various levels of biological integrity and use impairment in 

 Montana streams (Bahls 1993, Bukantis 1998). 



The Clean Water Act further directs states to develop 

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

 set limits on pollution loading to water quality-limited 

 waterbodies . Water quality-limited waters are lakes and stream 

 segments that do not meet state 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 

 (MDEQ 1998) . 



The underlying purpose of this report is to provide 

 information that will help the state determine whether McDonald 

 Creek and the Teton River are water quality-limited and in need 

 of TMDLs . 



PROJECT AREA AND SAMPLING SITES 



The project area is in Teton and Chouteau Counties west and 

 east of the town of Choteau in northcentral Montana. McDonald 

 Creek is a tributary of the Teton River and the Teton River is a 

 tributary of the Marias River in the Missouri River drainage. 

 Periphyton samples were collected at two stations on McDonald 

 Creek and nine stations on the Teton River (Table 1) . 



The North and South Forks of the Teton River head in the Bob 

 Marshall Wilderness Area and converge just east of the Rocky 

 Mountain Front about 2 miles west of Choteau, Montana. The 

 source of McDonald Creek is McDonald Swamp, a unit of the Nature 

 Conservancy's Pine Butte Swamp Preserve. Pine Butte Swamp and 



