Habitat Assessments for the Upper Blackfoot River 



Introduction 



In 2001, we began geomorphic and habitat assessments of the upper mainstem 

 Blackfoot River upstream of the Landers Fork at rm 121.6, continuing downstream to 

 Stemple Pass Bridge (rm 108.9) in 2001 (Pierce et al. 2001, 2002). In 2002 and 2003, we 

 continued these surveys in the downstream direction with the inventory of a 54.9-mile 

 section of the upper Blackfoot River between the Stemple Pass Bridge and the confluence 

 of the North Fork at rm 54.0 (Figure 42). Our objectives were to: 1) assess mainstem 

 morphologic and habitat features including river temperature and riffle sediment regimes; 

 2) augment TMDL and related studies; 3) identify areas of simplilled habitat with 

 restoration potential; 4) provide a repeatable baseline for future monitoring; and 5) help 

 assess habitat use by telemetered fish. The purpose is to help identify limiting factors and 

 direct restoration activities. 



Study Area 



We stratified the 

 upper river into three reaches 

 (upper, middle, lower). The 

 upper reach extends from 

 Lincoln to Arrastra Creek 

 (rm 108.9 - 88.8). The 

 section begins at the lower 

 portion of an intermittent 

 reach - an area where the 

 river begins to gain 

 significant inflows from 

 spring creeks and 



groundwater during base- 

 flow periods. This gaining 

 reach provides a 



concentrated spawning area 

 for mainstem brown trout (FWP files) and very limited bull trout reproduction (FWP 

 files). Several basin-fed tributaries, all supporting WSCT populations enter the upper 

 reach (Pierce et al. 2000), most of which have been identified at various levels of fisheries 

 impairment (Pierce et al. 2002). The upper reach supports significantly higher salmonid 

 densities than the lower reach below Nevada Creek (Pierce et al. 2000, Results Part II). 



The middle reach extends from Arrastra Creek (rm 88.8) to Nevada Creek (rm 

 67.7). At this junction, the river loses slope and becomes highly sinuous and prone to the 

 deposition of fine sediment. No tributaries enter this 21 -mile reach. Stream bank erosion 

 and active channel migrations increase in the downstream portion of this reach. 



The lower reach begins at Nevada Creek (rm 67.7). a large degraded tributary to 

 the middle Blackfoot River, and extends to the mouth of the North Fork (rm 54.0). At 

 this point, the river becomes confined by moraine against the Garnet Mountain where a 

 major increase in channel slope and substrate size also occurs. Several small degraded 



Figure 42. Three habitat inventory reaches of the upper Blaclcfoot 

 River. 



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