National Science Foundation (NSF) funded Research Experiences for Teachers (RET) programs provide opportunities for professional development for teachers. The goal of the RET site at North Dakota State University (NDSU), established in May 2020 (NSF Awards #1953102 and #2224135), was to increase the knowledge of secondary (6th to 12th grade) educators in the use of civil engineering to mitigate natural disasters and their ability to prepare their students to become leaders in STEM disciplines. The primary goal of this study is to assess the effectiveness of the professional development provided in preparing participants to teach STEM topics in their classrooms. The study utilized a mixed method approach and an external evaluator to present data on the responses to two online surveys and a self-interview conducted with the secondary educators in the Summer 2021 NDSU RET cohort. Three themes emerged: (1) difficulty with math, (2) lack of connection/examples, and (3) issues with open-endedness and time to get a response. Nearly all the teachers noted that experiments and simulations with data were helpful strategies in engaging their students in STEM topics. They found value in connecting these topics with real-world problems in the student's lives. Teachers had increased knowledge about the research projects, real-world applications, and other ways to engage their students in STEM (specifically, civil engineering). Their knowledge was further increased by their interactions with other teachers in the RET program as well as through the presentations that the other teachers delivered during the summer activities.