Creating the Caltech Prevention Ecosystem: A Campus-Wide Approach to Improve Student Mental Health, Prevent Substance Use, and Reduce Suicide Risk - The California Institute of Technology (Caltech) will implement the Caltech Prevention Ecosystem, a campus-wide framework serving approximately 2,400 undergraduate and graduate students in Pasadena, California, to strengthen mental health promotion, suicide and substance use prevention, early identification, referral, and institutional capacity. A full-time Mental Health Prevention Specialist within Student Wellness Services will lead the initiative through four integrated pillars: Prevent, Identify, Respond, and Improve. Strategies include evidence-informed prevention and mental health promotion, gatekeeper training, peer and family engagement, campus-wide awareness campaigns, early identification and referral, an integrated crisis, referral, and lethal-means safety network, and program evaluation with campus and community partners. By Year 1, at least 75% of resident assistants, coaches, and student-facing staff will complete evidence-based gatekeeper training, increasing to 90% by Year 2. Campus-wide outreach will reach at least 2,500 students, faculty, staff, and families annually. The project will also report quarterly on training completion, awareness-message exposure, screenings, referrals, and service utilization and use these data to support continuous quality improvement and sustainable prevention infrastructure.