Taimen (Hucho taimen) are an ancient and largest trout species on earth by far. However, this apex predator’s numbers and average size have dropped precipitously throughout their range in northern Mongolia and China, Siberia, and North Korea. A 2000-2004 study of the famous Eg and Uur Rivers revealed their taimen population was only half of its historic biomass. Taimen have a close relative in the Huchen or Danube Trout that is critically endangered. These morphs are virtually identical in all aspects with the Huchen possibly somewhat smaller. They’re completely separated geographically. Their ranges do not overlap and they can be identified easily from their range.

Taimen demand cold, clean, well oxygenated water. They’re powerful fish and like it in the white water or in ambush mode behind structure like boulders and blowdowns. Taimen are exceedingly territorial and this trait contributes to their downfall. Anglers can easily locate and target them in the exact same place. Once the largest of these territorial giants are harvested it is virtually impossible to replace them. With taimen, particularly the largest ones, every single fish matter and must be released immediately. Taimen are primarily piscivorous and will even cannibalize their own, but typically forage on lenok and grayling and even chinook salmon where their range overlap in the Pacific Amur Drainage. Taimen vigorously attack surface dwellers from insects, mice, lemmings, muskrats, ducks, and incredibly even beavers. Fortunately, they are a tough species and can survive multiple catching’s if handled properly.

Taimen are potamodromous and spend their entire life in fresh water. Typically, they over-winter in deep river water where they can be vulnerable to illegal harvesting. They are excessively territorial and will not stray but a few miles from their birthplace although occasionally will travel up to 60 miles according to tagging records. They’re usually somewhat solitary, but on occasion during exceptional feeding opportunities will hunt in packs, thus the appropriate “River Wolf” moniker. Fishing large rat/lemming patterns or swinging large streamers that imitate grayling, lenok, or taimen are techniques that work. However, we also took them on dries with orange Stimulator, Grasshopper, and orange Bomber patterns. We also took a few on nymphs fished with and without indicators. Stripping White Gartside Gurgler patterns in the white water also produced a few. Swinging sliders and poppers will also elicit strikes. Taimen are unsophisticated in virgin waters and as the apex predator are not readily put down by boat, oar or engine noise. However, they are warier where pressured and more stealth is required. The fly colors that produced best were: orange, yellow, red, black and white and combinations. For streamers we preferred a smaller trailer or stinger hook sized #1/0 rather than a lead hook of about #4/0. Quality hooks are a must with Owner or Gamakatsu good choices. We use RIO tapered leaders 12 – 20 lb. test in most conditions but use Big Nasty leaders when casting larger patterns.

Taimen spawn in spring, typically around late April to early June to coincide with the ice thaw. Taimen spawning is reliant on suitable water temperature. They seek out smaller tributary streams to spawn where water levels no more than five feet. The Mongolian fishing season opens June 15 and there’s typically good action then from all species as they are ravenous from the depravity of the harsh winter and the spawning activity. Taimen are powerfully built but are long and somewhat slender. Their colors vary with range and environment but mostly they have olive backs and flanks that are dotted with some brownish spots, they have a gaping maw and their signature orange/brown anal and caudal fins easily identify them. Like all salmonids, taimen are richly colored during their spawn and their flanks darken and the last part of their body, anal and caudal fins, turn dark red. Taimen are slow growing, sexually mature at about 5 – 7 years, are mostly piscivorous fish, long lived to possibly 55 years, and occupy both the Arctic and Pacific drainages. All taimen fishing by foreigners is fly fishing with a single barbless hook and catch and release. Natives can spin fish but with a single barbless hook.



Lenok (Brachymystax lenok) or Siberian Trout are the most ancient of the trout species, having evolved in the mid-Pleistocene about 110,000 to 450,000 years ago. There are two basic lenok morphs: the blunt nosed (Brachymystax turnensis) that inhabit the eastern part of its range in the Amur River watershed, and the sharp nosed lenok that inhabits the western and northern part of its range which we caught on our extended Mongolia excursion. Their range and habitat is similar to that of taimen in northern Mongolia, Siberia, Northern China and Korea. They demand pure, cold, oxygenated water like taimen, but prefer holding in slower water next to the fast current, back eddies and frog water.
Lenok are beautiful and look similar to brown trout but have an underbite and appear to have a touch of bonefish in their ancestry. They are silver to golden brown with many large, dark brown spots and show orange bands on their flanks. Their underbelly is yellowish, and their eyes large. Their tail and anal fins are brown/orange. During their spawn their body changes to a deep red with the dorsal and pectoral fins a cacophony of rainbow colors. They may look like browns but certainly are not as wily. They rarely, if ever, get the intense pressure browns do that make them progressively harder to catch.

