Three years ago, defining STEM clubs as “any gathering of students that meets regularly in an informal environment to work on inquiry-based STEM related activities,” Science Foundation Arizona piloted STEM clubs in eleven schools. What we learned from these efforts was that there was an interest in STEM clubs across the state and that STEM clubs opened up possibilities that other types of specialized clubs, such as full robotics clubs, did not. Unlike these specialized clubs, STEM clubs appealed to all grade levels, especially K-8, and they allowed teachers and students to adjust the level and focus of the club in order to meet student needs and interests. With this knowledge in hand, we set out to develop a STEM club model that could be replicated on a large scale. To begin this process, during the past two years, SFAz has facilitated two statewide STEM Club conferences, coordinated the creation of an online STEM Club Guide, provided seed funding for 187 STEM Clubs, and helped to network almost 200 STEM clubs across the state. These efforts have directly impacted approximately 2000 students, and the momentum surrounding these efforts is growing rapidly.