A Guide's Guide to Fly Fishing in Yellowstone National Park
Heading to Yellowstone? Fly fishing expert Boone Tullett has some advice on when and where to go fly fishing.
The greater Yellowstone ecosystem is well known to be one of the most prolific fisheries in the lower 48 states. Most anglers who come to the area are seeking pristine waterways and trophy trout, and frankly, they have picked the perfect place to achieve those goals and even get that picture for Instagram.
However, there are a few things that will make your time fly fishing in and around Yellowstone National Park much more enjoyable. This article will give you some tips and suggestions about different effective fishing strategies, and tell you about some of the small streams and other waterways throughout the park. These waterways hold a variety of native species, as well as the invasive brook trout in the greater Yellowstone ecosystem and Yellowstone National Park.
Regulations and Permits
When you enter the park, you will want to check the Yellowstone fishing regulations provided by the national park at the entrance or at any ranger station. You can also find this information at local fly shops, where you’ll want to stop to purchase your Yellowstone National Park fishing permit. This permit does not require individuals over 12 years of age to have a valid fishing license in any state.
However, if you’re hoping to fish lower sections of the Madison or Gallatin Rivers, out past West Yellowstone, you will need a Montana state fishing license. These are available on the Montana Fish, Wildlife and Parks website.
Also keep in mind that as of 2019, felt soled wading shoes were also banned within the park in order to limit the spread of aquatic invasive species.
Once all the paperwork has been sorted out, you’ll want a good rod. For this area I find a 9-foot 5wt rod to be the most versatile for the many water styles which the park presents.
The next piece of kit you’ll want to acquire is some very heavy tippets as well as very light tippets. Some waterways hold large fish that demand a stouter line almost as much as the cautious native species that inhibit the smaller waterways.
Some folks can't leave the house without waders but during most of the summer I find them unbearable. I'm much more inclined to turn back if I forget my polarized sunnies than my waders during summertime in Yellowstone. On this note sunscreen is also good to have as well as a rain jacket for the opposite. For any off-piste fishing, insect repellent is a necessity if you want any chance of enjoying the fishing.
You will also want to invest in bear spray. On a particularly nice day last July, I was on my way to the upper meadows of Slough Creek and I passed five different bears in the first mile of the trail, including a mother with cubs. Fortunately this is a popular trail, and the bears generally keep to themselves. But sometimes they don’t, and it’s better to be prepared for this possibility.
While we’re on the subject of wildlife, if you plan on fishing near the Black Canyon region near Gardiner, you will want to bring a sturdy walking stick. There are rattlesnakes in this area, and sometimes the need to be flicked off the trail.
Know Your Hatches
In the world of fly fishing, there are several famous hatches. You might have heard of them. The Green Drake hatch on the Henry’s Fork. The PMD hatch on the Missouri. But none are more well known than the hatch of the salmon fly.
No, this is not a food source for salmon, as the name would suggest, although they do feed the large fish that western anglers quest for. The name comes from the bugs’ movement on the river, traveling up to 5 miles per day upstream in order to procreate and lay waterborne eggs, which will stay in the river as larvae for three or four years before shucking off their exoskeleton to start the process over again. This egg laying action is what most anglers attempt to duplicate.
In certain years, I’ve seen whole bridges transform from their usual motionless dull concrete color to a shifting black accompanied by a thick fog of these nearly thumb-sized insects. This is what drives fish - and fishermen - nuts. During the salmon fly hatch, the larger cutthroat trout, and even brown trout, will aggressively take large dry flies from the surface of the water. It goes without saying that this is one of the most exciting experiences that any angler can experience.
For this reason, with the salmon fly hatch comes a corresponding boat hatch. The word has been out since the ‘70s that fishing the salmon fly hatch is something worth planning for. These days when you head to the stone on a cool morning near the end of June, it is likely that by 9 am every parking lot throughout the Paradise Valley and beyond will be packed with excited anglers eager to try their hand during this legendary fishing season.
