The federal Clean Water Act directs states to develop water 

 pollution control plans {Total Maximum Daily Loads or TMDLs) that 

 set limits on pollution loading to water-quality limited waters. 

 Water-quality limited waters are lakes and stream segments that 

 do not meet water-quality standards, that is, do not fully 

 support their beneficial uses. The Clean Water Act and EPA 

 regulations require each state to (1) identify waters that are 

 water-quality limited, (2) prioritize and target waters for 

 TMDLs, and (3) develop TMDL plans to attain and maintain water- 

 quality standards for all water-quality limited waters. 



The purpose of this report is to provide information that 

 will help the State of Montana determine whether the upper 

 Boulder River is water-quality limited and in need of TMDLs. 



PROJECT AREA AND SAMPLING SITES 



The project area is in Park and Sweetgrass Counties in 

 southcentral Montana. The Boulder River heads in the Absaroka- 

 Beartooth Wilderness Area of the Gallatin National Forest at an 

 elevation of about 3000 meters in the Absaroka Mountain Range. 

 The Absaroka Range is considered a part of the Middle Rockies 

 Ecoregion (Omernik and Gallant 1987) . The Boulder River is 

 classified B-1 in the Montana Surface Water Quality Standards. 



From its headwaters the river flows north for about 3 

 miles, following a steep gradient through a deep forested canyon. 

 The sampling sites addressed in this report are located in this 

 upper reach of the river. The river's substrate through this 

 reach is dominated by cobble and boulders, with gravel and coarse 

 sand as the embedding materials (Levine 1996) . From where it 

 leaves the mountains, the river flows northeast another 3 miles 

 through grassy foothills to the town of Big Timber, where it 

 enters the Yellowstone River. 



