Minnesota OER Commons"Minnesota OER Commons seeks to support educators, curriculum experts, and administrators across K-12 and higher education in creating affordable, high quality content solutions using Open Educational Resources (OER). Minnesota OER Commons is part of a statewide collaborative called Minnesota Learning Commons (MnLC), which offers consulting, training, and a suite of tools for the use of OER in all types of learning and classrooms."
Use the search bar on the homepage for find lesson plans (as well as a lot of other content for classroom use!).