Informal learning opportunities are increasingly being recognized as important for youth participation in authentic experiences at the intersection of science, technology, engineering, and math (STEM) (Dorsen, Carlson, and Goodyear 2006). These experiences may involve specialized equipment and dedicated time for learners to gain familiarity with the relevant scientific and engineering practices (i.e., designing experiments on their own, struggling to make sense of data, learning from their own mistakes and the results of peers), which often go beyond the classroom. However, the educators who guide the implementation of these informal efforts may need specific training, and they may need to be creative in designing learning experiences under their setting’s unique constraints. Best practices for professional development for classroom teachers include active inquiry opportunities and an emphasis on content and its relevance to the classroom, extended over a long period of time (Birman et al. 2000; Abell and Lee 2008; Darling-Hammond et al. 2009). However, the extant literature on teacher professional development tends to focus only on formal educators. This article draws on our experiences developing a program called Skynet Junior Scholars (SJS) to document how our professional development model engages both informal and formal educators with a range of skill sets. We describe how three SJS educators creatively forged new educational pathways between in-school and out-of-school STEM learning, and we provide lessons learned and recommendations for others.