| Upper Grand Lagoon to Oskaloosa (Iowa) | 859.74 mi (1,383.61 km) |
| Upper Grand Lagoon to Oswego (Illinois) | 808.61 mi (1,301.33 km) |
| Upper Grand Lagoon to Oswego (New York) | 1,048.89 mi (1,688.02 km) |
| Upper Grand Lagoon to Otsego (Minnesota) | 1,127.12 mi (1,813.93 km) |
| Upper Grand Lagoon to Ottawa (Illinois) | 791.88 mi (1,274.40 km) |
| Upper Grand Lagoon to Ottawa (Kansas) | 795.40 mi (1,280.07 km) |
| Upper Grand Lagoon to Ottumwa (Iowa) | 837.67 mi (1,348.10 km) |
| Upper Grand Lagoon to Overland (Missouri) | 645.29 mi (1,038.49 km) |
| Upper Grand Lagoon to Overland Park (Kansas) | 787.90 mi (1,268.00 km) |
| Upper Grand Lagoon to Overlea (Maryland) | 822.23 mi (1,323.25 km) |
| Upper Grand Lagoon to Oviedo (Florida) | 293.24 mi (471.93 km) |
| Upper Grand Lagoon to Owasso (Oklahoma) | 719.61 mi (1,158.09 km) |
| Upper Grand Lagoon to Owatonna (Minnesota) | 1,045.56 mi (1,682.66 km) |
| Upper Grand Lagoon to Owensboro (Kentucky) | 530.19 mi (853.27 km) |
| Upper Grand Lagoon to Owings Mills (Maryland) | 814.94 mi (1,311.53 km) |
