Mongolia Fishing Trip Report: Mongolia River Outfitters September 2025

Posted by bmcgeehan

Is there another progressive fishing and camping river trip on the planet that can upstage a Mongolian fly fishing adventure? I don’t think so. Where else in the world can you listen to elk and wolves howling at night and then switch gears to chase both the world’s largest trout and pike that regularly surpass 40” with some monsters over 50” caught every year?

Our 2025 hosted trip to fly fish in Mongolia on the Onon River in the wilds of northeastern Mongolia easily surpassed all expectations. I was very excited for this adventure as we would be floating a new section of the river that I hadn’t seen yet. The majority of the Lower River float travels through the Onan-Balj National Park. This remote region is just south of Siberia and the Russian border. Our trip was to spend 8 days progressively camping and floating over 100 miles of water. Exotic gamefish including taimen, amur trout, lenok and grayling would await.

The previous year with Mongolia River Outfitters we fished the upper most section of the Onon which was an amazing trip. The Lower River is even larger as more tributaries join. The landscape is similar to the reach we floated the year before with open planes, river canyons and timbered mountains. We have the river to ourselves on these trips with only 6 anglers per trip and our partner outfitter is the only permitted outfitter.

Mongolia River Outfitters runs an exceptionally well organized program with excellent communication, great fishing guides, and well-equipped camps run by their attentive camp teams. In the summer camp teams operate further west on the Delger river system and then in the fall they run 5 sets of trips on the Onon river. These programs are so special because the most fishing pressure these fisheries experience is 5 trips only per river section total over the entire year. Each section of river only gets fished 5 days out of the entire season!

Monster taimen in Mongolia — Giant taimen, which are the world's largest freshwater trout species, are often the reason guests book a trip to Mongolia. Although the taimen are definitely the show stoppers our trip to this remote and wild country provides an adventure that extends far beyond this legendary gamefish species.

Onon River Mongolia — The Onon River is the largest tributary of the mighty Amur River which runs to the Pacific Ocean. The river starts near the Siberian border and eventually flows into Russia which is just 7 miles beyond the takeout of the lower river float. Mongolia River Outfitters breaks the river into 3 segments. Each segment takes 8 days to float and fish. On this trip we floated the lower river which flows through a huge National Park.

River camping in Mongolia — On our trip we enjoyed a progressive river camping experience. Every day our camp was broken down and floated downriver to the next campsite using 5 large gear boats and 1 lunch raft.

Drift boat fishing in Mongolia — Fishing is done from Clackacraft drift boats. Trips are maxed out at 6 anglers with 3 fishing guides. Each reach of the river is only fished 5 times all year by MRO with over a week of rest in between. Talk about unpressured fish!

Getting There is Part of the Adventure
There are no direct flights from the United States to Ulaanbaatar, Mongolia’s capital. The most common route is a direct flight to Seoul, Korea followed by a 2.5 hour flight to “UB”. On this trip my 13 year old daughter Lily was along so we opted to fly through Tokyo, Japan to spend a few nights soaking up big city life. We opted to stop over in Japan for three extra nights to do a little touring.

The trip price includes the arrival night Ulaanbaatar. It is easy to add an extra night, which is what our group opted to do. Ulaanbaatar features a blend of past legacies of Soviet error architecture with the vibrant new growth of a thriving capital city. Mongolia is rich in natural resources and the country is investing in the capital city as new office and apartment buildings are actively being constructed. Arriving a day early allows for a tour of the city to see museums, cultural sights, and even some shopping for local cashmere clothing.

