Though science teachers use curricular materials from a range of sources, the nature of the science education materials that exist in the public domain or that are licensed for free use has not been the focus of much prior research. In this study, Open Educational Resources (OER) that can be accessed through the OER Commons platform were examined in terms of their characteristics and use using public Internet data mining methods. The author evaluated 8,937 life science, physical science, and applied science resources in terms of their material type, grade level, license type, number of endorsements by approved organizations (e.g., a state department of education), alignment with the Next Generation Science Standards (NGSS), and number of views. Many resources were readings and laboratory investigations, and most were for postsecondary science classes, though many were intended for high school, middle school, and elementary classrooms. Relatively few resources were endorsed, and fewer still were explicitly aligned with the NGSS, suggesting the need for greater alignment of standards across states. To provide a richer set of accessible curricular resources for educators, several implications for practice and policy are considered.