Sampling Locations in Upper Mississippi River Basin

Figure 1a. Upper Mississippi River Basin major tributary watersheds and sampling locations for 2015-17 study. Yellow dots mark mainstem Mississippi River, major tributary, and Chippewa River basin sampling sites that were visited quarterly during 2015-17; black dots and red dots mark targeted sampling sites visited one time during 2015-17. Creator: Sydney Foks, USGS, 2017.