Parks' Fly Shop guides and most visitors to our site focus on rivers in the northern half of Yellowstone Park, plus the Yellowstone river and its tributaries, area lakes, the spring creeks, and perhaps the Madison River. Other rivers that are slightly farther away are discussed here in less detail than rivers closer to our shop. If you would like more information about any of these locations, feel free to contact us.
The Snake and its tributary the Lewis are located at the south end of Yellowstone Park. Since the Snake, really the headwaters of the South Fork of the Snake, is an extreme backcountry river at its headwaters in Yellowstone Park, the Lewis is of more interest to anglers.
The Lewis originates in Shoshone Lake, the largest backcountry lake in the USA. Originally fishless, the upper river holds lake trout and browns. The river flows slightly less than four miles between Shoshone Lake and Lewis Lake. This is the only river section in the park where boats are allowed, but only non-motorized craft such as canoes and driftboats. If using a canoe, be sure to have outriggers. If using a kayak, be sure to have a spray skirt. These precautions are necessary because both Lewis and Shoshone Lakes are bitter cold and often suffer from high waves. The Lewis-Shoshone Channel is shallow and gravel-bottomed in its upper half, and just fast enough it cannot be rowed or paddled against. This section has a large fall run of browns from Shoshone Lake and is heavily pressured over the last couple weeks of the season. Egg flies and small, non-bead nymphs are usually the best bets for these fish, both due to the pressure and due to the crystal-clear water. The bottom half of the channel is deep, slow, and fjord-like. This area has a resident population of both lake and brown trout averaging 15-22 inches. The browns are typically shorter but fatter. This area was heavily burned in the 1988 fires and numerous downed trees line the banks, making fishing from a boat the best bet. Strip large streamers such as gray and white Double Bunnies and PT-Buggers along the downed logs. This section is fishable as soon as the ice goes off both the lakes, usually between the 5th and 15th of June.
The Lewis River continues at the outlet of Lewis Lake. The first mile of this section, down to a couple hundred yards above Lewis Falls, fishes similarly to the top of the Lewis Channel, though it probably sees somewhat fewer fish and somewhat less pressure. The immediate outlet section of the lake fishes well with streamers early in the season, for both browns and lake trout, and the resident fish in this section of river rise to caddis in June and early July. Access this section by hiking down from the Lewis Lake campground, by beaching a boat at the outlet, or by hiking up from Lewis Falls. This section is fishable as soon as the ice is off Lewis Lake, usually a couple days before it's off Shoshone.
The big pool immediately below Lewis Falls occasionally fishes well with streamers, for both lake and brown trout, but it is inconsistent. This pool can be accessed by walking up to the falls from the road crossing just downstream. The next couple miles of the Lewis parallel the road and are slow, wide, and glassy. PMD, Green and Gray Drakes, and terrestrials can all draw rises here, but the resident brown trout are both large and super-spooky. Experts only need apply, but some of the fish here reach 24 inches. Probably the best time to have a reasonable shot at these fish is on gray days in October, when they may chase big streamers. This section becomes fishable in mid-late June.
Below the Lewis Meadow, the Lewis cuts down into a 1000+ foot-deep canyon that is extremely difficult to access. Pick a spot where you think you can get down and go for it. The bottom of the canyon is accessable by walking down Crawfish Creek. Fish upstream or down. Another option is to park at the South Entrance Picnic Area and hike upstream. This section of the river is below several small waterfalls and has native cutts and whitefish as well as browns and a handful of lakers. The fish exhibit a wide size range: most will be small, but some real monsters are possible. Streamers, attractor dries, and caddis are good choices in the canyon. This section becomes fishable in mid-late June.
The Snake essentially parallels the southern boundary of Yellowstone Park for most of its course. Access is via the South Boundary Trail; only the last quarter-mile of the river is accessable from the South Entrance picnic area. The Snake is typically unfishable until mid-late July due to massive amounts of winter snow and the accompanying spring melt. The river flows in a gravel bed that is frequently rearranged by runoff. The primary structure is formed by riffle corners, especially those accompanied by logjams. Green Drakes, caddis, PMDs, BWO, and terrestrials will bring risers. Woolly Buggers, attractor dries, and even small mouse imitations are also good choices. The average fish in the Snake is not large, probably 8-12 inches, but occasional very large cutts and browns keep things interesting. These fish are probably migrants out of Jackson Lake downstream.
The Bechler and Falls Rivers originate on the other side of a ridge from the Lewis/Snake system. The Bechler is a tributary of the Falls, which flows west to join the Henry's Fork of the Snake in Idaho. A major hike is required for the best water in the system, which is on the Bechler. Some fishing on the Falls is available near the end of the Cave Falls Road, which is the primary access point to the system. We want to make clear that you should not base out of PFS to fish this area. Even the trailhead is about four hours from Gardiner. On the other hand, this is an extremely beautiful area, home to most of Yellowstone's waterfalls, including perhaps hundreds that have not been formally surveyed.
