PART 2: Mastering Fly Fishing on the Firehole River – Geothermal Waters, Top Hatches, and Expert Advice for Success
Emily Disbennett contributed to this article.
The Firehole River is one of the most unique and famous fly fishing rivers in the world. It offers an otherworldly blend of wild trout, geothermal features, and scenic beauty you have to experience to truly understand.
But fly fishing in this river also requires a thoughtful approach, as its environment and trout behavior differ from many other rivers in the region.
This article draws on advice from local fly shops like Blue Ribbon Flies, Madison River Outfitters, and additional sources from West Yellowstone. We'll also pull from our club members' experience, several of whom visited the Firehole on the last leg of our Montana outing in June.
The combined insight offers you detailed guidance and localized tips. Make the most of your next trip to the Firehole River, as well as rivers connected to this system throughout the region, in a national park that was initially marketed as "wonderland."
Overview and Unique Characteristics of Fly Fishing Firehole River
Yellowstone was established as the first national park by President Ulysses S. Grant on March 1, 1872. The mystique and grandeur of the setting make it easy to see why.
Its warm waters are the result of geothermal activity, creating a unique environment in which to fish, but also some additional challenges.
The Firehole River runs through the heart of Yellowstone, winding its way past geysers, hot springs, and fumaroles, through northwest Wyoming. Its waters are notably warmer than other nearby rivers, especially during the summer, often reaching temperatures that cause trout to become lethargic or seek cooler areas.
According to Yellowstone Fly Fishing Guides, the river’s insect life is also notably abundant, featuring prolific hatches of caddisflies, mayflies, and stoneflies.
What makes fishing the Firehole particularly interesting is the sight of trout rising amidst the steam of thermal features—a scene that blends the wonders of nature with a fly fishing experience like no other.
Mayflies swarm during a sizable hatch just outside Yellowstone on the Madison River. | Ryan May
A geothermal heated fishery
The geothermal action in Yellowstone, and especially within the Firehole River, throws a serious curveball at local fish and plant life. The river gets a constant flow of warm water from the park’s thermal features, making it kind of like a hot tub for fish during the winter.
Brown and rainbow trout can hang out, feed, and grow a bit faster in the colder months. But when summer rolls around and water temps spike, these same fish hit a wall. They get stressed and start bailing for cooler tributaries.
If you’re wondering why some trout in the Firehole look a little dull compared to their cold-water cousins, it’s because the heat also messes with their pigmentation, making their colors less intense.
On the flip side, the warm water and rich minerals create an all-you-can-eat buffet for algae and plants. Aquatic plants grow thick, feeding on the extra silica and nutrients in the water. Periphyton—tiny algae that grow on everything from rocks to leaves—thrive in these mineral-rich conditions, as long as the current doesn’t rip them off.
But when the water is too warm or too full of nutrients, it can lead to plant growth that clogs up oxygen levels and makes life tough for the fish trying to hang in there.
“I got to Montana on June 12th. Sunny and warm. Set up camp at Bakers Hole north of West Yellowstone. Hung out, tied some flies and met up with a friend.
“Took a drive into the park where we saw a moose near Norris during a snowstorm. Also, a black bear and two cubs near the Lamar Valley.
“Did a little bank fishing near the campground but no luck. A river otter was intent on catching our fish.”
- Irene Mitchell, Membership Committee
Yellowstone’s geothermal energy creates a cool, but tricky, ecosystem and a fishery you won’t find in any other river system. Everything living there—fish, plants, bugs—has to roll with the punches. It’s a constant game of adaptation, and only the toughest make it work year-round.
But that doesn’t make it a year-round fishery.
Best Seasons and Timing
The ideal time to fish the Firehole River is from mid-May to late June, before the waters warm too much. Local guides emphasize that once water temperatures exceed 70°F (21°C), it’s best to stop fishing to avoid stressing the trout.
Early mornings and late afternoons tend to be the most productive times, particularly during cooler weather.
As Firehole River expert Craig Mathews of Blue Ribbon Flies recommends, anglers should watch for hatches of Baetis (Blue-Winged Olives) and PMDs (Pale Morning Duns) during the spring and early summer.
These hatches bring trout to the surface, offering excellent dry fly fishing opportunities. The river also has a strong caddisfly population, and emergers are particularly effective when fish are sipping just below the surface.
