
Mongolia is one of those places where the photos never truly capture the magnificent grandeur of the location. When I try to explain the Mongolian landscape to those who haven't yet been, I ask them to imagine a location that looks like Montana with expansive big sky views but even fewer people. Mongolia is where there are no fences on the vast pastures of the steppe and marauding herds of livestock roam. Nomadic herding is the dominant way of life in most of the country and the white gers (think yurts) are prevalent even in the most remote valleys. This is still a place where you can float for three weeks on wild rivers and not see another boat; a land where the rivers are filled with piscatorial monsters measured in feet and not inches. On our 2024 hosted trip we teamed up with Mongolia River Outfitters to experience a 7 day float camping trip on the Onon River. The Onon starts near the border with Russian Siberia and then flows through about 200 miles of northern Mongolia before crossing back into Siberia where it eventually joins the Amur River.
The fishing on the Onon is a multi species experience. On our recent visit we consistently had opportunities for taimen, Amur trout, lennok, Amur pike, and grayling. Taimen are the largest trout species in the world with fish over 50” landed every season and some larger than 60” for a few lucky anglers over the years. Although the legendary taimen claimed the top billing, the other species also provided plenty of excitement on our trip. Our group enjoyed a spectacular experience with the MRO team and everyone had shots at large taimen approaching 50” with a few landed over 35”.


Where is Mongolia?
Mongolia is a completely landlocked country that is sandwiched between China to the south and Russia to the north (Siberia). The land area of Mongolia is about 20% of the total size of the Lower 48 states or approximately 4 times the size of Montana. Mongolia has one of the lowest population densities in the world. The total population is just over 3 million but most of its citizens are centered in or near the capital city of Ulaanbaatar. Once you drive an hour out of the city the population density is very sparse. On our trip, once we left the city we enjoyed sweeping big sky vistas and in about 11 hours of driving only encountered 3 or 4 small very small villages.
The largest economy in Mongolia is mining for coal or precious metals. On our trip we drove by one large mine about 1.5 hours outside of the city. Nomadic herding is still one of the dominant professions for Mongols outside of the city. Mongolia was once a satellite state of the former Soviet Union, but it is now a fully democratic market based economy.


The Nomadic Way of Live
About 40% of Mongolians live as nomadic herders. There is a Mongol saying: “there aren’t many Mongols, but we are everywhere.” When driving across the Mongolian steppe this saying seems to hold true. Even in the most remote areas that are hours from the nearest village, the traditional ger camps can be seen sparsely sprinkled in the distance. The gers are efficient mobile structures that the herders move a few times per season to follow their herds.
Mongolia’s vast natural pastures comprise the world’s largest contiguous area of common grazing land. Imagine remote areas of eastern Montana without a single barbed wire fence to be found. Animal herds often intermingle with cattle, cashmere goats, and sheep all traveling together. Only the horses seem to isolate themselves in their own unique herds.




The Onon River
Our recent trip was on the Onon River. We floated the headwater reaches of the river for 7 days and camped in ger camps along the way. When we launched the Clackacraft drift boats, we were in sight of the Russian border just a few miles to the north. The river flows through Mongolia for about 200 miles before it crosses the border back into Russian Siberia.
Mongolia River Outfitters breaks the Onon up into three distinct sections that each require 7 days of floating and fishing. Once the drift boats are launched on the upper most float, they remain in the river as the guides continuously move down from camp to camp. Anglers can join just for one 7 day trip to fish a single section, or can opt to combine 2 sections (or even 3) for a longer continuous floating adventure. The Onon is home to Siberian taimen, Amur trout, Amur pike, lennok and grayling. The pressure on the river is incredibly light. Each of the 7 day floating sections only sees a maximum of 6 anglers once per week over the 6 week fall season. This is the equivalent of 3 drift boats fishing the “Bird Float” in Paradise Valley just once per week and only 6 days the entire year! The Onon is a large river that starts at the headwaters similar in size to the Yellowstone River where it exits Yellowstone National Park and then grows to a river larger than the Upper Missouri River near Craig, Montana as tributaries join as you float downstream.




