Figure shows density of patients with diabetes and their distribution around the 5 NCDRTN sites by zip code. Greenville clinic site has widest distribution of darkly shaded zip codes, suggesting patients travel from outlying rural areas to seek medical care at this facility. Greensboro, Asheville, and Fayetteville sites have more concentrated distributions of zip codes, suggesting patients travel from areas that are tightly clustered around the urban centers. Maps generated by Esri, HERE, DeLorme, MapmyIndia, USGS, NOAA, NPS, OpenStreetMap contributors, and the GIS user community.