Written by: Trey Mullen, Brush Creek Ranch
Fall in Southern Wyoming is always a special time of the year. The dog days of summer are finally behind us, air and water temperatures have dramatically decreased since August, and fishing on the upper North Platte kicks into high gear before winter moves in and locks the fishery down until next spring. Our fall days often begin with frost on the ground and end with ample amounts of sunshine and fishing in a tee shirt. These massive temperature swings cause a variety of different insects to hatch throughout the day, creating optimal fishing conditions from sunup to sundown.
Prolific hatches, such as Tricos and BWOs, can account for the majority of a trout’s diet on certain days, but the number of terrestrials buzzing the banks is still high. The browns are becoming more and more territorial as spawning season approaches, so a small well-presented streamer can be key to hooking a big fish. Float season has officially wrapped up, and the low, cold, clear flows of the Platte make for ideal wading conditions. You’ll often see large pods of fish feeding on small surface flies in the few lingering deep holes, and you have a good chance of spotting a big brown or rainbow hanging in the shallow riffles looking for a larger meal.
Here is our Top 10 Fall Flies to have in your box on the upper North Platte to make sure all your bases are covered while wading this wild freestone fishery in September and October.
[Click the name of each fly to be taken to a place to buy, a recipe, or a video.]
1. Sunken Trico Spinner (size 20)
A huge portion of the fishes’ diet in the fall consists of Tricos. Fish really key-in on all stages of these tiny black-and-white insects: nymphs, duns, and spent adults. Use a Trico as your trailing fly, and don’t apply floatant–let it sink.
2. Parachute BWO (size 18)
This fly can be used as a point fly in front of a Trico spinner, or used during a BWO hatch. These small mayflies are likely the second-most prolific hatch we see on the North Platte during the fall months and will hatch all throughout the day.
3. Barr’s Emerger (Black/White or Olive, size 18)
Barr’s Emerger is good general nymph for the fall on the North Platte. Fish are likely eating this bug as a BWO or as a Trico nymph. We like to use this in conjunction with a larger bug on our nymph rigs in the few deep holes left on the river. Drop it beneath a dry fly for fish feeding on emergers just below the surface.
4. Juju Baetis (size 16)
We prefer the tungsten beaded version, so we have a slightly quicker sink rate, but we find they work in any color. Again, it’s a great all-around nymph in fall as our trout start to key on smaller bugs as their main food source.
5. Parachute Hopper (Tan, Olive, Yellow, sizes 10 and 12)
Hoppers are still prevalent in our area throughout September. Though a lot of fish pod-up and feed on small Trico hatches for most of the day, sometimes throwing something big and out of the normal will get the attention of big fish hanging in small water.
6. Platte River Spider (Yellow, sizes 6 and 8)
Streamers that are less “loud and flashy” tend to be better producers for us in the fall. We love the super slender profile of the Spider, and it works great as a trailing streamer if you’d like to throw it in conjunction with a larger pattern. Small water often calls for smaller flies, and the spider is the perfect solution for hooking that fish in skinny water.
7. Thin Mint (Black, sizes 6 and 8)
The Thin Mint is our go-to streamer throughout the year, especially so in the fall months, and it works well in tandem with the spider. Put this as your lead fly, preferably with a tungsten bead to get your optimal sink rate.
8. Egg Pattern (all colors, 10 and 12mm)
Once the browns start spawning in the Platte, rainbows will stack up below them feeding on their eggs. Eggs in general are mixed into the water column, and some of our biggest rainbows of the season will come on fall egg patterns in September and October.
9. Royal PMX (sizes 6 and 8)
The PMX is a great general attractor dry fly during this time of year. We love to use this highly visible, buoyant pattern as a point fly in a dry dropper rig. It works great as an indicator, but it’s certainly not uncommon to see a big trout come up and feed on this terrestrial pattern.
10. Soft Hackles
Any Soft Hackle–such as a Partridge and Orange or Hare’s Ear–works well in size 14 or 16. If we can’t seem to find a pod of fish feeding on the surface and the big guys aren’t looking to move to eat a streamer, swinging Soft Hackles through shallow riffles will always produce a hungry trout on the North Platte.
Trey Mullen is a guide at Brush Creek Ranch in Saratoga, Wyoming.