These are the conditions we look for on the Madison in October. We anticipate seeing a fresh push of migratory browns and rainbows into the system from Hebgen Lake, while lower light levels and cooler temperatures should have fish already in the river feeling more rambunctious and willing to move throughout the day.

GIBBON RIVER

The Gibbon will benefit from the cold, gray weather as well, with likely a few more large lake fish sliding up into the pocket water below Gibbon Falls. This is fun water to prospect with small, heavily weighted streamers or nymphs, working methodically through the deeper pockets, slots, and softer edges where migrating fish can settle in.

When those larger migratory fish are hard to find, the resident population of brown trout should be more than willing to keep you occupied. Cooler temperatures and low light should have them feeling increasingly comfortable and aggressive as we move deeper into October.

GALLATIN RIVER

All games are in play on the Park stretch of the Gallatin River this week. Afternoon Baetis hatches should bring some fish to the surface, particularly in flat tailouts, slower seams, and small pockets of calm water along undercut banks. Keep an eye out for subtle rises in these softer spots as the bugs begin to emerge.

Nymphing the deeper runs and pools with caddis and Baetis patterns should remain productive throughout the day. Small streamers are also well worth fishing in the deeper pockets and along structure, especially under the cloud cover forecast for this week.

With dry flies, nymphs, and streamers all viable options, the Gallatin should provide plenty of fun from late morning through the afternoon.

YELLOWSTONE RIVER

As we slide deeper into October and the forecast turns scuzzy, the lowest reaches of the Yellowstone River from Knowles Falls to the town of Gardiner will provide good opportunities to hunt large brown trout moving upstream into Park waters from Paradise Valley.

Cloud cover, cooler water, and lower light should create better conditions for streamer fishing throughout the day. Focus on deeper runs that provide migrating fish a place to stop and rest as they work their way upstream.

A strong population of resident Yellowstone Cutthroat trout, hybrids, and rainbows should provide some action in between bouts with large migratory browns. 

SLOUGH CREEK, LAMAR RIVER & SODA BUTTE CREEK

Sadly, we’ve reached that point in the season when the three Cutthroat gems in the Northeast Corner of the Park are no longer a great option. The recent streak of warm, dry weather extended the season up there for a bit, but cold temperatures and the near guarantee of rain or snow in the forecast will put an end to the “second summer” we’ve been enjoying in the Cutthroat Corner.

Slough Creek, the Lamar River, and Soda Butte Creek are all heavily influenced by cold overnight temperatures this time of year, and the upcoming weather will only push water temps lower. Hatches become increasingly sparse, and the cutthroat simply aren’t as active or willing to feed for long stretches of the day.

There may still be brief windows of activity if conditions line up, but with so many better fall options elsewhere in the Park, we’d focus our efforts on the waters to the west and south this week.