| Boulder to Jeffersonville (Indiana) | 1,051.37 mi (1,692.02 km) |
| Boulder to Jenison (Michigan) | 1,022.85 mi (1,646.11 km) |
| Boulder to Jenks (Oklahoma) | 576.23 mi (927.35 km) |
| Boulder to Jennings (Missouri) | 804.59 mi (1,294.86 km) |
| Boulder to Jensen Beach (Florida) | 1,679.15 mi (2,702.33 km) |
| Boulder to Jericho (New York) | 1,660.09 mi (2,671.65 km) |
| Boulder to Jerome (Idaho) | 514.75 mi (828.41 km) |
| Boulder to Jersey City (New Jersey) | 1,633.53 mi (2,628.92 km) |
| Boulder to Jessup (Maryland) | 1,510.98 mi (2,431.68 km) |
| Boulder to Johns Creek (Georgia) | 1,229.08 mi (1,978.01 km) |
| Boulder to Johnson City (New York) | 1,524.98 mi (2,454.22 km) |
| Boulder to Johnson City (Tennessee) | 1,264.27 mi (2,034.65 km) |
| Boulder to Johnston (Iowa) | 612.88 mi (986.34 km) |
| Boulder to Johnstown (Colorado) | 27.61 mi (44.44 km) |
| Boulder to Johnstown (Pennsylvania) | 1,385.18 mi (2,229.23 km) |
