he Yellowstone River runs for close to 700 miles from high up in the Absaroka Mountains in Yellowstone Park all the way it’s confluence with the Missouri River in North Dakota. The Yellowstone is the longest freestone river in the continental United States which means that has no major dams to regulate the flow in any way. Trout are in abundance as far down river as Billings. Below Billings it mainly becomes a warm water fishery. While it is a popular river to fish, the length of the Yellowstone means that it rarely over-pressured in any one stretch of river. Fishing from a drift boat or raft is the best way to access such a large river, but there are some good wade fishing opportunities to be had.
The best time to fish on the Yellowstone is either before run-off in Spring or after run-off from July through September. The Yellowstone River has a large spring run-off which usually starts sometime in early to mid May and runs until late June or early July. On years where there is lots of snow the run-off can go as late as mid-July. During this time there is not much fishing opportunities with the water being so high and muddy. It can also be very dangerous to try to wade or float during this high water time. You will have to use some big flashy nymphs and streamer if you are fishing when water is murky.
There are a variety of hatches that occur on the Yellowstone that make for some fantastic dry fly fishing. Late winter midge hatches kick off the dry fly season as the river wakes from its winter slumber. Baetis will hatch throughout spring, and this can make for some great dry fly action. Mothers Day Caddis will hatch sometime from late April until mid-May depending on weather. This can be a hard hatch to time because it often correlates with the start of run-off. Some years you can get a few days of caddis action before the water becomes too muddy. After run-off a good variety of hatches will make for plenty of dry fly fishing. Caddis, Pale Morning Duns, Golden Stones, Salmon Flies, and Yellow Sallies are the main hatches you will find in July. Fishing with terrestrials such as Grass Hopper, Ants and Beetles becomes good as the river drops and summer weather gets into full gear. Nymphing is the best way to catch trout when they aren’t eating on the surface. Larger stone fly nymphs trailed with smaller bead head soft hackle nymph droppers are very effective on the Yellowstone. Streamer fishing is great at times, especially during fall when the Brown Trout get in spawning mode. Fishing a sinking line with a large streamer will give you a chance at getting a real pig. There are a ton of whitefish in the Yellowstone and they love to eat small nymphs. When the trout fishing is slow you will often catch a pile of Whitefish on the smaller nymphs.
The river inside Yellowstone National Park is primarily a Cutthroat Trout fishery with some Rainbow Trout and lots of Mountain Whitefish. A Yellowstone Park fishing license is required to fish inside of the park. The river flows out of Yellowstone Lake through the Hayden Valley towards the Grand Canyon of the Yellowstone. This section has some large Cutthroat that migrate out of the lake, but unfortunately in recent years there has been a major decline in Yellowstone Lake Cutthroat. These fish are very picky and will require some patience and delicate casting to catch. Below the Lower Falls of the Yellowstone the river runs through the Grand Canyon of the Yellowstone which involves a very steep hike to access. Not too many people head down into the Grand Canyon because of the tough access. To be honest you can catch just as many fish in the Black Canyon of the Yellowstone. The Black Canyon starts below Tower Falls and runs down to the park boundary at Gardiner. This is my favorite stretch to fish in the park because of the abundant trout population and lack of fishing pressure. Dry fly fishing can be very easy here if you make the effort to hike into the Canyon. Some of the best Salmon Fly fishing around is to be had in the Black Canyon sometime around early July.
Below the Park boundary the river flows through Yankee Jim Canyon. This water is more for whitewater enthusiasts, but the fish can be easy to catch since fishing pressure is relatively low. There is mostly a mix of Rainbow and Cutthroat in this section. At Carbella access the river mellows out and flows through the Paradise Valley. This is a very beautiful stretch of river with scenic views of the Absaroka Mountains. The upper end of the valley still consists of mostly Rainbows and Cutthroat, and of course there are tons of Mountain Whitefish. Attractor dry and terrestrial fishing is amazing at times in the Paradise Valley. Although the fish may not be as big as in the lower river, you will often find their willingness to eat a dry fly more than makes up for the size.
Brown Trout start to become more abundant, and Cutthroat numbers thin out the closer to Livingston you go. Also you will find the fish get larger as you go lower down the valley. As the river approaches Livingston it becomes more braided into channels, and the floating gets a bit more challenging for the novice oarsman. Wade fishing in this area is good, as you can fish the side channels which are much easier to wade then the whole big river. There are some very large fish to be had from Livingston down to Big Timber. Dry fly fishing is not as reliable down here, but this is the place to be for chasing after larger fish. The river leaves the mountains below Livingston and flows through Montana high plains country. There are great views to be had of the Crazy, Absaroka and Beartooth Mountains. The river is more braided here, and there are a few rapids that can sneak up on you if you’re not looking out for them. There is a mix of good sized Rainbow and Brown Trout to catch down here. Nymphs and streamers are very effective down here, but don’t overlook dry flies on the lower river. Hatches are not as thick as up high, but these fish will still take the opportunity to eat a hopper or ant during summer.
During high water conditions on the Yellowstone most fish will be close to the banks. Fishing the protected soft water against the bank can be very productive, as most of the river will be to fast for trout to hold in. When the water levels drop you will find that fish will move more into the middle of the river. A common mistake that people make is pounding the banks during low water conditions. Fish will slide off into the deeper runs when the water along the banks becomes low and clear.
As you can see there are many options on the Yellowstone. It would take a book to thoroughly cover the river, but hopefully this gives some insight into fishing the Yellowstone. Each section offers distinctly different fishing opportunities. If you are looking for an easy float with great views, Cutthroat Trout and reliable dry fly fishing then try the Paradise Valley. If you like chasing big trout then head to Livingston or below. The Yellowstone is a wild river with powerful wild trout in abundance.