Technical Abstract: Invasive plants continue to spread and impact rangelands in the western United States. Fortunately, many rangeland ecosystems still remain invasive weed-free.Cooperative prevention systems can safeguard these remaining areas. Local-level weed prevention areas (WPAs) prioritize prevention in the largely weed-free rangelands of eastern Montana. WPAs direct proactive approaches to weeds,a strategy more successful than common reactive approaches that focus on land already dominated by weeds. In a WPA, ranchers collectively implement specific strategies to protect rangelands from invasion over time. Social marketing campaigns are essential to guide long-view investments in prevention to county weed departments in eastern Montana.