Our Mongolian wilderness fly fishing expedition truly began when our drivers met us in the early morning at the hotel. With them as drivers and tour guides we trekked across northeastern Mongolia. Along the way we took a quick stop at the impressive “Chinggis Kahn” statue. Almost half of all Mongolians live in UB and once you leave the city you realize just how vast and remote Mongolia is. While driving across the famed Mongolian Steppe you see herds of goats, sheep, cattle, horses, and camels on the open range. Mongolia by national decree allows most of the country’s landscape to be used by nomadic herders. This traditional way of life is still thriving and even in the most remote regions “ger” camps can be seen in the distance along with groupings of animal herds. A ger is a Mongolian yurt with thick felt walls covered in canvas. There are no fences on the pastures of the Steppe and the nomadic herders move their ger camps a few times of year to follow their animals.

After a long 12 hour drive we arrived at our first camp along the Onon River. Most of Mongolia River Outfitter's camps are ger camps and MRO sets up about 15 of these camps on the Upper and Middle sections of the river. We arrived in time for a filling and delicious dinner and afterwards some enjoyed some spectacular star gazing. Because of being so far from civilization, this area of Mongolia features some of the greatest star-gazing on the planet.

Mount Fuji near Tokyo — Mount Fuji just outside of Tokyo. We made a stopover in Japan on the way to Mongolia to do a little exploring.

Shibuya Crossing in Tokyo — Shibuya Crossing in the heart of Tokyo. I have tried to have each of our 4 kids join me on one of our hosted trips when they are in 8th grade and this was Lily's big year for adventure.

Ulaanbaatar Mongolia — A blend of the old and the new in the capital city of Ulaanbaatar. The city is just over 1.7 million residents which is about half of the entire country's population. There is a blend of modern new buildings, older soviet error structures, and some pre-Soviet structures.

A group of young monks at the Gandantegchinlen monastery. The Buddhist monastery was founded in 1809 and is the center of Buddhism in Mongolia.

The impressive Chinggis Kahn statue is en route to our fishing grounds and is always worth the stop.

Driving across the Mongolian Steppe — There are only a handful of paved roads across the country. Much of the travel is on dirt two tracks in land cruisers en route to camp.

Camels in Mongolia — We came across a few herds of free ranging Bactrian camels along the drive. Mongolia by law allows nomadic herding across the country. Herders move with animals and set up ger camps to follow their goats, sheep, cattle, camels. and horses across the famed grasslands of the Mongolian Steppe.

Mongolian horses are some of the hardiest in the world. Herds of horses can be found nearly anywhere you travel in Mongolia as they move freely across the Steppe. There are no fences or private property on the grasslands and life is much as it was during the times of Chinggis Kahn for the nomadic herders.

Onon-Balj National Park
The Onon-Balj National Park is in the northwestern corner of Mongolia just south of Siberia. This is the home of the legendary emperor Chinggis Kahn (sometimes referred to as Genghis Kahn in the West). The remote park is filled with lower elevation mountains and both the Onon and Balj rivers. Nearly our entire trip over the course of 8 days was spent inside of the park. This is an incredibly wild part of the country and almost every night of the trip we listened to wolves howling and the Maral stag (or Asian elk) bugling. Midway through our trip we watched one of the huge elk swim the length of the river. The Maral stag are much larger than the red dear in Europe and are very similar to our Rocky Mountain Elk here at home.

As we floated down the river the scenery changed and ranged from open valleys to tight canyons with towering cliffs. The mountains looked somewhat similar to those in Montana with a blend of timber and meadows. We arrived at the peak of fall colors and the aspens, larch, and cottonwoods were bright yellow while smaller shrubs were a fire red color.

Onan-Balj National Park Mongolia — The lower river trip on the Onon flows through the remote Onon-Balj National Park. This is the homeland of Ghengis Kahn (pronounced Chinggis Kahn in Mongolia). Spending day after day floating down the changing scenery is truly spectacular. Most evenings we listened to wolves howling and the Asian Elk (Maral Stag) bugling. During the day massive eagles soared overhead.

Large eagle in Mongolia — Multiple eagle species are regularly observed soaring overhead while floating the river.

