| Boulder to Lowell (Indiana) | 937.13 mi (1,508.17 km) |
| Boulder to Lowell (Massachusetts) | 1,757.76 mi (2,828.85 km) |
| Boulder to Lower Burrell (Pennsylvania) | 1,341.51 mi (2,158.95 km) |
| Boulder to Lowes Island (Virginia) | 1,482.15 mi (2,385.29 km) |
| Boulder to Lubbock (Texas) | 483.44 mi (778.03 km) |
| Boulder to Lufkin (Texas) | 841.73 mi (1,354.64 km) |
| Boulder to Luling (Louisiana) | 1,093.26 mi (1,759.44 km) |
| Boulder to Lumberton (North Carolina) | 1,482.76 mi (2,386.27 km) |
| Boulder to Lumberton (Texas) | 917.75 mi (1,476.98 km) |
| Boulder to Lutz (Florida) | 1,534.88 mi (2,470.16 km) |
| Boulder to Lynbrook (New York) | 1,654.59 mi (2,662.81 km) |
| Boulder to Lynchburg (Virginia) | 1,411.60 mi (2,271.74 km) |
| Boulder to Lynden (Washington) | 1,044.48 mi (1,680.92 km) |
| Boulder to Lyndhurst (Ohio) | 1,243.61 mi (2,001.40 km) |
| Boulder to Lyndon (Kentucky) | 1,058.48 mi (1,703.46 km) |