Make a Plan
You won’t find me at any of these lots. The hectic nature of fly-fisherman during this time of year can be alleviated by a bit of creative thinking, and if you are planning to head to the Yellowstone River in an attempt to take a picture for your wall there are a few things worth considering before you head out that can greatly increase your odds.
Let's talk about bugs. If you have done the smallest amount of reading about the salmon fly, you have probably read that timing is everything to have success during the hatch.
One of the first rivers that salmon flies begin to hatch on is the Firehole River. This is due to the hot springs that give this river its name. The large salmon fly nymphs don’t begin moving to shore until the water temperature is 55 degrees. The first inklings of the hatch begin near the last week of June and continue through mid-July, though it is possible to find salmon flies until the first week of August. Of course, this will vary slightly depending on the elevation and the water levels of the particular stream you are targeting. I could probably write a book about the minutia and variables that can and do affect these insects. But you aren’t an entomologist - you're an angler! And while some extra knowledge of the food sources of your target species is undoubtedly helpful it is not required to catch fish.
During the hatch, the fish gorge themselves on these large insects. They often overfeed and spend the next four to five days resting in deep slow water and not feeding. Because of this, the mere fact that big bugs are flying around does not mean that the fish will be biting. Even the afternoon of the first day of the salmon fly hatch can be too late during a heavy hatch year.
This is why whenever I see a salmon fly on the river, I will go upstream a few miles until I stop seeing the flyers and start seeing clean rocks. This means that the larvae haven't begun their migration to the shoreline and this is where I want to be, ahead of the hatch. The fish in this area are hungrier because this is, on the Yellowstone, the first major hatch since the Mother's Day caddis and in a big fast river like the Yellowstone, the high water levels can make it hard for trout to feed on these small bugs in the beginning of May. If you can time your day on the water to be two to four days before the salmon fly hatch and dredge the large stonefly nymphs, you will be surprised at your levels of productivity.
Get Ahead of the Hatch
Here’s how I fish ahead of the hatch. If you aren’t lucky enough to have meticulous journal entries dating back several years to track the beginning of the hatch exactly, there are some clues that will help you when you arrive on the scene.
The first thing that I look for when I get to the river not knowing when the bugs will start flying is a small pink flower on the pokey bushes along the bank. This flower is the desert rose, and it only blossoms when the high water ends. Once you see this flower, this harbinger of summer, you can bet that the river will begin to gradually decrease by around 1000 to 1500cfs per day until late July, when the river slows its rate of reduction to around 300-800cfs per day. Of course nothing in nature is perfectly true, but as a rule of thumb, I think these numbers are a good gauge.
The most important thing to note when you first see a desert rose is that salmon flies will be in the air within a week or two. If the flowers are beginning to wilt and fall off, then it's probably time to start dragging your salmon fly nymph near the bottom, because this is the time frame that the large larvae transition from the deeper, faster parts of the stream to the calm shore line in order to prepare for their trek onto the land. These larvae usually stage near the shore for a day or so, and when the larvae start moving, so do the fish.
Fishing Behind the Hatch
If you are not able to get ahead of the hatch, another of my preferred options is getting behind it. I usually spend the bulk of the salmon fly hatch avoiding the main sections that I love, and instead getting the pack out and looking upstream toward the many high alpine lakes that also hold very hungry fish that have just experienced ice off. Once the salmon fly hatch arrives on my water, I won't throw an imitation for at least three days after the bugs stop. Because the salmon flies move through in waves, there are often these lulls throughout the hatch and can help you find your timing on either end. If you miss a hatch, there is another hatch coming in a few days, usually.
In recent years the hatch has become more sporadic with bugs emerging out of sequence along the river. This is another reason that fishing the main hatch can be difficult. During this time, Yellowstone Lake can be a great place to fish for one of the nonnative fish species in the park, the lake trout. If you want to help the park restoration efforts, please kill all lake trout you manage to catch! A big wooly bugger under an indicator is a standby for still water fishing.
