Using social cultural career theory (SCCT) linked with tenets of equity, we examined the role of participation in science and engineering fairs (SEFs) on youth's science, technology, engineering, and mathematics (STEM) educational and career choices. We analyzed data for evidence of the SCCT constructs of self-efficacy, interest, and learning experiences using constructs of Native American (NA), culturally responsive, and rural equitable pedagogies. Qualitative data included semi-structured interviews, focus groups, practice presentations of SEF prtojects, classroom observations, and mentoring students. Quantitative data consisted of two surveys: STEM Semantics Survey and the Motivation Strategies for Learning Questionnaire. Qualitative results reveal how the teacher built self-efficacy using equitable pedagogy by putting the students in control of their projects, created a network of experts in various science disciplines, developed a culture of mentorship that promoted belonging, and removed barriers for student participation by blending academics with culture for NA and rural mixed socioeconomic status students. She evoked asset-based pedagogies that inspired students to further their education and go into STEM fields. Quantitative findings reveal former student's orientation to participation in science fair activities related to their high interests, perceptions of a challenge, curiosity, and emerging mastery, where students demonstrated high [Correction added on February 17, 2021, after initial publication on February 04, 2021; the displayed quote in the section entitled "Dr. Olson successfully petitioned…" was initially placed as text due to a production error and has been reinstated.] dispositions in science and engineering and self-identified as STEM people. Implications include the use of SCCT, linked with equitable pedagogies to understand interest in STEM fields, mentoring, tapping into the expertise of local professionals to support development of projects, and navigating cultural barriers to provide access for underrepresented youth.