The California Open Educational Resources Council (CAOERC) was formed in 2014 to find solutions to reduce the cost of college textbooks without impacting quality. Comprised of faculty from California's three public higher education systems, the CAOERC conducted a field study of 16 faculty using OER materials to discover practical knowledge about the challenges of adopting OER textbooks. The quality of the OER textbooks received positive reviews. The faculty also reported being more engaged with their teaching. The faculty felt that availability of OER support materials was a challenge to implementing OER. The following article presents the results of the CAOERC's study.