Project Area and Sampling Sites 



The project area is located within the Canadian Rockies and Northwestern Glaciated 

 Plains Ecoregions (USEPA 2000) in the Montana counties of Glacier, Pondera, and Teton. 

 Mountain vegetation is mainly mixed conifer forest, with alpine tundra on the highest peaks. On 

 the plains, vegetation is mainly mixed grassland with pockets of aspen and pine parkland along 

 the Rocky Mountain Front (USDA 1976, Woods et al. 1999). The main land uses are recreation, 

 wildlife production, livestock grazing, and irrigated agriculture. 



The study streams are in the Cut Bank Creek (HUC 10030202) and Two Medicine River 

 (HUC 10030201) USGS hydrologic units, which are tributary to the Marias River. The larger 

 streams in the project area head along the east side of the Continental Divide south of Glacier 

 National Park. Birch Creek forms the southern Boundary of the Blackfeet Indian Reservation 

 and Cut Bank Creek forms part of the eastern boundary of this reservation. Most streams in the 

 project area are classified B-1 in the Montana Surface Water Quality Standards. Streams located 

 in Glacier National Park and the Bob Marshall Wilderness (South Fork Birch Creek) are 

 classified A- 1. 



Periphyton samples were collected at 19 sites on 10 streams (Table 1; Maps 1-8). Six of 

 the sampling sites are in the Canadian Rockies Ecoregion and 13 sites are in the Northwestern 

 Glaciated Plains Ecoregion. Elevations at the sampling sites range from 5,300 feet (South Fork 

 Birch Creek) to 3,300 feet (Two Medicine River near mouth). 



Methods 



Periphyton samples were collected following standard operating procedures of the 

 MDEQ Planning, Prevention, and Assistance Division. Using appropriate tools, microalgae 

 were scraped, brushed, or sucked from natural substrates in proportion to the importance of those 

 substrates at each study site. Macroalgae were picked by hand in proportion to their abundance 

 at the site. All collections of microalgae and macroalgae were pooled into a common container 

 and preserved with Lugol's (IKJ) solution. 



