St. Louis River Area of Concern surface water nutrient (TP, TN, NOx-N, NH4-N), dissolved oxygen, and particulate (TSS, chlorophyll a) concentration data from 2012 and 2013 reported in Bellinger et al. 2016, Journal of Great Lakes Research 42:28-38. This dataset is associated with the following publication: Bellinger, B., J. Hoffman , T. Angradi , D. Bolgrien , M. Starry, C. Elonen , T. Jicha , L. Lehto, L. Seifert-Monson, M. Pearson , L. Anderson, and B. Hill. Water quality in the St. Louis River Area of Concern (AOC), Lake Superior: An historical perspective with assessment implications. JOURNAL OF GREAT LAKES RESEARCH. International Association for Great Lakes Research, Ann Arbor, MI, USA, 42(1): 28-38, (2016).