Life in Camp
The MRO team has been running these remote river camps for well over a decade and they have it completely dialed in. There are only two programs in Mongolia for travelling anglers to experience taimen fishing in Mongolia and Montana Angler partners with both Mongolian fly fishing outfitters.

The taimen fishing licenses for non-residents are very limited and only 100 anglers per year are permitted to fish the river. With almost 300 miles of water on the Onon the river is broken up into three large reaches. Each reach takes 8 days to cover while progressively floating and camping down the river. On most of the river system the traditional ger tents are used for the client sleeping tents, kitchen tent, and lodge tent. These are set up for the entire season and remain in place while the bedding and kitchen equipment is floated from camp to camp every day.

On the lower section when floating through the Onon-Balj National Park the camps must be completely removed every night. In this reach large canvas teepes outfitted with rugs, cots, and sleeping bags are used. The cots are made up like beds with pillows and several cashmere blankets.

Two large toilet tents are set up each evening. There is also a shower tent complete with wood burning stove, hot water, and a battery operated pressurized shower head. The entire camp is broken down every day and moved down the river in 5 large gear boats. A 6th raft is used as the lunch boat and every day on the water we enjoyed a hot lunch that was grilled on a picturesque gravel bar.

Chef Katya was outstanding and our crew raved about the food each evening. Dinners were always a great part of the evening with guests and guides converging in the warm lodge wall tent heated by a wood burning stove. Mornings provided hot coffee, pancakes, eggs, and a variety of other hearty accompaniments before departing on the river.

I know just how much work it takes to operate river camps. I’ve spent over 30 years guiding and overseeing operations of our own river camps here in Montana on the Smith River and other backcountry waters. These are equipment intensive programs and there are lots of fine details required to pull them off seamlessly. The MRO camps are very well done with lots of attention to detail.

Ger camps in Mongolia — MRO uses traditional ger camps on most of the river except for inside the National Park. They have about 15 camps set up along the river. Each camp has 3 sleeping gers, a kitchen ger, and a dining ger. There is also a shower wall tent and two bathroom tents. Each ger is outfitted with a wood burning stove. On the upper reaches you float from ger camp to ger camp while bringing all of the food and kitchen gear along in rafts. On our first night we used one of the ger camps but later we used teepees as we moved into the national park.

Teepees in Mongolia — Once inside the national park our sleeping quarters were large canvas teepees. Every morning the teepees were broken down and moved in the gear rafts to the next camp.

Camping in the national park — Once inside the Onon-Balj National Park the tents need to come down every night so teepees are used. There are also two large wall tents for the kitchen and the dining tent along with a hot shower tent and bathroom tents. The huge amount of gear is transported down the river using 5 large gear rafts as well as 1 lunch boat raft.

Gear Boats in Mongolia — No one works harder than the gear team! Whether it is on our Smith River trips at home in Montana or on remote Mongolian rivers, the gear boaters are the unsung heroes!

Teepee in Mongolia inside — The teepees used inside the national park aren't quite as spacious as the ger camps uprriver but they are still pretty darn comfortable!

Morning coffee — A hot cup of coffee in the morning to get the day started!

Evenings in camp lit by solar lights while enjoying great food and great company. Every evening the fishing guides join at the dinner table. The meals are always hearty and very tasty. Nothing tastes better than a great camp dinner!

The Fishing
We enjoyed 8 full days of fishing on the trip. When you are camping on the river each day is maximized because just after breakfast the drift boats are a short walk away. Most of the fly fishing in Mongolia is done from comfortable Clackacraft drift boats. There is occasionally time to do a little wade fishing around camp or in a riffle at lunch to target trout and grayling. As good as the trout fishing for the native lenok and Amur trout can be, it is difficult to pass up chasing the massive predators that reside in the river--the taimen. One of the cool things about the middle and lower reaches of the Onon is the abundance of Amur pike. Both the taimen and pike will hit large streamers and most of our group enjoyed targeting the bigger species.

