Teachers face many barriers to climate change education, including access to resources. The U.S. national parks are an informal education sector that offers a variety of climate change educational resources (CCER). However, there are gaps in understanding teachers' use of these resources. This explanatory sequential mixed-method study aimed to better understand K-12 science teachers' awareness, use, and perceptions regarding CCER from U.S. national parks. The participants in this study included 209 K-12 science teachers. The survey results indicate that K-12 science teachers do use CCER from US national parks. Participants most frequently used social CCER, followed by material resources. The majority of CCER framed climate change locally. Most participants reported low levels of awareness regarding the collective CCER offered by national parks. The qualitative sample (n=18) identified several reasons and barriers regarding their use of CCER. Common reasons for using CCER included local connections, learning opportunities, and quality. Common barriers to using CCER included logistics, cost, and curriculum alignment. Barriers were most often associated with field trips. Participants also shared their perceived affordances and constraints. Finally, this study determined that CCER from national parks can interact in a "Network of Resources." Participants most frequently discussed interactions between material resources and social resources. A "Network of Resources" model was used to show the interaction of CCER for an elementary, middle, and high school teacher. These cases demonstrate how science teachers can incorporate multiple CCER from national parks into their climate change instruction. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]