| Castelli Calepio to Odessa (Texas) | 5,611.21 mi (9,030.37 km) |
| Castelli Calepio to Ogden (Utah) | 5,447.57 mi (8,767.01 km) |
| Castelli Calepio to Oildale (California) | 5,995.07 mi (9,648.14 km) |
| Castelli Calepio to Ojus (Florida) | 4,961.35 mi (7,984.52 km) |
| Castelli Calepio to Okemos (Michigan) | 4,387.39 mi (7,060.81 km) |
| Castelli Calepio to Oklahoma City (Oklahoma) | 5,241.10 mi (8,434.73 km) |
| Castelli Calepio to Okmulgee (Oklahoma) | 5,175.18 mi (8,328.64 km) |
| Castelli Calepio to Olathe (Kansas) | 4,968.76 mi (7,996.45 km) |
| Castelli Calepio to Old Jamestown (Missouri) | 4,794.31 mi (7,715.69 km) |
| Castelli Calepio to Oldsmar (Florida) | 4,976.85 mi (8,009.47 km) |
| Castelli Calepio to Olean (New York) | 4,172.01 mi (6,714.20 km) |
| Castelli Calepio to Olive Branch (Mississippi) | 4,959.70 mi (7,981.87 km) |
| Castelli Calepio to Olivehurst (California) | 5,856.49 mi (9,425.11 km) |
| Castelli Calepio to Olney (Maryland) | 4,236.62 mi (6,818.18 km) |
| Castelli Calepio to Olympia (Washington) | 5,423.51 mi (8,728.29 km) |
