| Boulder to Kenosha (Wisconsin) | 917.29 mi (1,476.24 km) |
| Boulder to Kent (Ohio) | 1,252.07 mi (2,015.01 km) |
| Boulder to Kent (Washington) | 985.02 mi (1,585.24 km) |
| Boulder to Kentwood (Michigan) | 1,034.56 mi (1,664.96 km) |
| Boulder to Kerman (California) | 832.85 mi (1,340.34 km) |
| Boulder to Kernersville (North Carolina) | 1,390.70 mi (2,238.12 km) |
| Boulder to Kerrville (Texas) | 771.41 mi (1,241.46 km) |
| Boulder to Kettering (Maryland) | 1,514.02 mi (2,436.57 km) |
| Boulder to Kettering (Ohio) | 1,116.84 mi (1,797.39 km) |
| Boulder to Kewanee (Illinois) | 806.93 mi (1,298.63 km) |
| Boulder to Key Biscayne (Florida) | 1,750.94 mi (2,817.87 km) |
| Boulder to Key Largo (Florida) | 1,765.24 mi (2,840.88 km) |
| Boulder to Key West (Florida) | 1,728.61 mi (2,781.93 km) |
| Boulder to Keystone (Florida) | 1,527.92 mi (2,458.95 km) |
| Boulder to Kihei (Hawaii) | 3,275.74 mi (5,271.79 km) |
