| San Marcos to Blue Island (Illinois) | 1,712.51 mi (2,756.02 km) |
| San Marcos to Blue Springs (Missouri) | 1,337.67 mi (2,152.77 km) |
| San Marcos to Bluffdale (Utah) | 583.73 mi (939.42 km) |
| San Marcos to Bluffton (Indiana) | 1,832.29 mi (2,948.79 km) |
| San Marcos to Bluffton (South Carolina) | 2,098.25 mi (3,376.81 km) |
| San Marcos to Blythe (California) | 151.19 mi (243.32 km) |
| San Marcos to Blytheville (Arkansas) | 1,559.00 mi (2,508.97 km) |
| San Marcos to Boca Raton (Florida) | 2,259.73 mi (3,636.69 km) |
| San Marcos to Boerne (Texas) | 1,109.89 mi (1,786.19 km) |
| San Marcos to Bogalusa (Louisiana) | 1,604.71 mi (2,582.53 km) |
| San Marcos to Boiling Springs (South Carolina) | 2,007.87 mi (3,231.35 km) |
| San Marcos to Boise (Idaho) | 724.89 mi (1,166.59 km) |
| San Marcos to Bolingbrook (Illinois) | 1,691.58 mi (2,722.33 km) |
| San Marcos to Bolivar (Missouri) | 1,369.66 mi (2,204.25 km) |
| San Marcos to Bon Air (Virginia) | 2,236.37 mi (3,599.09 km) |
