Despite great efforts and expenditures to promote science literacy and STEM career choices, the U.S. continues to lag behind other countries in science education, diminishing our capacity for STEM leadership and our ability to make informed decisions in the face of multiple looming global issues. I suggest that positive science identity construction (the integration of science into one's sense of self so that it becomes a source of inspiration and contributes to lifelong learning) is critical for promoting durable science literacy and pro-science choices. Therefore, the focus of this study was extraordinary professional development experiences for science educators that may significantly impact their sense of self. My hypothesis was that such experiences could positively impact educators' science and "science educator" identities, and potentially enhance their capacities to impact student science identities. The first part of this hypothesis is examined in this study. Further, I suggest that first-person narratives play an important role in science identity construction. Presenting a new conceptual model that connects experiential learning theory to identity theory through the narrative study of lives, I explored the impacts of subjectively regarded extraordinary professional development experiences on the science identity and science educator identity construction processes for a cohort of fifteen K-12 science teachers during a science-learning-journey to explore the volcanoes of Hawaii. I used a case study research approach under the broader umbrella of a hermeneutic phenomenology to consider four individual cases as lived experiences and to consider the journey as a phenomenon unto itself. Findings suggest science and science educator identities are impacted by such an experience but with marked variability in magnitude and nature. Evidence also suggests important impacts on their other identities. In most instances, science-related impacts were secondary to and/or embedded within the more holistic physical, intellectual, and emotional impacts. Rather than only targeting specific learning goals, as traditional professional development programs often do, this immersive experiential learning program integrated a wide range of human experience that were important factors, most notably, risk, social connections, permission and agency, and emotions in connection with more targeted science learning. Implications for future research and practice are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]