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, that 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 to determine whether certain 

 segments of 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 in 

 northcentral Montana. The Teton River is a tributary of the 

 Marias River in the Missouri River Drainage. 



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

 Marshall Wilderness and converge just east of the Rocky Mountain 

 Front about 20 miles west of Choteau, Montana. The Teton River 

 begins in the Northern Rockies Ecoregion, flows across the 

 Montana Valley and Foothill Prairies Ecoregion, and ends near 

 Fort Benton in the Northern Great Plains Ecoregion (Omernik and 

 Gallant 1987) . 



The Teton River is classified B-1 above Deep Creek near 

 Choteau, B-2 between Deep Creek and Interstate 15, and B-3 from 

 1-15 to the mouth. The Teton River is stressed by dewatering for 

 agricultural irrigation, salinization (mostly discharges from 

 Freezeout Lake and Priest Butte Lakes) , channel instability, 



