| Keystone to Oswego (Illinois) | 990.56 mi (1,594.16 km) |
| Keystone to Oswego (New York) | 1,111.54 mi (1,788.86 km) |
| Keystone to Otsego (Minnesota) | 1,329.09 mi (2,138.96 km) |
| Keystone to Ottawa (Illinois) | 978.99 mi (1,575.53 km) |
| Keystone to Ottawa (Kansas) | 1,026.20 mi (1,651.51 km) |
| Keystone to Ottumwa (Iowa) | 1,049.55 mi (1,689.09 km) |
| Keystone to Overland (Missouri) | 855.72 mi (1,377.14 km) |
| Keystone to Overland Park (Kansas) | 1,016.52 mi (1,635.93 km) |
| Keystone to Overlea (Maryland) | 850.60 mi (1,368.91 km) |
| Keystone to Oviedo (Florida) | 93.26 mi (150.09 km) |
| Keystone to Owasso (Oklahoma) | 955.47 mi (1,537.69 km) |
| Keystone to Owatonna (Minnesota) | 1,249.75 mi (2,011.28 km) |
| Keystone to Owensboro (Kentucky) | 714.57 mi (1,149.98 km) |
| Keystone to Owings Mills (Maryland) | 847.28 mi (1,363.56 km) |
| Keystone to Owosso (Michigan) | 1,030.78 mi (1,658.88 km) |
