The Big Wood River's name comes from the many cottonwood trees that line the banks of the river. It is a nice freestone stream that has a good population of rainbow trout. The stream has several access point most of which are off of Utah Highway #75 which follows the river for most of its length. Fly fishing the Big Wood River is convenient and easy to do, but the
catching isn't always so easy.
The river headwaters start near Galena Summit in the Sawtooth Mountain Range. It flows between the Pioneer Mountains and the Boulder Mountains and Smoky Mountains before entering beautiful Sun Valley. Its North Fork enters the main river about ten miles north of Ketchum. Its East Fork, flowing from the
Pioneer Mountains, joins in on the flow below Ketchum at Gimlet. From Sun Valley the river flows into Wood River Valley and finally into Magic Reservoir.
Fly Fishing Big Wood River is affected by two things - the snow pack and irrigation needs. Irrigation for agricultural needs can drain the lower end of the stream of much of its water affecting the water temperatures and fishing. On wet years Where there is lots of rain and a deep snow pack, fishing remains good for the entire year. When there is a deep winter snow pack, the runoff can last until near the end of June.
The rainbows and brown trout in the Big Wood River have a lot of food to choose from and can be very picky at times. There's lots of aquatic insects and plenty of baitfish and sculpin. Mayflies, stoneflies and caddisflies are plentiful. Matching the hatch or what is about to hatch is often necessary if you expect much success.
The headwater sections of the river are quite different than the larger section that flows through the valley. Most of the upper part is fast, pocket water and on a rather steep decline with the exception of some meadow type areas with smooth flowing water. The lower section is more of a classic run, riffle and pool configuration.