Extreme winter snow means this area does not become fishable until at least early July. Until late August, expect marshy terrain and immense numbers of mosquitoes and biting flies. The best fishing, if not the best catching, is in September and early October.
The character of both rivers is primarily shallow, steep, canyon pocket water. Small to medium-sized rainbows and cutthroats inhabit these sections. The Bechler Meadows are a profound exception. This three-mile meadow is home to the largest resident trout in the Park, including some rainbows that approach thirty inches in length. This is flat water with little cover for either trout or angler, so even the ten-inch fish in this section are super-spooky. The big fish have their Ph. Ds in wariness. Small terrestrials, Green Drakes, PMD, and BWO are the top flies for the meadows. Sight-nymphing with tiny midges or non-bead Pheasant Tails is also a good tactic. Bring your A-game. In the canyon water, a Trude/Prince or similar dry/dropper combo will usually do the trick.
The Shields is a small river that enters the Yellowstone just east of Livingston. It is primarily private in its lower reaches and is heavily dewatered in late summer. In the spring and early summer and again in the fall it can produce some good browns, especially on streamers. The upper river can be accessed via National Forest roads and US Hwy 89, and holds cutthroats. The Shields is subject to discoloration from returning irrigation water, thunderstorms, and especially spring runoff, which starts earlier here than on the other major tributaries of the Yellowstone. Both thunderstorms and early runoff can result in muddy enough water to make the Yellowstone downstream too muddy to fish. We do not run guide trips on this water, but supposedly some outfitters who have arrangements with some of the ornery landowners to access the lower river do well in the fall on runner browns.
The Boulder River and its many forks form the next drainage east of the Yellowstone, with its valley parallelling Paradise Valley. The Boulder enters the Yellowstone near Big Timber, about thirty miles east of Livingston. The lower Boulder flows in riffles and pools through ranch country, with many undercut banks that hold some very large browns and rainbows. Unfortunately, this section of the river is almost exclusively in private land (much of it owned by various extremely rich/famous people including Tom Brokaw) and access is very difficult, not least since this section's deep pools and steep banks are difficult to impossible to reach even with Montana's generous stream access law. The best way to access this water is therefore by floating. This is a raft-only river, and is only floatable until sometime in late July or early August. Streamers and caddis are good bets from the time the river clears in mid-late June through late July, while hoppers are good choices later. The upper mainstem Boulder, above a waterfall, is mostly in National Forest and is paralleled by good roads, so access is easy. The brookies and rainbows here like attractor dry/dropper combinations and, in season, hoppers. Parks' Fly Shop does not guide the main Boulder.
The forks of Boulder, and there are a bunch of them, offer good small-stream/small-river fishing for a variety of species. Generally dry/dropper combos will work well, but the meadows of the upper West Fork hold some spooky cutthroats and browns that would rather have Green Drakes, PMDs, or terrestrials. Once in a blue moon we run walk trips with repeat clients on the upper West Fork. The other forks are also of interest to anglers, and they have fairly good access.
The Missouri River below Holter Dam vies with the Bighorn for the title of best tailwater trout river in Montana. Other websites can discuss this fishing in much more detail and with more accuracy than we can. Some of our contract outfitters guide on this water most of the season, and we'd be glad to send you their way or to set up a trip split between our area of operations and the trout water on the Missouri. Some excellent trout water is also found upstream of Holter, in the short tailwaters below Canyon Ferry Dam and Hauser Dam. Below the latter, spring and fall bring runs of very large rainbows run up from Upper Holter Lake. These fish average 16-24 inches, which is why we target them on our power boat trips, despite the long drive.. In the spring, try midges such as WD-40s, pink scuds, San Juan Worms, and egg patterns. In the fall, try streamers and egg patterns. Don't expect a lot of fish, but many of those you do catch will be over 20 inches.
Our other primary interest in the Missouri is carp. Though there are carp throughout the Missouri system, the best access is found from Canyon Ferry Reservoir up to Toston Dam. Public land near the town of Townsend, near the town of Toston, and for several miles below Toston Dam provide good foot access, while a float from Toston Dam to Toston or from Toston to York Island works for those who don't want to walk. The best tactic is to look for feeding carp, either by floating at midriver and watching the banks and foam eddies or stalking the banks on foot, then making a careful approach and dropping a crayfish imitation, grasshopper, cottonwood seed, hopper, caddis, or subdued nymph right in front of the targeted fish. Since this section of river is broad and often quite shallow, this bears a great deal of similarity to stalking bonefish on the flats. We have caught carp in less than a foot of water, and had "tailers" in slightly deeper water. We very occasionally get one of our clients to fish this water for carp with us, and we usually get several fish in the 5-15lb range. There are also some very large rainbows present yearround in this section, usually near the small cold springs that enter sporadically, as well as a few truly monstrous browns that run up from Canyon Ferry Reservoir in the fall.
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