Fishing for the legendary Taimen
Taimen are the world’s largest trout species. Although there are historical anecdotes of taimen over 80” in length and 230lbs being landed by fisherman, any fish over 50” is considered a true trophy class. Although there are a handful of subspecies of taimen, the Siberian taimen found in northern Mongolia and Russia are the largest. In Mongolia the largest taimen caught on a fly have been just over 60” and 80 pounds or so.
To preserve these unique fish and create trophy taimen fisheries, the Mongolian government has put in place well thought-out management principles. There are only a handful of taimen permits that the government releases each year and it is required that anglers are guided. There are two operations in Mongolia that host international anglers and Montana Angler works with both! Mongolia River Outfitters and Sweetwater Taimen Camps are the only two outfitters for taimen in Mongolia. Mongolia River Outfitters (labeled Fish Mongolia for the summer operation) targets the Delger River in the summer months to the west and the Onon River to the east for the fall season. Sweetwater operates on the Eg and Ur River systems in the west. The Delger, Eg, and Ur Rivers flow north and the watershed eventually feeds Lake Baikal in Siberia. The Onon flows north and east where it forms the Amur River which eventually forms the Russia/China border before flowing into the Pacific.
Most of the taimen caught on our recent trip were in the 25-32” class. These fish produce heart pounding aggressive eats and are a blast to target and catch. The fish over 30” are less common but it seemed like we saw one or two in that size range on most days. The fish over 30” definitely made your heart skip a beat on the strikes. Having a fish over 3 feet long attack your fly in a trout river is not something we get to experience in Montana!
Our group of 4 anglers landed a total of 25 taimen during our trip. Montana Angler guest Bryan Schowalter’s 40-incher landed on a topwater gurgler pattern was the largest to the net. On our best day we moved over 20 taimen and landed 5 between the two angling boats. We landed taimen every day of the trip, although on any given day there was usually one person in the group that got blanked. We landed three taimen over 35” in the course of the week and had 3 other fish that either threw the hook, opened the hook, or broke off that we estimate were in the 45-50” range. Hooking a taimen is no easy task and a strong strip set is required. It seemed we managed to hook and land about one out of every 3 or 4 fish that hit the fly.






Taimen Tactics
We used a blend of 8 and 9 weight rods for the taimen. These were paired with either a floating line or an intermediate cold water streamer line. The guides provided flies which were similar to musky patterns with larger size 3/0 hooks. We used both streamers and surface patterns. For surface patterns we used a variety that included poppers, mouse patterns, gurglers, and Pole Dancers. Taimen were found in a variety of water during our multi-day camping and floating trip. We landed several fish on large seams, especially those below the convergence of two channels. Another favorite spot were long glides with medium current speeds and 3-4 foot deep water. Tail outs at the ends of long runs were another favorite holding position for taimen. We stopped to wade a few side channels, but most of our fishing was from the drift boats. When we were in water that looked productive such as seams the guides would either hold the boat in place or slowly back row down the run. This allowed us as anglers to cast and then strip the patterns back as they swung below the boat in the current.
We found that the taimen often did not get hooked on the first attack. It was imperative to avoid the “trout set” and keep the rod low and then be persistent with a firm strip set. Often the taimen would hit multiple times before they were hooked. This behavior was especially exciting when fishing surface patterns and a huge 40” fish would attack with its gaping jaws and massive red tail swiping and attacking at a fly on the surface. Taimen will often follow a fly during the retrieve in a similar fashion to musky. If we saw a taimen follow, it was important to leave the fly in the water and let it swing below the boat for a few strips, because taimen will often take the fly less than 10 feet from the boat after a follow. When a hunting fish was located we generally could get them to hit again even if it was after 15 or 20 more casts into the run. It seemed like once these fish were on the hunt they weren’t going to be denied a meal!







Amur Trout
Amur trout are a smaller relative of the taimen. These trout are impressive in their own right and we landed several over the course of the week between 15 and 24”. Generally we caught the Amur trout while targeting taimen, especially when fishing surface patterns like articulated mice or gurgles. Part of the adventure for the traveling angler in Mongolia is the opportunity to encounter some of these unique species.

Lennok
Lennok are another trout species found in Mongolia. They seemed to average slightly smaller than the Amur trout but were more abundant. Most of the lennok we landed were between 15 and 20 inches. Lennok love dry flies but will also hit subsurface patterns. We all brought trout rods for the trip and working water near the camps with a 5 weight was a welcome change of pace. I also spent some time fishing for lennok with a dry/dropper rig from the boats and had some success. During sparse hatches, lennok would often be seen rising along shallow glides on the river.

Grayling
Grayling were also abundant in the Onon. These were smaller with most in the 8-12” range. They were found in very shallow water like tail-outs and riffles. On many days we saw pods of grayling actively rising. A size 16 adams was a deadly option for these little dry fly loving fish.
Amur pike
The legendary Amur pike was high on my list of species to land on this trip and I had my chance on the third day when a large pike in a back eddy followed my Pole Dancer just below the surface on three consecutive casts. During each of these follows, the large pike tracked just inches below the surface for about 30 feet without ever sampling the goods. Amur pike are only found in stagnant water such as the back arms of sloughs formed by old channels of the river. We probably would have landed some pike if we chose to stop and row up into these sloughs, but the “taimen fever” tends to get in the way!
Equipment for Taimen in Mongolia
On this trip I brought a 9 weight with a cold water intermediate-sink streamer line, an 8 weight with a floating line, and a 5 weight with a floating line for Amur trout, lennok, and grayling. We used shorter 5-foot leaders of straight 30 or 40 pound tippet for the taimen. On the trout rods 9-foot 3X leaders paired with an attractor dry fly like a PMX or Chubby Chernobyl worked well. A dry dropper rig with a bead head Prince or Copper John also produced. When targeting grayling a smaller dry fly such as a size 16 Adams was a better choice.