Places to Check Out
If you happen to be travelling to the region during the mid-summer months there are plenty of prolific fisheries that begin clearing up as the fishing season progresses. Here are some of my favorites.
If someone were to ask me the best place to fish inside Yellowstone Park would be Slough Creek. Yellowstone fly fishing expert Doc Knoll once said if there is a church of fly fishing, then Slough Creek is on the altar and Soda Butte Creek is the first pew. I agree wholeheartedly. Slough Creek provides anglers with technical sight fishing for large native cutthroat trout. This is no beginner brookie trip, and if you plan to fish in this area, be prepared for fickle fish. In all my years of fishing, this waterway is one of few places that absolutely requires a 6x tippet if you really want to have a productive day.
One of the best places to fish is the pocket water created by a short gradient before the creek pours into the Lamar River. This pocket water is excellent for nymphing pheasant tails and the occasional caddis pattern will induce a rise. As you progress to the top of the short canyon and enter the meadow, large Mormon cricket patterns and other terrestrials can entice the cruising fish into the deep pools. If you are hunting for really big fish you will want to approach low, occasionally crawling along the bank to get into position and using a beefy streamer pattern. Personally I fish an olive mini sex dungeon in the back of the deepest pools and cut banks along the meadow section.
The best time to fish this area is early in the day, as you will want to be heading home by 3pm, when the mosquitos and bears come out, making fishing difficult. Also, the drive to the North Entrance is much more pleasant in the daylight.
Another excellent waterway that has good fishing during July and August is the Yellowstone River itself, which boasts fantastic grasshopper fishing. Many folks see big water and big fish and start slapping the water with big bugs. If you do want to fish this style, I recommend sizing down to a 12 or even a 10 hopper. Personally I like the Letort style.
However, as tempting as surface eats are, never forget that terrestrials are only a supplement to a fish’s diet. They are more likely eating aquatic insects, which naturally occur at regular intervals during the day, such as caddis and smaller stoneflies, which hatch later than the salmon flies. The lower sections of the Yellowstone River hold rainbow trout, cutthroat, and brown trout, and all will rise to a proper drift and all can be quite sizable. These are Montana fish so they love to put on a show. I usually recommend 3x for most excursions on the Yellowstone.
As the season progresses into the fall months, fish hatcheries such as the very upper sections of the Madison River are very popular. Here, you will undoubtedly encounter other anglers chasing John Muirs' dream, as well as 30-inch brown trout that can be caught on large streamers and nymphs, including stoneflies and even royal prince nymphs.
This waterway can be slippery wading and has fish that have been caught several times, so it really pays to be the first fly the fish sees - wake up early! The strategy for the big browns is dredging your imitation through the deep pools behind the structure in the river.
For many locals in the know, the lower sections of the Gardiner River also hold surprisingly large numbers of spawning brown trout in the fall below the boiling river. It’s one of the few tributaries of the Yellowstone below The Grand Canyon of the Yellowstone for fish to run up and spawn. These large browns are both predatory and protective, so brown trout imitations are one of my favorites things to do for the fall spawn.
Another late summer option for the adventurous angler is an area known as the Thorofare area. This area is not to be taken lightly and should only be explored by experienced backpackers and those with some outdoor knowledge. This is the most remote area of Yellowstone and one of the most remote places in the country. For this reason if anything bad happens, help is very far away, if they are coming at all.
That being said, the Thorofare provides some of the best backcountry fishing in the world, with water holding native cutthroat trout in healthy numbers. The fish in this area are fortunate enough to not see many artificial insects and tend to be easier to fool. An Adams or a caddis is generally a good option for fishing this area, but refer to the local shops to learn more about the current hatches when you arrive at the park.
This article is certainly not gospel - it’s just a very short compilation of one guide’s tips and tricks for fishing these waters. But there is no substitute for a good guide! If you are more DIY, do more research and talk to people in the area, and remember to have fun and keep 'em’ wet!