Fork of the Blackfoot
The North Fork of
the Blackfoot River, is a 4th order stream and is the largest tributary to the Blackfoot
River. The North Fork drains the western slopes of the Continental Divide in the
Scapegoat Wilderness Area flowing 34 miles before entering the Blackfoot River at river
mile 54. Discharge was 300 cfs near the mouth on August 16, 1989. The cold water
temperatures of the North Fork significantly improve the health of the aquatic community
in the Blackfoot River below the North Fork confluence. Although the North Fork below
the falls has sections of slightly meandering alluvial bottom, it is generally confined to
a narrow valley with a bed morphology dominated by highly variable boulder materials,
bedrock, rapids and irregularly spaced plunge pools.
The North Fork Blackfoot River is one
of the most important spawning tributaries used by fluvial bull trout in the Blackfoot
River Basin. In order to prioritize restoration resources, we developed a fisheries-based
restoration priority scorecard, based on biological, social and financial considerations,
for 83 impaired tributaries of the Blackfoot River. The North Fork is ranked 1 of 83
Restoration efforts in this tributary
have primarily been done in cooperation with irrigators to eliminate fish losses to
irrigation canals. Fish screening devices have been installed on all five canals
located between river mile 8.0 and 15.3.
The three different types of screens
used on the North Fork include:
(1) Drum Screen
(2) McKay Self-cleaning
paddle wheel design that we have on three of the ditches.
(3) Infiltration Gallery
|Before restoration on the North Fork.
||During installation of the infiltration gallery.
|After completion of the infiltration gallery.
||Headgate for the infiltration gallery.
Three levels of fish
sampling have been undertaken on the North Fork:
1) bull trout spawning surveys (redd
2) pre-and post-project relative
abundance of juvenile bull trout along the channel shoreline
3) mark-recapture populations estimates
in the lower reach of the North Fork (from river miles 2.1 to 5.9)
Livestock management has
also been improved along eight miles of the North Fork's riparian corridor.
Conservation easements are currently in place along 9 miles of the North Fork.