The Camp Program at MRO
At Montana Angler we understand first-hand how daunting the logistics are when it comes to operating overnight river trips. Nothing in our program is more intensive on gear and staff than our 5 day Smith River expeditions. The progressive river camping program that Mongolia River Expeditions has developed is truly impressive.
MRO uses a combination of fixed ger camps and mobile wall tent camps. On the Delger system, and on most of the Onon River, the camps are seasonal ger camps. On the lower end of the Onon when it flows through a national park the gers are not permitted to be left in place. On this reach wall tents are used and packed-up each day to move to the next camp. Once on the river anglers progressively cover 8-15 miles of water each day. While fishing, the camp team breaks down the previous camp and moves to the next camp to set up before the anglers arrive.
MRO has 17 ger camps setup for the season along the Onon River. These are transported on dirt two tracks before the season begins and broken down at season end. Each ger camp consists of 3 gers for client tents, 1 kitchen ger, 1 dining and “lodge” ger, 1 shower ger, and 2 toilet wall tents. Every ger has a wood burning stove in it. The sleeping gers also have XL twin length platform beds. The gers have the traditional Mongolian decor including intricate tapestries. The camp team uses 3 large 18 foot rafts for transporting coolers, bedding, camp showers, chairs, and other equipment from camp to camp every day. There is also a lunch raft that sets up an elaborate lunch along a gravel bar every day where a hot lunch is prepared daily.
Once back in camp your overnight bags are waiting in your ger and there is a hanging area for waders and jackets. Appetizers, wine, and beer are available shortly after arriving in camp followed by an hour or two to relax, read a book, or do a little wade fishing. When the dinner bell rings everyone gathers in the lodge tent with the dining table for a hearty dinner. Each of the camps were set up in gorgeous remote areas right on the river. One night we listened to wolves howling in the middle of the night and then awoke to bugling red stag in the morning. Meals were excellent and always accompanied with a choice of sodas, red and white wines, or local beers. Fresh salads were an option each night along with a variety of local meals including dumplings and even a Korean themed night. All three of our fishing guides (Fabien, Marcello and Toga) joined us as hosts at every meal. The evenings in camp are always part of the experience and a great time to recap the day's adventures along the glowing warmth of the crackling fire in the wood burning stove.















Travel Details
A trip to Mongolia requires a reasonable time commitment both for the experience on the river as well as the travel time to get there and back. Anglers should plan for about 12 days of total travel. The most common route is to take an overnight flight to Seoul, Korea. Because you are crossing the international date line you land 2 calendar days after departing (even though you just spend one night on the plane). From the US the flight time is about 12-14 hours depending on where you leave from. From Seoul you then take a 3 hour connection direct to Ulaanbaatar. If you fly Delta or Korean airlines you can book it all one one ticket as they are Skyteam partners.
Upon landing in Ulaanbaatar the local ground concierge team was there to pick us up and transfer us to our hotel in the downtown area. The package with MRO includes one night hotel before and after in the capital city. We all opted to arrive one night early to tour the city before the transfer day to the river. It was easy to add the extra night and just pay the hotel directly a nominal fee for the add on. The transfer to the river is an overland adventure that takes about 12 hours. The vehicles are nice 4 wheel drive SUVs and we had 2 guests per vehicle for the ride. The first 2 hours are on pavement and the rest are on dirt roads. The two tracks aren’t rocky and even show up as highways on the local maps. These roads follow ancient travel corridors across the Mongolia steppe pastureland and are relatively smooth with just a few stream crossings along the way. The drive helps you to appreciate just how vast the country is with a very low population density. As we traveled we saw the nomadic gers and small flocks of sheep, goats, cattle, and horses sprinkled across the vast landscape.
On the way home we left our last camp after breakfast and made the long ground journey back to the city. We spent one more night at the local hotel and then flew out in the early afternoon the next day. When flying back to the states you now gain a day so even with the overnight flight we landed the same day we departed thanks to crossing the International date line.




Optional Extensions in Ulaanbaatar or Seoul
On this trip all of our group opted to spend one extra day in Ulaanbaatar to see some of the local sights. Our hotel was in the heart of the city center area and near several restaurants. The next morning our local guide Ganna met us to visit some of the sights in the area including the main parliamentary square and outdoor market, the National museum, a natural history museum and a local Buddhist monastery.
I also opted for an additional en route night to layover in Seoul, Korea and had an afternoon and most of the next day to tour the city and enjoy some great Korean barbecue restaurants.




How to join future trip opportunities to Mongolia
Our return hosted trip scheduled for September of 2025 is already full. We will be scheduling a 2026 trip soon (let us know if you are interested!). We are also happy to help you secure prime dates on other weeks and assist in the travel planning and organizing the transfers and concierge service in Ulaanbaatar either for the mid summer trips or the fall season.