Data show that many high school students, especially those from underserved or underrepresented backgrounds, are unsuccessful in achieving a four-year college degree, particularly in Science, Technology, Engineering, and Math (STEM) careers. These young scholars often have strong potential and ambitious dreams, but face significant structural barriers in achieving their goals, resulting in substantial opportunity and knowledge gaps. We have developed a novel approach to help these students prepare for college admissions and achieve college success through intensive mentoring by STEM professionals and support through technology innovations. We developed a comprehensive, competency-based curriculum that includes academics, application preparation, essay development, financial aid, test preparation and college visits. Students complete a capstone portfolio project at the end of the summer intervention, and we continue to provide longitudinal support throughout their high school and college years. Over the past nine summers we implemented our model with an all-volunteer staff to achieve significant, measurable results: 168 students have participated in the program; 98% of surveyed program alumni are on-track to earning their four-year college degrees; and the majority plan to earn degrees in STEM and to pursue a graduate degree. Our outcomes significantly outperform both students from similar backgrounds and the overall student population. In this manuscript, we provide an overview of our model, insights into how this approach may be extended to other communities and suggestions for evaluating program efficacy in a data-driven framework.