| San Marcos to Johnstown (Pennsylvania) | 2,158.14 mi (3,473.19 km) |
| San Marcos to Joliet (Illinois) | 1,686.94 mi (2,714.86 km) |
| San Marcos to Jonesboro (Arkansas) | 1,515.78 mi (2,439.41 km) |
| San Marcos to Joplin (Missouri) | 1,306.82 mi (2,103.12 km) |
| San Marcos to Joppatowne (Maryland) | 2,294.91 mi (3,693.30 km) |
| San Marcos to Juana Díaz (Puerto Rico) | 3,290.51 mi (5,295.56 km) |
| San Marcos to Junction City (Kansas) | 1,202.50 mi (1,935.24 km) |
| San Marcos to Juneau (Alaska) | 1,918.98 mi (3,088.30 km) |
| San Marcos to Jupiter (Florida) | 2,246.26 mi (3,615.01 km) |
| San Marcos to Jupiter Farms (Florida) | 2,240.07 mi (3,605.05 km) |
| San Marcos to Jurupa Valley (California) | 62.22 mi (100.13 km) |
| San Marcos to Justice (Illinois) | 1,705.90 mi (2,745.38 km) |
| San Marcos to Kahului (Hawaii) | 2,545.18 mi (4,096.07 km) |
| San Marcos to Kailua (Hawaii) | 2,601.84 mi (4,187.26 km) |
| San Marcos to Kalamazoo (Michigan) | 1,825.84 mi (2,938.41 km) |
