In recent decades much attention has been given to the optimization of professional development to support education reform; especially as it relates to science, engineering, technology and mathematics (STEM) fields. Many studies have shown that the most effective STEM professional development programs include active inquiry opportunities that take place over long durations. The Colorado School of Mines (CSM) has developed, and hosts, a professional program that works to address these needs. The "Water-Energy Education for the Next Generation" (WE[superscript 2]NG) is a National Science Foundation funded Research Experience for Teachers (RET). The WE[superscript 2]NG program is a six-week summer training that immerses K-12 educators in state-of-the-art research at CSM through the highly interdisciplinary lens of the water-energy nexus. The WE[superscript 2]NG model also includes industry field trips, content and pedagogy workshops and book club focusing on science communication. Program effectiveness is evaluated through surveys given to participants before, during and after the program. Pre- and post-program surveys indicate that WE[superscript 2]NG supports teacher confidence and growth in teachers of all grade levels and that participant satisfaction outcomes are likely related to the ratio of elementary, middle and high school teacher participants. Surveys given during the program reveal consistently positive feedback and that satisfaction with collaborative program elements is related to program duration. Overall, survey results illustrate that the WE[superscript 2]NG RET program is an effective professional development model for K-12 STEM educators.