General Fishing Information
Known to Mongolians as the “river wolf”, Taimen (Hucho Hucho Taimen) is exceptionally fierce and ferocious predators. As the world’s largest surviving salmonid, they are famous for feeding on large fish, ducks, mice, and even large prairie dogs. Anglers can expect several opportunities to hook taimen each day. That typically means you see the fish below the fly, behind the fly, or on top of the fly. Don’t be fooled, however: taimen fishing can be challenging, and in many ways, it is similar to steelhead fishing. While the ability to make long casts can be an advantage, it is certainly not a necessity, as many big taimen will strike within a boat-length of the rod tip. Patience and persistence are more important in this game.

Both the Onon and the Delger Rivers are home to incredibly healthy taimen populations. And due in part to the outfitter’s community-based conservation efforts and careful management program, the fishing has never been better. While this is an operation that catches and releases hundreds of taimen annually, it is important to note that taimen fishing is not easy. These fish are big, old and smart. Sometimes the river rewards with a double-digit day, and other times the fish can get very finicky. Taimen are the ultimate mega-trout – easily the world’s largest. They are beautiful fish, with stunning coloration and vibrant red tails. Mongolian taimen can live for at least 50 years and at times can reach 60 inches in length. Adult taimen caught on the fly typically measure between 30 and 40 inches. Anything over 40 inches (1 meter) is considered trophy class. Their main diet is smaller fish, and they will take well-presented streamers on a regular basis. When floating these rivers, it is not uncommon to see monster taimen exploding across the river in hot pursuit of a small and very frightened lenok. Often-times that desperate lenok will throw itself to the bank to escape the determined taimen. 
Given the chance, taimen will also feed on mice, gophers and ground squirrels that happen to fall into the river. And that means these behemoth trout will destroy – and we do mean destroy – top water flies. The privilege of connecting with a trout species unlike any other and the joy of safely releasing these huge fish back into the wild are things that make a trip to Mongolia so special.

These rivers are also home to impressive numbers of lenok and grayling, and anglers often net more than a dozen of these trout in a single day (usually on dry flies). When fishing in a taimen sanctuary, a sunny afternoon spent drifting hoppers to 20-inch trout is an incredible bonus. The lenok that are found throughout Mongolia is a beautiful fish, with silvery bodies, bright red bands, and black spots. These native trout feed aggressively on the surface throughout the summer and autumn. Their behavior reminds many anglers of cutthroat trout found throughout the Western US.

The two rivers that are fished and outfitted by Mongolia River Outfitters are situated 500 miles (800 kilometers) apart. Although each river offers a unique and quite different fishing experience, they both offer productive fisheries, spectacular scenery and waters that are exceptionally well-suited to fly fishing.
The Mongolian government has designated both locations as “taimen sanctuaries,” and no international angler may legally access these rivers without a permit secured through our outfitter. Together, these two rivers represent approximately four hundred miles of taimen habitat conserved in partnership with local communities.

Onon River  – Upper River Adventure
If there was one “classic” camping trip for Mongolia, this would be the one. Beautiful landscapes, fascinating culture, professional staff, exceptional ger camps, and world-class fishing. With these trips, a small group of up to eight anglers can explore nearly 80 miles of pristine river. Float through the world’s first taimen sanctuary, casting for taimen, lenok, and trout on a fresh stretch of river every day. Guests will move locations daily and stay in a well-appointed ger camp each evening. Each campsite along the river is uniquely peaceful, designed to reflect Mongolian traditions and integrate with the countryside’s natural surroundings. Each day’s float covers 10 to 15 miles (16-24 kilometers) of water, with a mid-day break for a hot shore lunch. The guides have fished this river for many years, and they will consistently put anglers into the best positions to present the fly. It’s quite an experience: standing tall in a drift boat while casting to the world’s largest trout. The river is the first in Mongolia to be legally designated as catch-and-release, fly-fishing only for international anglers. On the Onon River, you also have the opportunity to catch Amur Pike and Amur Trout.  These fish provide exciting opportunities to catch additional native species.  It is interesting to note that all the fish that are caught in Mongolia are native to the watersheds, and in fact, these are the same species that were present when Ghengis Khan ruled Mongolia.

