New subspecies of Redband Trout in the Wood River Idaho

 As genetic methods continue to improve new discoveries regarding the diversity of our native trout have been coming to light at a surprising rate often challenging long held beliefs based on more traditional methods. This included the revelation that there are 25 distinct lineages of Cutthroat instead of the 14 that were once believed to exist (see here for more information) and the description of a new subspecies of Redband in the upper McCloud River of California (see here). 

Most recently, genetics work by Matthew Campbell at the Idaho Department of Fish and Game has revealed that the Wood River of central Idaho is home to a distinct lineage of Redband Trout that has managed to persist despite decades of hatchery Rainbow Trout introductions. The recent study published by Campbell et al. (here) shows that in that Wood River Redband are far more distinct than once believed and despite being part of the Columbia Basin today, the ancestors of the Wood River Redbands appear to have originated outside of the Columbia Basin. The Wood River Redbands aren't the only unique species in the basin either, which contains a unique species of Sculpin and genetics unique populations of Bridgelip Suckers and Mountain Whitefish as well. These unique populations are most likely explained by long isolation due to a nearly 200 foot high waterfall in the Malad River gorge in the lower part of the basin and possibly due to ancient connections between the Snake River and Klamath or Sacramento basins during the Pliocene.

The Wood River Redband Trout

Matthew Miller (the author of Fishing Through the Apocalypse: An Angler’s Adventures in the 21st Century) wrote an excellent article on the Wood River Redband Trout in Fly Fisherman Magazine, which can be found here: Discovering a “New” Redband Subspecies.