The purpose of this report is to provide information that 

 will help the State of Montana to determine whether the Redwater 

 River, the East Redwater River, and Little Dry Creek are water- 

 quality limited and in need of TMDLs . 



PROJECT AREA AND SAMPLING SITES 



The project area is in McCone, Dawson, and Garfield counties 

 in eastern Montana. The Redwater River begins in southern McCone 

 County and flows northeast for about 80 miles, joining the 

 Missouri River south of Poplar, Montana. The East Redwater 

 River, a major tributary, enters the Redwater River about 15 

 miles upstream from its mouth. Little Dry Creek was included in 

 this study as a least- impaired reference stream against which to 

 compare sites on the Redwater River. Little Dry Creek is a 

 tributary of Big Dry Creek and flows north through Garfield 

 County into Fort Peck Reservoir. Little Dry Creek is the next 

 major drainage to the west of the Redwater River. 



The project area is located in the Northwestern Glaciated 

 Plains Ecoregion (Omernik and Gallant 1987) . The watersheds of 

 all three streams overlie the Fort Union Formation, a coal- 

 bearing sedimentary deposit of Paleocene age (Taylor and Ashley, 

 undated) . Vegetation is primarily grassland and the main land 

 use is cattle grazing with some dryland farming. The town of 

 Circle (pop. 716) is located near the headwaters of the Redwater 

 River and is the only community along the three streams. 



Periphyton samples were collected in late May 1999 at 8 

 sites on the Redwater River, and 1 site each on the East Redwater 

 River and Little Dry Creek (Table 1) . Elevations of the sampling 

 sites range from about 3,000 feet near the head of the Redwater 

 River to 2,000 feet near the mouth. All three study streams are 

 classified C-3 in the Montana Surface Water Quality Standards. 



