The Stillwater is a free-stone river that flows out of the gorgeous Beartooth Mountain Range cutting its way through granite rocks that creates a gorgeous backdrop, movies such as The Horse Whisper and A River Runs Through It chose areas on this river to film their breathtaking scenes. If a list were ever compiled of misnamed rivers, then surely the Stillwater would be near the top of the list. Despite its name, the Stillwater River has whitewater, drops, rocks, and a very swift current depending on the current flow rate.
This is definitely a dry fly fishing river and fishing this pocket water stream with a big hopper or stonefly pattern can be awesome with strong, fighting cutthroats, rainbows, brook trout, and brown trout averaging 10-16″, though fish up to 22″ are possible.
Typically fishing this stream starts by early July via rafts but, good wade fishing can also be had in the early spring with very good mayfly hatches starting around early March through mid-May. During the summer the Stillwater produces some of the best dry fly fishing in Montana.
March Brown's and Baetis are the highlights of the Spring season and wade fishing is often the best option. As flows are higher and we start using rafts to effectively fish we see hatches of PMDs, Golden Stones, Yellow sallies, and Caddis. As the summer heat kicks in major hatches subside and various attractors, grasshoppers, beetles, and ants are the norm.
**Content Credit: Rocky Fork Outfitters
In my opinion, the Stillwater is the finest fishery in the State of Montana and it is relatively unknown. With a little forethought, you can have the place to yourself. While the fish are typically not huge, they are plentiful with approximately 3,000 fish per river mile. Browns predominate in the upper reaches, while rainbows comprise about 70 percent of the lower rivers‟ trout population. During the spring, the fish average 14 to 16 inches due to an influx of large spring spawners from the Yellowstone River. During the summer, the typical fish is approximately 12 to 13 inches long. The months of March, April and early May are incredible fishing if you know the river and its moods.
The upper river runs from the Forest Service boundary to the confluence of the Rosebuds. The lower river extends from this point to the confluence of the Yellowstone. River characteristics differ between these two segments. The upper river is faster, half the size of the lower river, and is more difficult to wade. There is also a portion of the Stillwater within the Absaroka-Beartooth Wilderness that I refer to as the headwaters. I do not fish this area since it is contains a bazillion little brook trout and not much more.
Hatches are prolific and predictable as described below under the topic “Seasons of the Fisher” found later in this document. Mayflies begin the dry fly season followed by caddis, giant golden stoneflies, more mayflies, and then hoppers. Streamers, (minnow imitations) are available to the fish year-round and I recommend trying them if nothing else works.
Wading on the Stillwater can challenge even the most experienced angler. The river bottom consists of bowling ball sized cobbles and larger boulders. During the summer and fall, they become coated with algae growth and are very slick until the algae die in late September. During the run-off and immediately after, wade fishing is very difficult due to high water and the challenging wading conditions, although the fishing is excellent if you are floating.
Fly selection is not complicated. Please refer to the section of this document entitled “Bug Activity” for an accurate chronology of flies to use during various times of the fishing year. Generally speaking, unless you are faced with specific hatch, big bushy, white-winged dry flies will usually catch the most fish during the summer. If you are fishing during the spring, summer, or fall and no surface activity is evident, try a #14 bead head impressionistic nymph near the bottom and you‟ll catch fish.