October is here and it is time to swing for the fences! October is well known for being one of the best months for landing trophy sized brown trout. Browns will be beginning to spawn in November but they are already moving in the rivers and becoming more aggressive. The fish are colored up and spectacular right now. We have already seen several big browns over 22” come to the net in the last few days. The hunt for big fish should only get better as we move farther into the fall. So where to go to target huge browns? Any of the larger river systems that hold big fish can produce a monster including the Yellowstone, Lower Madison, Upper Madison, Jefferson and Missouri to name a few. There are also some interesting locations where big browns run out of lakes and into rivers that include the Madison in Yellowstone Park, the Madison between the lakes and the Missouri both above Canyon Ferry and between the lakes near Beaver Creek. The better known fall spawning runs aren’t a secret so expect to see a few other anglers on the more famous ones like the Madison in the park and between the lakes on the Mo. Some of the “regular rivers” like the Yellowstone and Madison are still a great bet in the fall and you won’t see a lot of pressure and you often have a great shot at roping big fish when playing with the resident population. Big trout fall to a variety of patterns and techniques. Stripping streamers on cloudy days can be exciting and productive, especially when the water temps aren’t too cold. As water temps become cooler traditional nymphing techniques are still productive. Dead drifting favorite streamers trailed by baetis nymphs is a good bet. Egg patterns also become productive again since both whitefish and browns spawn in the fall. Fall water temperatures result in great fishing on all of our regular summer time favorites like the Gallatin, Upper Madison and Yellowstone but there are several low elevation fisheries that come into shape in the fall. Some of the waters around Three Forks like the Lower Madison, Jefferson and Missouri are too warm most of the summer but when temps start dropping they are a viable option. The catch on the lower rivers is that there aren’t a lot of trout but if you don’t mind just a few hookups it can be a fresh option this time of year. October isn’t completely about catching huge browns. There is also some great dry fly fishing to be had in the fall months. Baetis mayflies rule the roost when it comes to autumn hatches. These smaller size 18 and 20” insects will be in much greater abundance on cloudy days but even on a sunny day they can be important. Don’t forget about terrestrials in early October. Hoppers and ants can still turn fish on a warm and sunny afternoon in the fall. If you are a dry fly aficionado the spring creeks near Livingston are a great option with reduced rates and a daily hatch of BWO’s.
Water levels, although still on the low side increase in October when irrigation ends. In rivers above the irrigation they are mostly holding steady now at their base levels. Water temperatures are declining and fish are adjusting to softer water so avoid the riffles and look for slower holding water. Almost all fisheries around the state are now an option from tiny meadow streams to low elevation waters but the smaller mountain streams are tougher in cooler temps. The lower reaches of rivers have great water temps right now and are a good place to target trophy browns and rainbows. The productive fishing hours are now in the later morning and afternoon. Fish are still looking for the occasional hopper but the baetis hatches are getting thicker and are driving surface action. Streamer fishing is also getting better by the day as the big browns become unsettled before the spawn.
Although there are still some hoppers flying about, terrestrial fishing is slowing down. Baetis hatches are becoming regular and we have seen some very strong hatches on heavily overcast days and this should only get better. There are some bigger drakes mixed in with the baetis which trout love so a larger size 12 wulff pattern can work wonders. If you have some cloud cover be prepared to target rising fish in foam lines and seams. Make sure you have some baetis emergers to fish behind a dun.
Hoppers and ants can still take fish in October even though they are not as common as earlier in the fall. On warmer sunny days they are still worth a try. Mayflies are starting to become more important as the mahogany duns, drakes and especially baetis duns are popping in the late mornings and afternoon. For nymphing trout will start moving for a lot of sculpins but if nocturnal stones are around a size 6 rubber legs will still produce. For dropper nymphs try smaller patterns on more pressured waters. Baetis are just starting to hatch in force and are an important food source for the trout as nymphs and small size 20 beatis emergers can be deadly this time of year. Smaller droppers and finer flourcarbon tippet sometimes makes a difference but no need to drop to anything below 5x unless you are on a spring creek. Browns are starting to move and egg patterns can also produce in the late fall.
Water temps are cooler and trout have moved out of the heavy water and riffles in favor of softer holding water. On larger rivers look for slow inside corners below riffles, slicks, slow seams and foam eddies. On smaller streams the slower pools or transition current where it slows below the riffles is where you will find trout. Ignore the pocket water and riffles that were so productive in the late summer and early fall – the fish aren’t there anymore.