The South of the River Subarea Plan for the City of Star, Idaho, supports desired development patterns with a riverfront mixed-use activity center, surrounded by varied residential densities and connected by thoughtfully designed roads, trails, and paths. The detailed process included a subarea plan and a conceptual plan for a mixed-use activity center, traffic modeling, and floodplain analysis to ensure feasible development aligned with the subarea’s intent. Stakeholder and public engagement were crucial throughout the process. The final plan presented illustrative sketches, visual simulations, a strategic implementation guide, a code overlay, and text modification recommendations to realize the subarea vision. It provided more detail than the Comprehensive Plan, particularly for development at Star Road and along the Boise River, planning this area as the new downtown for Star.