The best rods for this kind of fishing are 8, 9, or 10 weight rods. I prefer to have a floating line on one rod in order to throw surface patterns like large gurglers and poppers. On the streamer rods an intermediate sink tip is helpful. A variety of flies with large 3/0 or 5/0 hooks are preferred. Big taimen love big flies but they can also wear you out casting them all day so a nice balance is some mid-sized flies. With 8 days of fishing, endurance is a big part of the game!

For the amur trout, lenok, and grayling a 5 or 6 weight with floating line is the best option. The trout fishing isn’t that technical and a Montana dry-dropper rig is a perfect setup. Even with some aggressive amur trout over 20” prowling the riffles, they are still not enough to pull your desires away from the massive taimen and pike.

Mongolian taimen fly fishing — MA guest Paul Shibley sends a big streamer towards a productive current seam in search of taimen.

Big fish big flies — Big fish, big flies! With predators like taimen and pike roaming the river, large streamers and surface patterns like gurglers and poppers are the ticket.

Lily's first fish on a fly — Lily's first fish ever on a fly rod was this 34" Amur Pike on our first day on the river. Not a bad way to get started in the sport!

fly rods in Mongolia — Although we always bring along a 5 or 6 weight for trout fishing, most of the day is spent casting 8,9 or 10 weight rods for the larger taimen and pike. I personally like an 8 weight for surface patterns like gurglers and poppers and then a 9 or 10 weight for streamers matched with a cold water intermediate sink tip. A 9 weight is great for most of the streamers but a 10 weight comes in handy when fishing really massive musky style flies. We fish for 8 days so you definitely have to pace yourself and trying to cast the biggest flies can wear your arm out so you have to be selective both with your fly selection and also take some strategic breaks along the way.

Paul with a taimen — Although taimen over 50" are landed every season on the Onon (the river record is 59"), most fish are under 30". On all of our past trips we have landed at least one fish over 40' over the course of the week. Once they are over 30" you are really starting to get the 'big fish experience!" Paul's 38" beauty with guide Tsogo is a great taimen and everyone in our party enjoyed landing a fish in the mid to upper 30" range by the end of the week with a few 40" plus fish in the mix as well!

lunch on the river — Lunch on the river was a welcome break each day. The camp team and guides set up a comfortable setup and we enjoyed hot meals every afternoon. When you are casting big streamers for 8 days you find yourself looking forward to these welcome mid day breaks!

Chasing Taimen
The legendary taimen is definitely the star of the show on a fly fishing trip to Mongolia. The Onon River has a very healthy population of taimen with a few large taimen landed over 50” every season. The record taimen on the river for Mongolia River Outfitters is 59 ½”. Most of the taimen landed are in the high 20s. Any fish over 30” feels pretty darn big and the takes are spectacular. Taimen hold in classic trout water and love to move into fast water when hunting.

Like most large predators they don’t eat all day long every day. Some days it can be very quiet for hours at a time and then the river seems to wake up and you enjoy 2 hours of actively hunting fish. Taimen often wait and rest on large seams below islands and in large tailouts. Sometimes very large fish will be out in the middle of the river in fast water as they cruise and hunt the smaller trout species.

We hit the conditions just right on our trip. The first two days of fly fishing for taimen were a little slow in terms of activity as the river was still dropping and clearing after some heavy rains earlier the previous week. It also takes time for everyone to settle in and learn the nuances of strip-setting and having patience with these massive fish. Often taimen will hit a fly multiple times before getting hooked and it is imperative to keep the fly in the water and keep hitting an aggressive fish with strong strip sets. The excitement and adrenaline rush makes it hard to resist impulsively ripping the fly away. Nailing the strip set on a large taimen takes some practice. Eventually everyone figured out the magic sauce and by the end of the week our group of 6 had collectively landed over 100 taimen!

I managed to land my first taimen over 40” midway through the week while swinging flies in the main river channel while the guide slowly back rowed. I can still feel the hit today--while the fly was swinging in the current it felt like it hit a brick wall as a 42” monster taimen hooked up on the first swipe. After an epic fight and some great netting work by my guide, the fish was brought to hand.