“[I was] so excited to take Jeremy and Rolf to share one of my favorite places. We went around the whole loop. Firehole River, geysers, hot pots. Stopped to see Old Faithful and waterfalls.
“We were lucky to see a black bear and a grizzly along with a bunch of bison. Great day in the park.”
-Irene Mitchell, Membership Committee
Techniques for Success
Fishing the Firehole requires a light touch and a keen eye for rising fish. Since much of the river runs through open meadows, wind can be a factor. This makes accurate casting an important skill.
When fishing dry flies, a 9-foot leader tapered to 5X or 6X is best for presenting small flies delicately.
When fishing subsurface, swinging soft hackles downstream can be one of the most productive methods. As local guide services emphasize, this technique is especially effective when trout are feeding on emerging insects or during times when hatches are sporadic.
To achieve the best drift, cast slightly upstream and across. Then let the fly swing downstream in the current, mending your line when necessary to maximize the drift. The natural motion of the fly mimics an insect rising to the surface, often triggering aggressive strikes from trout.
Nymphing can also be effective, particularly in deeper sections or when fish aren’t feeding on the surface. The guides at Madison River Outfitters suggest using small beadhead nymphs like the Pheasant Tail or Zebra Midge under an indicator, particularly when there are no visible surface rises.
Best fishing strategy is stealth
Stealth is essential on the Firehole. The fish swimming around in its clear, highly pressured waters can be quite spooky, particularly in low-flow sections.
But being stealthy isn’t always easy. Whether you're casting on the Firehole or downstream in the Madison, local guides and respected sources like Orvis emphasize subtlety. It can be the difference between a successful day and a fishless one.
Here are seven tips to fine-tune your fly fishing stealth tactics for the Firehole River:
Tip 1: Stay low and move slowly.
Trout, particularly in clear waters like those found in the Firehole and Madison rivers, are highly attuned to movements above the water. Guides in the region suggest crouching or even kneeling when approaching the water. This reduces your profile, making you less of a threat. Always move slowly and deliberately—fish can pick up on sudden, jerky movements.
Tip 2: Use natural cover.
Leverage whatever natural cover is available. Trees, rocks, or even streamside grass can help you stay hidden. As many of the local guides will tell you, fishing the Madison River near Hebgen Lake often requires using the environment to your advantage, especially when targeting wary trout. Blend in with your surroundings to remain unseen.
Tip 3: Quiet your casting.
On waters like the Firehole River, where geothermal activity already causes some disturbance, the challenge is to not add more with sloppy casting. The fish in these warmer, mineral-rich waters are already on high alert.
Keep false casting to a minimum. When you do cast, make it as delicate as possible. Noisy presentations can send trout bolting, so focus on delivering your fly with a soft landing.
Tip 4: Watch your step.
The volcanic activity around the Firehole River keeps the water relatively clear. Any disturbance in the water can signal danger to wary fish. Yellowstone’s fishing regulations recommend that you wade slow and quiet.
Throughout much of this region, guides will tell you to avoid wading altogether if possible. If you must get in the water, shuffle your feet slowly and avoid kicking up sediment.
Tip 5: Blend in with Earth tones.
Wearing bright colors is like putting a neon sign over your head. As you can see in the images included with this article, muted earth tones like greens, browns, and grays allow you to more easily blend in with your surroundings.
It's not about camo—it’s about minimizing your visibility in an environment where fish are used to natural, subdued tones.
Tip 6: Play the light.
Managing light is crucial. Fish can spot your shadow or reflection easily in clear water. Keep the sun in front of you to avoid casting a shadow over the area into which you’re hoping to deliver your fly.
If you’re lucky enough to fish on a cloudy day, you’re in the sweet spot for stealth! Light is diffused and shadows are minimal.
Tip 7: Perfect your soft presentations.
In the Firehole River, fish see everything from hatches to tourist’s taking selfies next to bison. So even the smallest disturbances matter. This makes soft, controlled casts that minimize splash critical to your success here. When your leader and fly land softly, you have a much better chance of getting that take.
Gear Recommendations for the Firehole
Due to the smaller size of the trout and the need for delicate presentations, a 4-weight or 5-weight rod is ideal for fishing the Firehole River.
A 9-foot rod gives you the versatility to cast dry flies, nymphs, and soft hackles, while maintaining the finesse required for subtle presentations. Floating lines are standard, and leaders should be tapered to 9 feet with tippets in the 5X to 6X range.
