Population health data are used to profile local conditions, call attention to areas of need, and evaluate health-related programs. Demand for data to inform health care decision making has spurred development of data sources and online systems, but these are often poorly integrated or limited in scope. Our objective was to identify existing data about diabetes mellitus-related conditions in Minnesota, build an online data resource, and identify what data are currently missing that, if available, would better inform assessment of health conditions in the state. A Web site was developed and populated with existing data and data not available elsewhere. It features functionality identified as most important by users, such as maps and county profiles. The site could serve as a flexible tool for stakeholder engagement, but issues were identified during development, including concerns about interpreting map data and open questions about sustainability, that need to be addressed.