By the end of the week we had collectively landed 4 taimen over 40”. I was fortunate to land a personal best 46” taimen that we spotted from across the river as we watched a large 18” lenok jump out of the water as a huge fish erupted in a toilet bowl flush as the monster taimen was chasing it. We quickly crossed the river and after the 3rd cast the big fish started following and slashing at the streamer I was fishing just below the surface. Eventually the huge fish made an aggressive grab and the line went tight; what a fish!

Later in the trip I had two more scenarios where huge taimen were actively hunting and producing large explosions at the water's surface. One of these fish was hunting in a shallow 2-foot deep riffle. For this fish we rigged up a gurgler and on the first cast the large 38” taimen crushed the surface pattern - amazing!

On our final day of fishing and late in the day as the sun had dropped we encountered another big fish that was pushing water as it hunted. This fish was actively moving along a fast bank and my guide, Soyu, had to work hard to keep the boat in place. While we were targeting that fish another huge taimen erupted in the heart of the run right out in the middle of the mighty Onon River. We crossed the river into a large eddy and back rowed to the top of the run. Soyu positioned the boat along the seam and worked hard on the oars to slow us down as I made long casts across the current. My arm was nearly dead after 8 days of fishing and I had a huge musky pattern tied onto the end of my line, but I knew there was no need to leave any gas left in the tank and I did my best to let ‘er rip. Within the next 30 minutes we landed two big fish including one more 44” monster. What a trip!

Mongolian Taimen — We landed over 100 taimen in the course of our week on the Onon but not all of them are river monsters. There are lots of different year classes. Lily's first taimen was a beautiful youngster that clocked in at a boastful 18":)

Taimen tail — One of the most distinctive features of the Siberian Taimen are their beautiful red tail fins.

monster taimen fishing — This was my first ever taimen over 40". It took multiple trips to Mongolia to make it happen but midway through the week my fly came to a jarring halt as this beast grabbed my streamer mid river. It is difficult to describe the adrenaline rush experienced when a truly large taimen attacks your fly!

42" taimen — Scott Drooger's 43" taimen was one of the 4 giant taimen we landed over the course of the week.

This was the largest taimen that made it to the net over the course of the week at 46". We were working a run when a huge explosion erupted at the surface on the far bank as a taimen chased an 18" lenok that jumped 3 feet out of the river to escape the predator. We immediately rowed across the river and positioned the drift boat at the top off a huge current seam. On my second cast the big taimen came to the surface and began slashing at the streamer. It hit the big musky pattern about 7 times before it finally hooked up - definitely the fish of a lifetime for me!

Taimen at sunset — My last fish of the trip. This was an amazing experience as the sun was setting on our final day of fishing. We spotted a big taimen pushing water as it corraled smaller trout along a bank. As we tried to intercept this fish while holding the boat in strong current, there was a massive eruption in strong current at the center of the river. A few minutes later we observed another huge boil. It seamed like several big taimen were working together and cruising up and down a large run while hunting. Soyu worked the oars like a madman and I made the longest casts I could to swing big flies across the river. We had two big fish hit and hooked them and fought them both! It was an amazing half hour of fishing. The first taimen was 38" and this larger beast measured in at 44". What an amazing way to end the trip!

The impressive Amur Pike
On previous trips further up the river system we had encountered an occasional pike. The upper reaches of the river is smaller and there are less of the back channels that pike love. One of the perks of the middle and lower reaches of the Onon is the increased presence of big pike. The Onon helps to form the Amur River just on the other side of the Russian border. The Amur River eventually forms the border between northeastern China and Russia as it makes its way to the Pacific Ocean. The Amur Pike is native to the Amur and its tributaries. The shape and behavior of the pike is similar to a Northern Pike, but the coloration is very different with light colored sides and dark spots.

