The Citizens for Positive Adolescent Choices, a substance use prevention coalition in and around Mason County, Illinois, works toreduce youth substance use and support healthy choices. - The Citizens for Positive Adolescent Choices (CPAC), a community coalition serving Mason County and the Midwest Central School District in Illinois, is seeking funding to expand targeted, data-driven prevention strategies to reduce youth alcohol, marijuana, and tobacco/nicotine use. Local Illinois Youth Survey data highlight urgent contributing factors, including low perceived risk of harm, favorable social norms, high perceived availability and access, and limited parent-child communication, conditions that this project is specifically designed to change. This project aims to achieve measurable reductions in past 30-day youth substance use by directly shifting the underlying drivers of behavior. To achieve this, the coalition will implement evidence-based strategies aligned with the Strategic Prevention Framework and seven strategies for community-level change. These efforts will include youth-focused prevention communication campaigns, school-based prevention education, peer-led social norms activities, parent engagement and communication campaigns, and environmental strategies to reduce youth access to substances. Key activities include county-wide prevention communication campaigns addressing tobacco/nicotine and marijuana use, evidence-based education for middle school students in a school setting, and youth leadership councils to develop peer-led messaging. Parent-focused campaigns and workshops will strengthen communication and reinforce clear expectations, while environmental strategies, such as Sticker Shock/Your Actions Matter campaigns and compliance checks, will reduce youth access to substances. These strategies will increase youth perception of harm, strengthen peer and parental disapproval, reduce perceived availability of substances, and improve parent-child communication. In addition, the coalition will strengthen its capacity by enhancing member engagement, expanding sector representation, and providing training and skill-building opportunities. These efforts will ensure a strong foundation to sustain long-term community engagement and impact. By aligning data-driven strategies with strong community partnerships, CPAC is positioned to produce measurable, population-level reductions in youth substance use and create lasting change in Mason County.