For anglers who prefer fishing subsurface, having a few small split shots and indicators on hand can make the difference when nymphing.
Recommended Fly Patterns
Matching the hatch is critical on the Firehole River, and local fly shops are invaluable for selecting the pattern du jour. For dry fly fishing, the top choices include:
Baetis (Blue-Winged Olives): Parachute BWO in sizes 16-20
PMDs (Pale Morning Duns): Sparkle Dun or CDC Comparadun in sizes 16-18
Caddisflies: Elk Hair Caddis in tan or olive (sizes 14-16) and X-Caddis (sizes 16-18)
Soft Hackles: Partridge and Orange, Pheasant Tail Soft Hackle in sizes 16-18
Soft hackle flies are incredibly effective on the Firehole, as noted by the guides at Madison River Outfitters. Swinging soft hackles through riffles and runs imitates emerging insects, and trout are often quick to strike these patterns in the current.
Craig Mathews of Blue Ribbon is also a strong advocate for using soft hackles, especially during caddis hatches or when fish are feeding just under the surface.
Do you still need waders?
The water in the Firehole is often warmer than other rivers in the park. However, waders may add some additional comfort on the colder mornings depending on which section of the river you’re working.
That said, at least one of our club members wet waded in shorts all day in the Madison River, well downstream of the Firehole. So it all depends on your desired level of comfort.
Challenges and Conservation
Fishing the Firehole River presents some unique challenges due to its geothermal influence. The warm water is part of the river’s allure. But it also means that anglers need to be especially mindful of trout health.
Once water temperatures rise above 70°F, it’s important to stop fishing. Trout become stressed and are far less likely to survive after being caught and released in these conditions. As a result, the best fishing typically occurs in May and June, or during cool weather periods.
Local conservation efforts by organizations such as the Yellowstone Park Foundation and Trout Unlimited are essential in maintaining the river’s delicate balance. Both groups emphasize the importance of respecting the park’s regulations, practicing catch-and-release, and using barbless hooks to reduce harm to the fish.
Yet each organization goes about it with a slightly different focus.
Yellowstone Park Foundation
The Yellowstone Park Foundation (now part of Yellowstone Forever) has launched several conservation initiatives aimed at protecting the park’s rivers, including the Firehole.
Their Yellowstone Cutthroat Trout Conservation Project focuses on restoring native fish species to their historical watersheds and protecting critical habitats in the park. This effort ensures that the ecosystem, which includes the Firehole’s native trout population, remains balanced despite pressures from tourism and environmental change.
Another key initiative is their Aquatic Habitat Restoration program. This program actively restores degraded riverbanks, improves fish passage, and monitors water quality to mitigate the effects of increasing visitor numbers and rising water temperatures.
By enhancing habitat resilience, the program aims to protect sensitive areas of the Firehole River, which are especially vulnerable to human impact due to their proximity to geothermal features.
Trout Unlimited
Trout Unlimited has been a leader in advocating for sustainable fishing practices and habitat protection across the Yellowstone region. Their Yellowstone River Headwaters Home Rivers Initiative works to restore and protect cold-water fisheries in the park, including the Firehole.
One of their core strategies is to promote temperature-based fishing regulations. Trout Unlimited educates anglers about the dangers of fishing in water temperatures above 70°F, when trout are most vulnerable to stress. They also advocate for seasonal fishing closures on the Firehole during peak summer months, ensuring trout populations can recover.
Another important Trout Unlimited initiative is the Yellowstone Native Fish Conservation project, which helps safeguard native species, improve fish passage, and protect aquatic habitats.
On the Firehole, they focus on preserving riparian zones. These areas are pivotal for maintaining water quality and cooling stream temperatures to maintain the river's natural balance.
Where to fish when it’s too warm on the Firehole
The Firehole isn’t the only unique fishery in West Yellowstone. It merges with the Gibbon River to form the Madison River at Madison Junction, creating another fishery that can easily be wet waded in warmer months and be just as productive.
If you don’t want to wade or simply want to cover the most water possible, any number of guide services in the area offer floats down the river. They range from half days to full days and often provide lunch.
Given the water temperatures in late June, club members were unable to fish the Firehole River on this trip. But with the help of a reliable guide that we’ve used for years, we all caught fish.
