RESULTS 



The Blackfoot River changes in character several times 

 throughout its length. Available fish habitat in the river is a 

 function of the river's physical characteristics, which in turn, 

 is influenced by the adjacent geologic features. Based on 

 relatively distinct breaks in physical characteristics, the river 

 was divided into five reaches: Reach 1, Headwaters to Lincoln; 

 Reach 2, Lincoln to Nevada Creek; Reach 3, Nevada Creek to 

 Monture Creek; Reach 4, Monture Creek to Belmont Creek; and Reach 

 5, Belmont Creek to the mouth of the Blackfoot River. These 

 reach breaks also correspond with relatively distinct changes in 

 the composition of the Blackfoot River fishery. 



PHYSICAL CHARACTERISTICS OF THE BLACKFOOT RIVER 



Reach 1: Headwaters to Lincoln 



(RM 132.4 to 110) 



Stream gradient of the Blackfoot River appears to play a 

 significant role in the changes in fish habitat. Gradient of 

 the Blackfoot River generally is steep in the headwaters 

 averaging 24.56 ft/mi to Poorman Creek (Figure 2). In this 

 reach, beaver dams are common in the main channel and the stream 

 flows through large meadow areas. Pools are deep and riffles 

 normally appear gravelly (0.125 to 2.99 in. dia.) with some 

 rubble sized (3.00 to 11.9 in. dia.) particles. The Blackfoot 

 river goes underground upstream from Lincoln almost annually and 

 reappears again with major ground water inflows and spring type 

 creeks just below Lincoln. 



Reach 2 : Lincoln to Nevada Creek 



(RM 110 to 67.8) 



Gradient decreases below Poorman Creek (below Lincoln) to an 

 average of 10.2 ft/mi maintaining that grade to Arrastra Creek 

 about 20 miles downstream. Deposition of large quantities of 

 fine sediments in pools and riffles is a commonly observed 

 feature in this reach. The stream channel develops a strong 

 meandering pattern and log and debris jams are common. Stream 

 bank cover is predominately coniferous forest with lots of woody 

 brush cover. This reach is largely in a natural condition 

 because of frequent flooding and a well developed riparian zone. 

 The pools are frequently greater than 6 ft in depth. Fish cover 

 is predominately provided by the woody debris in the channel. 

 High water clarity, lack of water surface roughness, and fine 

 sediment (< 0.125 in. dia.) accumulation on the bottom make open 

 water observation of fish easy. From Arrastra creek to below 

 Nevada Creek gradient declines to 4.2 ft/mi. Fish habitat 

 remains similar to the Poorman to Arrastra section with possibly 



