Here’s a link to an article on a Mongolia fly fishing expedition with Peter Mullet of Mongofly, amongst the team were Mikey Wier of Burl Productions, Brent Dawson of Warpath Flies, and Jeff Currier. Link the full pdf article and photos: 2008 Fly Fishing in Mongolia.

Confluence of Mongolia's Chuluut and Ider Rivers. Photo: JeffCurrier.com
Excerpt:
Our main quarry were taimen, basically the worlds largest trout. These beauties don’t come easy and we as a 6 person group landed about 45 of them in 3 weeks. Many of them topped 40″! Mikey Weir landed one of 50″! Being one that loves to catch ALL species, I also enjoyed fishing for lenok, grayling and pike. I managed a pike that measured nearly 40″ and weighed 16lb! An awesome fly rod pike from a river!
Our group was as good as the fishing itself. Mikey Wier, producer of the well loved fly fishing movie “Soul Fish”, Brent Dawson, talented creator of War Path Flys Co, and Peter Mullet of Mongofly, our trip host, leader and Mongolian fly fishing expert (10 trips to Mongolia!), were key to the trips success. They navigated us through this foreign land and provided tools of fly’s and knowledge to catch a taimen. Genevieve Villimizar and my great college pal and partner, Paul Cavanaugh, added to the group. Add in the Mongolian camp staff and Chinbat, and we couldn’t go wrong!
Mikey Wier releases a Taimen somewhere in Mongolia. Photo: JeffCurrier.com

