This article reflects upon an investigative study of the powerful impact that mentoring partnerships have on pre-college students and young engineering professionals in Hartford, CT. It was found that these partnerships can provide very strong foundations for a diverse pre-college student engineering pipeline that includes significant numbers of women and under-represented minorities. The approach used is based on the principle of cross-age peer mentoring and combines industry-based mentoring with diversity-aware mentor recruitment strategies to 1) cultivate and train a corps of diverse mentors; 2) develop a suite of informal mentoring activities; and 3) apply and generate knowledge about the impact of effective mentoring strategies in overcoming barriers to women and under-represented minorities in engineering. The mentoring program was established at three Greater Hartford area public schools serving different population segments: suburban, multicultural suburban, and urban tuition-free charter school. Diverse engineering professionals were recruited from local tech companies and trained to hone their mentoring skills. Additionally, mentoring assistants, including female and minority undergraduate engineering students, were recruited to help during mentoring sessions. The mentoring activities, evidence of program success, and future plans are presented and discussed. Results show that students who participate in industry-based mentoring are 55% more likely to demonstrate more interest and confidence in STEM subjects as well as 25% more likely to show greater interest in pursuing STEM careers.