Onon River  – Lower River Adventure
This beautiful and remote section of the Onon River offers anglers an itinerary that includes eight days of floating and fishing. As with the upper river float on the Onon, this section includes a portion of the world’s first taimen sanctuary, home to taimen, lenok, pike and trout. Stretching for nearly 100 miles, guests will fish fresh and new water each day. This trip is designed for those who don’t mind a bit of “roughing it” in order to journey down a one of the most remote rivers in the country. On this section, all anglers fish from ClackaCraft low profile drift boats or Headhunter Skiffs. Manufactured in the United States, Clackacrafts are fantastic fishing platforms. They have comfortable seats, solid casting braces, full-length rod storage, and plenty of dry storage for gear. These drift boats allow guides and anglers to fish the river quietly, efficiently and comfortably. Each day’s float covers 10 to 15 miles (16-24 kilometers) of water, with a mid-day break for a hot shore lunch.

Delger River – Canyon Float
Seven full days covering nearly one-hundred and sixty kilometers of epic taimen and trout water. The river is remote and difficult to access, offering pristine and secluded angling. That can only be accessed by boat. These trips begin in the forested mountain headwaters, and over the course of a week, the river carves its way through limestone and granite in a canyon that is flanked by spectacular cliffs and rock pinnacles.  There are very healthy taimen populations with fish over 50-inches encountered every season. When floating the Delger Canyon, anglers will fish out of inflatable NRS drift boats. These non-motorized craft are perfect for the task: quiet, stable, and ideal for two anglers and a guide. This is a beautiful, wild river, with variable flows and fishing conditions. All fishing on the Delger is catch/release, fly fishing only using single, barbless hooks.

Delger River – Headwaters Expeditionary Trip
With this amazing adventure, the outfitter packs the entire camp – boats and all – on to camels. Guests then travel deep into the wilderness for seven full days of wilderness fishing on incredible taimen waters. The guides call this place “The Temple,”and in this remote section of Mongolia, the river is extremely isolated and strikingly beautiful. Steep, forested walls frame the boulder-filled stream, creating one of the most protected fisheries on the planet. The Headwaters Expedition is about quality of fishing over quantity.  You can expect to fish these waters meticulously, quietly walking and wading while accompanied by a professional guide. There are some enormous fish in these waters.  When the river is clear, there are opportunities to sight fish for extremely large taimen in the 50-60-inch range.  The trout fishing on this section of river is also quite good. The total number of anglers is limited to four per expedition. Guests often combine a Headwaters Expedition with a Classic Canyon driftboat trip.  By linking both journeys, guests are able to fish for nearly two full weeks, exploring a new stretch of river almost every day.

Boats and Equipment
On both rivers, our outfitter uses non-motorized boats to reach a string of isolated, environmentally progressive, and very comfortable camps. Depending on the location and section of river, anglers will drift fish and float each day utilizing traditional American drift boats (Onon River), inflatable NRS drift boats ( Delger Canyon trip), or a combination of wading and rafts (Delger expeditionary trip). The typical situation has two anglers per boat fishing with one guide. While flies, tippet and leaders are included with each package, it is recommended that anglers bring all of their own fishing equipment, including rods, reels, lines, waders and boots. The typical taimen rod is a single-handed eight- or nine-weight, although some casters prefer a ten-weight for the larger, wind-resistant flies. Please refer to the Yellow Dog pre-trip planning book for detailed packing lists and equipment recommendations.

Catch and Release / Fly Fishing Only
The Onon River was the first in Mongolia to be legally designated catch-and-release, fly-fishing only for all international anglers. We insist that all clients practice catch-and-release fly-fishing using single, barbless hooks. It takes a taimen approximately seven years to reach sexual maturity, and a truly large fish can be 25 or 30 years old. Even in the healthiest of rivers, their population densities are not high. Treating these amazing animals with care and respect is of paramount importance