“Tuesday was my turn to float. Finally, I got my fish. I will definitely go with Dave (Evans) again.”
-Irene Mitchell, Membership Committee
Fishing the Firehole River: Checklist of Essential Information
Fishing the Firehole River within Yellowstone National Park requires specific permits, knowledge of park regulations, and awareness of access points. Here's everything you need to know before planning your trip…
Park Access and Fees
To fish the Firehole River, you must first enter Yellowstone National Park, which requires an entrance fee:
Private Vehicle: $35 for a 7-day pass
Motorcycle: $30 for a 7-day pass
Individual (on foot or bicycle): $20 for a 7-day pass
Annual Yellowstone Pass: $70 for unlimited access for one year
Fees can be paid at park entrances or online via the National Park Service (NPS) website: www.nps.gov/yell/planyourvisit/fees.htm. Yellowstone Park is open year-round, but fishing is typically allowed from the Saturday of Memorial Day weekend through the first Sunday in November.
Fishing License and Permits
In addition to the park entrance fee, anglers must purchase a Yellowstone National Park Fishing Permit. No state fishing license is required, but park permits must be obtained:
3-day Permit: $40
7-day Permit: $55
Season Permit: $75
Permits can be purchased online at www.recreation.gov/activitypass/253423/ or in person at various visitor centers, ranger stations, and general stores within the park.
Regulations
Yellowstone National Park has specific fishing regulations, including:
Barbless Hooks: Only barbless hooks are permitted to reduce fish injury.
Catch-and-Release: Mandatory for native species, including cutthroat trout. You may keep certain non-native fish, but always consult current park regulations.
Visit www.nps.gov/yell/planyourvisit/fishing.htm for a complete guide to the rules.
Access Points and Parking
The Firehole River can be accessed from various points along the park’s road system:
Firehole Canyon Drive: A scenic route along the river with multiple pull-offs for parking. Early morning or late evening visits are recommended to avoid crowds.
Midway Geyser Basin: Located close to major geothermal features, this area provides access to the Firehole; but be mindful of fragile environments.
Madison Junction: Easily accessible near the junction of the Firehole and Gibbon Rivers, with parking available at designated lots.
Estimated Costs
Here’s a breakdown of estimated costs for a day of fishing on the Firehole River:
Park Entrance (Private Vehicle): $35 (valid for 7 days)
Yellowstone Fishing Permit (3-day): $40
Parking: Free within designated areas
Fishing Gear (rentals available in West Yellowstone): $50-$75/day (rod, waders, flies)
Additional Costs: Food, beverages, and potential guide services (rates typically range from $400-$600 for a full day)
Guided Fishing and Gear Rentals
If you prefer to fish with an experienced guide or need gear, several outfitters near the park offer services:
Blue Ribbon Flies (West Yellowstone, MT): Highly rated for guided trips and gear rentals. Contact Info – Website: blueribbonflies.com | Phone: (406) 646-7642
Madison River Outfitters (West Yellowstone, MT): Offers guided fishing trips and full gear rental packages. Contact Info – Website: madisonriveroutfitters.com | Phone: (406) 646-9644
Other Important Tips
Bear Spray: Always carry bear spray when venturing into the park's backcountry areas.
Weather: Be prepared for rapidly changing weather conditions in Yellowstone, even in summer.
For more detailed information, visit www.nps.gov/yell/planyourvisit/fishing.htm or contact the Visitor Information Line at (307) 344-7381.
Final Thoughts
Fly fishing the Firehole River in Yellowstone National Park is a unique experience that combines the beauty of the park’s geothermal features with the thrill of catching wild trout. With its abundant insect life, crystal-clear waters, and diverse fishing opportunities, the Firehole provides challenges and rewards for anglers of all skill levels.
As always, consult local fly shops like Blue Ribbon Flies and Madison River Outfitters for up-to-date fishing reports and fly recommendations before heading out. And remember to respect the fragile ecosystem of this iconic river.
By following these tips and using the recommended techniques, you can enjoy a memorable fly fishing adventure on the Firehole River, casting to rising trout in one of the most awe-inspiring landscapes in the world.
Check back on November 8 for the final installment in this series, just in time for fly tying season, PART 3: Essential Fly Patterns for Hebgen Lake, and the Madison and Firehole Rivers: Tying Recipes, Step-by-Step Videos, and Pro Tips.
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