The commercial importance of lake whitefish (Coregonus clupea-formis) in Lake Michigan has resulted in increased demand for ef-fective allocation of harvest. Six genetic stocks of lake whitefish have been identified in Lake Michigan providing a framework for stock based management on the commercial fishery. However, bet-ter understanding of proportional stock harvest is required to prop-erly implement such a regime. The objective of this research is to use multi locus microsatellite data and mixed stock analysis (MSA) to identify the proportional stock harvest of lake whitefish sampled from the 2009 and 2010 Lake Michigan commercial harvest. Ge-netic samples (n equals150/sample) will be collected during spring, summer and fall (pre spawn) in 2009 and 2010 from two primary locations, Big Bay de Noc (MI) and North Moonlight Bay (WI), and from six randomly chosen (season and location) landing sites throughout Lake Michigan (total samples equals18). Samples will be genotyped at 11 microsatellite loci consistent with a reference dataset of 12 known spawning aggregates used to delineate the six primary genetic stocks. Mixed stock analysis of the commercial harvest will be performed using a conditional maximum likelihood estimate of genetic mixture implemented in ONCOR. Previous work has shown the efficacy of MSA for this reference database. Findings from research will aid in more efficient management of Lake Michigan’s commercial harvest of lake whitefish.