From now through about October 20, ever-increasing numbers of brown trout will be entering the Madison, lower Firehole, lower Gibbon, and Gardner Rivers in Yellowstone Park. The run in these rivers has been underway for a while now, but the cool and wet weather we’ve been blessed with most of September has hurried things along and made for great fishing. The photos inserted in this entry were all caught in recent days on my (Walter’s) guide trips, but Ben, Bart, and Don are also putting their clients on LOTS of browns. Six to ten fish in the 14 to 18″ range with one or two often in the 20-22″ range is average, but there have been a couple trips recently when we’ve put experienced anglers on as many as TWENTY-FIVE to THIRTY-FIVE of these fish. You can’t plan on that, but it’s possible, especially when the weather sucks… Guide availability is very limited for another week, but after September 27 things open up dramatically. October is particularly empty, as usual. It’s hard to get as many clients as we’d like once mornings below 25 degrees and a few snow showers during an average week of fishing cross from “possible” to “likely.” For those who do brave the elements, big fish await.
For right now, nymphing is the best tactic. Stonefly nymphs trailing eggs or medium-sized attractor nymphs will bring the most fish, while streamers will bring a few aggressive smacks and potentially larger fish. This is particularly true when the light is flat or the weather is awful. The streamer bite will get steadily better through the middle of October. On the Madison, don’t hesitate to swing large, flashy soft hackles or even small steelhead flies. This river is ideal water for the swung fly, and most anglers swinging will be using big junk, so somewhat smaller (#8 to 14) wets can interest fish that are just spooked by the big streamers.
Fresh fish will continue to enter these rivers through the close of the park season on the first Sunday in November, but more and more of them start actively spawning after the middle of the month. From that point on, AVOID fishing shallow water to avoid bothering actively spawning fish (and to avoid trampling eggs). Fishing the deep water downstream of shallow spawning areas is productive right to the end of the season and does not bother active spawners. The deep water is the bar at 10:30PM –lots of fish are there looking for a fight. The shallow gravel is the bedroom at midnight.
Look for the Lewis run to begin around October 15 between Lewis and Shoshone Lakes and immediately downstream of Lewis Lake, and in the Snake and Lewis near the South Boundary of YNP around October 1. The browns are also getting frisky in the Yellowstone River outside the park, so you never know what a big streamer might bring.