To address the issue of underrepresentation of historically excluded groups (HEG) working in STEM occupations, we developed GEODUC - "Geoscience Education, Oceanographic Discovery, Undergraduate Collaboration", a place-based summer bridge followed by a year-round mentoring program designed to increase student interest and retention in the geosciences. The goal of the program is to introduce core science, technology, engineering and math (STEM) majors and STEM-adjacent majors to real-world, practical applications and careers in the geosciences. Our program is divided into three core phases: (1) recruitment, (2) bridge program, and (3) a mentoring seminar series. Recruitment into the program is focused on community college students who are transferring into the University of Washington (UW) as community colleges are an important route to STEM careers for students of high potential from marginalized communities. The bridge program is a 10-day immersive experience Friday Harbor Laboratories, UW's marine station on San Juan Island, WA, before fall quarter begins. This residency program facilitates organic collaboration and community among the participants while also building foundations in critical thinking and skills in scientific inquiry. During their first academic year at UW, the participants enroll in a one-hour weekly mentoring seminar. Seminar themes vary by quarter, and include: academic success (fall), getting involved in research (winter) and career opportunities (spring). Programming is assessed using frequent surveys: pre- and post-residency program, daily during the bridge program, weekly during the quarter seminar courses. Assessments are aimed at exploring program impact on science knowledge and skills, geoscience research and career network, sense of belonging within, and outside of, major. After their first quarter at UW, participant experience and attitudes are assessed through interviews. Preliminary results and lessons learned from the first two cohorts will be presented.