The California Invasive Plant Council (Cal-IPC) worked with dozens of partner organizations to map invasive plants statewide and to build an online decision-support tool, CalWeedMapper, to use the data. Cal-IPC has used the tool to design landscape-level projects with regional partners, and has been successful in securing funds for on-the-ground implementation of high-priority projects. CalWeedMapper provides spatial information that serves as the foundation for selecting priorities and demonstrating clear rationale to funders. For many plants, the tool shows suitable range, both current and projected for mid-century, which allows climate change to be incorporated into prioritization. By viewing distributions at the landscape-level, early eradication projects can be supported by turning away from metrics like “acres treated” and toward the more important “acres protected.” CalWeedMapper serves as proof of concept for a national mapping system that would facilitate design of landscape-scale projects across state lines.