Yellowstone and Missouri trout shift toward fall streamer and baetis windows

What's biting

What's next

Water in the low to mid 40s means fish will be slow to wake. Plan around the warmest part of the afternoon, when temperatures peak and the olive hatches are most likely to bring trout up. Early mornings at 42°F will favor a slow, deep streamer presentation over a fast retrieve.

With flows steady across the four gauges, we expect stable conditions over the next few days unless a storm pushes the readings up. A rise in cfs with a drop in temperature would be the cue to move to bigger, darker streamers and slower drifts near banks and soft seams.

The First Quarter moon puts the brightest light in the evening, so dusk is worth a late session for streamer and low-light nymph fishing. Trout Unlimited's weight-matters tip is a good reminder to adjust split shot to the flow rather than fish one rig all day.

MT FWP Fishing News reports that spawning closures on some rivers began October 1, so check current regulations and section closures before you choose a stretch, especially on the Big Hole.

Context

Mid to late October is typically the transition from the late hatch season into the pre-winter feeding phase on Montana trout rivers. Brown Trout are moving toward spawning behavior, which tends to make them aggressive toward streamers but also more vulnerable, so many anglers give spawning fish and redds plenty of room. Water in the low 40s is on schedule for the date, and the olive and midge hatches that remain are generally small and concentrated in the afternoon.