Fly fishing for pike in Mongolia means to target the slow waters of the back channels as well as some of the slower moving currents in larger eddies. Sometimes we encountered pike while targeting taimen but generally the taimen preferred the strong currents of the main river while the pike were in slower waters. Often we would row up long back arms of the river to intentionally target big pike along banks or weed edges.

We all landed some nice pike in the 30” class. My largest pike of the trip came in right at 40”. These fish are very aggressive and hit the fly like a sledge hammer. Several even put on an aerial display with energetic jumps. Fly fishing for pike in Mongolia is not for faint-hearted anglers or Monday morning quarterbacks.

Amur pike in Mongolia — Taimen aren't the only river monsters found in the Onon. Huge Amur pike are an impressive game fish as well and are abundant on the lower reaches of the Onon. This unique species is only found in the Amur river and its tributaries. When on the river they tend to be found in slower moving eddies or huge backwater sloughs. The best pike habitat occurs in the regions where the river enters the plains and takes on a braided character with many side channels. Some of these abandoned slide channels for large sloughs with weed beds. Some days we would back row up into these sloughs and spend a few hours chasing these pike. This 40" monster was my biggest of the trip but we all landed several nice fish in the upper 30" range as well.

Mongolia river outfitters — The Onon flows through a blend of timbered mountains and canyons as well as the broad Mongolian Steppe. The best pike waters are found in the broader portions of the valley where side channels are more common along with sloughs. The pike like slower water than the taimen.

Amur trout, lenok, and grayling
It is quite a novelty to enjoy 8 days fishing where 18” trout are simply considered baitfish. The Onon River would be an amazing fishery if you solely targeted its trout species. But while fly fishing in Mongolia for taimen, there are plenty of other species to pursue. Grayling are very common in the Onon River but generally are small. Most days 6-11” grayling can be found rising in the shallow tail-outs of runs and can be targeted with smaller dry flies such as a size 16 adams. The lenok and Amur trout are occasionally caught on the huge streamers or big poppers we use for the taimen. The trout species love the swifter water along banks and classic dry dropper rigs are a good way to target them. The uppermost river stretches have excellent Amur trout habitat but on the Lower Onon most of the Amur trout are encountered near some of the tributaries that come in. Andy Maciejewski was lucky enough to land a large 22” Amur trout midway through our trip.

grayling in Mongolia — A small grayling holds in the shallow waters of a tail out. Grayling are abundant in the Onon although most are smaller and under 12". They readily take a dry fly and are often found rising in the shallow tail outs and riffles.

Andy with a beauty of an Amur trout. Like the Amur pike, the Amur trout is a unique species only found in the Amur river watershed. The Onon forms the Amur river shortly after our take out as it heads into Siberia where it eventually forms part of the Chinese and Russian border on its way to the Pacific Ocean. Amur trout can grow well over 20" and will aggressively hit topwater mouse patterns and gurglers. They love the swifter water along the banks of the canyon reaches of the river.

We’ll be back!
Unfortunately there is not enough time in a lifetime of fly fishing to sample all of the special fisheries on this earth. When planning hard earned fishing trips there is always a difficult choice to be made between exploring a new location vs. visiting a location that demands a return visit. Mongolia is definitely a place that is on my "favorites" list that I hope to continue making multiple return visits to in the future. I am a trout fisherman at heart and the opportunity to explore these incredibly remote and unpressured fisheries while casting to the world’s largest freshwater trout species is a very difficult scenario to upstage. As the world gets busier and busier it is so refreshing to be so completely unplugged.

There is something so incredibly magical about the slow pace of life as you spend day after day floating down the same river. When you toss in incredible guides, great food, and spectacular scenery it is no wonder that all of us had a perma-grin on the long drive back to Ulaanbaatar after the trip.

We will be returning to Mongolia to host trips in both 2026 and 2027.

Click here for details on our 2026 hosted trip!