This is an update to a previously archived data set, which is available at https://doi.org/10.13020/4zwr-t415. Here, additional sites for 2021, and additional data for 2022 and 2023 are given. There will be no further updates. 570 station occupations occurred along Lake Superior’s southwest shoreline where data were collected from Lake Superior and its watershed in the region generally between Duluth-Superior and Ashland, WI. Parameters include forms of carbon, nitrogen, and phosphorus, along with total suspended solids, chlorophyll, and phycocyanin.