Microplastics (MPs) are becoming one of the most cited emergent contaminants in the last decade. These tiny synthetic polymers are associated with human activity. The inadequate disposal of plastics has made this material a ubiquitous pollutant on beaches, rivers, lakes, and oceans. MP particles are a new type of pollution reported in the Great Lakes with unknown impacts in the ecosystem and human health. Little information is currently available on the composition, distribution, or fate of MPs debris in the western end of Lake Superior and St. Louis River Estuary. This research aims to identify possible sources, abundance, and MPs' potential to adsorb toxic compounds. We collected 22 samples from nine main tributaries rivers to western Lake Superior and 12 Creeks, and one inland lake in Wisconsin during summer and fall of 2017 and 27 during summer 2016. To determine the type of synthetic polymer, we used an FTIR-ATR Micro Spectrophotometer. The MPs were classified by color, size, and morphology. Results showed that fibers and fragments were the main MPs. St Louis and French Rivers presented a high concentration of cotton fibers. The PAHs fingerprinting was related to pyrogenic sources.