The lenok range and habitat is cold, with winds from the Arctic, and their feeding season short. Consequently, they are somewhat obligate feeders. Surprisingly, little is known about the lenok life span, maximum size, behavior, and spawning. Interviews with our Flyshop partners and guides found agreement that they are slow growing, fairly long-lived and can potentially get very large – at least historically. The all-tackle IGFA record is 9 lb., but they are commonly reported to about 20 lbs. We heard reports that in years past they grew to almost 100 lbs. They attack dry flies, mice, Bombers, Chernobyl Ants, Stonefly, muddlers, and frog patterns on top readily, but primarily feed on small fish, nymphs, or taimen and salmon spawn. There are a lot of grasshoppers in their Mongolian range and using a grasshopper pattern as an indicator and a bead head nymph as a dropper is a deadly combination.



Grayling (Thymallus thymallus) are widespread in Mongolia with five distinct grayling morphs including: Arctic (Thymallus arcticus), Gold-tailed in the North, Mongolian or Giant Mongolian (Thymallus brevirostris) in the western Altai Mountains, Black or Hovsgol (Thymallus nigrescens) endemic to Lake Hovsgol, and Amur (Thymallus grubii) in the eastern Amur River drainage. In their specific range they’re abundant at certain times of the year as they congregate and are easy to catch. Mongolian grayling are omnivorous but sometimes also predatory. Their age, size, and weight vary greatly according to species genre, habitat, and ecological conditions. Several of their ranges are severely restricted and limited to a lake and or connected lake riverine system.

Grayling are wonderfully fun to catch with a light fly rod, especially on the surface. They hold in much deeper water than trout and will charge to the surface with great quickness to attack even the smallest of flies. There isn’t much in your fly box they won’t eat up to and including mice patterns on top and fairly large streamers proportionate to their body size down.

The diversity and size of Mongolia’s grayling is astonishing. There were three species in the watersheds we fished: mostly Gold-tailed but a few Arctic and Hovsgol. Two of Mongolia’s species really stand out, namely the Gold-tailed for their vivid and unusual coloring. There is virtually no recorded data on this morph. Secondarily is the Mongolian, for its great size, as it gets to over 85 cm. and rumored to even much larger, the largest on our planet. Dr. Robert Behnke, the renowned fisheries biologist, stated Arctic char attain a maximum length of 30” and a weight of 8.4 lbs. When we first saw a photo of a large Mongolian grayling specimen with its dorsal fin compressed it took us a while to recognize what it was.

In many types of water it is possible to take as many grayling as you want, on almost every cast. The same might have also been said about lenok and Amur trout but the grayling deny that opportunity as they are far more abundant and quicker to eat – sometimes immediately as your fly hits the water.


Tengis and Shishged Rivers

Tengis and Shishged Rivers are the ultimate fisherman’s challenge and is one of the best world-class fishing destination. The Rivers are 1250 km away from Ulaanbaatar City and known as the most remote and difficult place to reach for fishing. It runs through the western part of "East Taiga", the northern extension of the Darkhad Valley. The Shishged River starts from Tsagaa Nuur lake in the northernmost tip of Mongolia and then confluence with Tengis River. Then it gets to a very interesting river with fast currents and deep pools.


Eg River

The Eg river is the only outlet of huge Khovsgol lake, one of Mongolia´s top destinations. It starts as an alpine river with clear, slightly blue water and quite a few but easy rapids. It flows through some of the most beautiful landscape of Mongolia, wooded hills with rocky outcroppings and green lush meadows. The further it flows to the South, the drier the climate and the more the steppe takes over. As the crow flies, a good 400 km to the south, the Eg flows into the Selenge river and the Selenge finally into Lake Baikal.


Onon River

The Onon River rises on the northern slope of the Khan Khentii Mountain Range and flows 808 km to join the Shilka River in the Russian Federation. For its first 445 km the Onon flows through Mongolia. The Khyarkhan, Agats, Kheriin are small and medium sized rivers, that are tributaries and flow into the Onon in the proximity of our lodge. Our five rivers abound with many fish species, including taimen, lenok, Amur pike, grayling, trout and others.