Project Summary/Abstract Firearm injuries are the leading cause of death among youth in the United States and rates of firearm-related suicides among rural youth are increasing at an alarming rate. Reducing access to firearms is a key component of suicide prevention because 91% of suicide attempts with a firearm are fatal. Although safe firearm storage reduces risk of firearm injury and death, few interventions exist that are tailored to rural communities where firearms are prevalent and an important part of community and family culture and where health care access disparities limit opportunities for safe storage education. Store Safely is a multi-component online primary prevention strategy designed via a university-community partnership specifically for rural firearm owning families that has shown promise in terms of its acceptability, feasibility, and preliminary impact. In a sample of 43 rural families, 98% reported engaging with all intervention components and 86% completed a home safety checklist. 40% of families self-reported making a change to their storage, such as purchasing gun locks, safes, or lockboxes; separating ammunition from weapons; reviewing the safety of current storage practices; and relocating firearms to a location harder to access by their children. 80% found Store Safely to be culturally sensitive and would recommend the materials to other parents. In response to this urgent need and RFA-CE-23-006 (Funding Option B) we will use a community-based participatory research (CBPR) approach and a hybrid two effectiveness-implementation framework to test this innovative, highly scalable online intervention. Our specific aims include: 1) refinement of the Store Safely intervention, incorporating feedback from the pilot trial and our community partners, 2) a pilot RCT of 20 families to refine measures and procedures, and 3) a hybrid-two trial with 800 rural firearm owning families randomized to receive Store Safely or a wait list control to provide definitive assessment of the impact of Store Safely on the primary intervention target of locked firearm storage as well as mechanisms of intervention to include knowledge, attitudes, and behavioral intentions as well as family safety behaviors, such as home safety checks. Implementation questions are designed to identify the most fruitful means of reaching and recruiting families to the intervention. Our team of investigators is uniquely poised to successfully lead this study given our lengthy track record of community-based participatory research, the development of interventions for youth at risk for suicide and firearm injury, and implementation science. If found to be effective, Store Safely has the potential to reduce suicide mortality in rural areas by capitalizing on the strengths of rural communities to enhance safety.