Lower Blackfoot River

Lower Blackfoot River

As offered earlier in these articles describing regional fishing locations, the Blackfoot River varies in character from a classic meadow stream in upper reaches to being confined to a steep canyon in lower reaches.  Here deep holes punctuate the abundant riffles and runs. Most of this canyon reach is below Blackfoot River Reservoir, and water management practices there make for very seasonal best fishing in the river below.  Here the river (but not above the reservoir where a July 1 opening applies) is currently open during the catch and release season as well as the general season. Fishing can be good during the catch and release season as long as water flow remains low and flow constant.  However when the irrigation season begins, flows can vary widely through being subject to irrigation demands in the Snake River Plain below.  This variation impacts fishing success the same as changing flows out of Palisades Dam on the South Fork or Island Park Dam on the Henry’s Fork immediately below.  Nevertheless some success can be had, and the summer season will see drift boats and such on the reach from below the dam to Morgan Bridge.   Below this point there are no practical boat launch facilities except with difficulty at the Trail Creek Bridge and campground.  Below this location the river gradient increases steeply to the point that even kayakers avoid certain sections.  Access for fishing is also limited here until the river enters the Snake River Plain.  So irrigation water and terrain limit fishing on the lower river.  Below the Trail Creek bridge and campground the south bank of the river is on the Fort Hall Indian Reservation and therefore subject to reservation access regulations. Also as the river approaches the Snake River Plain increasing private land limits access, although the angler who stays within the high water level is legal.

Yellowstone cutthroat are the native inhabitants here and make up the bulk of salmonid population. Rainbow trout were introduced into the reservoir decades ago, and escapees are  in the river below.  Brush Creek features stair-step beaver ponds holding numerous brook trout. Some of these make it to the river below the Brush Creek confluence. Resident trout have abundant caddis, leeches (small, black, with imitations tied on 3X long streamer hooks, size 10-12), snails, a reduced number of mayflies (BWO, PMD, tricos) because of silt, and some yellow sallies.  Sadly, the silt also limits the number of large stoneflies in the river below the dam, but faster waters above the dam host the largest giant stonefly nymphs I’ve seen anywhere. Also present are crayfish, actually in the river above and below the reservoir. That presence provides evidence that this river is extremely rich in nutrients, particularly bicarbonates.   Without question the best time to fish this part of the river begins the first of October when irrigation water is no longer needed and extends into November or when winter makes roads tough to negotiate.  The low water concentrates trout into the deeper holes and runs. What flies should be in the fly box for fishing the river below the Dam, you ask?  Streamers in both colorful and somber shades are your best bet for encountering the largest trout.  Thick bank side grasses host volumes of hoppers which stay numerous until killing frosts hit.  Rocky banks host ants and beetles in abundance. Of the mayflies present tricos seem the most numerous, but they are in good concentrations only at specific locations. Look for their spinner falls to provide some good late morning and mid day fishing at these locations.  When October rolls around PMDs are rare, but BWOs are active. As in any water their hatching numbers are best during overcast conditions.  Traditional attractor patterns, wet and dry work well in riffles and runs. Visit us for more information on this river which is one of the last strongholds for Yellowstone cutthroat trout.