Young learners come to school holding myriad conceptions about how the world works, particularly in the areas of science, technology, engineering, and mathematics, or STEM.1-3 Further, young students' conceptions are commonly based on fragmented knowledge or naïve perspectives that contribute to the importance of early exposure to and practice with scrutinizing situations scientifically.1,3 An important part of helping children gain the skills necessary to approach situations scientifically involves preparing them to conduct scientific inquiry.3 The development of critical thinking skills and scientific approaches to problem solving should begin early in education.4 However, lack of elementary teacher comfort and familiarity with inquiry may be a significant barrier hindering early learner experience with and development of inquiry skills.5 Additionally, although engineering topics are particularly well suited for teaching inquiry, most teachers, like the general public, are not well versed in engineering. Therefore, teachers are excellent candidates for participation in professional development that enhances their knowledge and comfort with teaching inquiry-based STEM curriculum and engineering content in particular.