Interstate 315
Interstate 315 is a 0.82 mile unmarked spur that links Interstate 15 to Great Falls via Business Route 15. The interstate is marked as Business Route 15.
| Three-digit Interstates from Interstate 15 | |
| I-115 | Montana |
| I-215 | California – Nevada – Utah |
| I-315 | Montana |
| I-515 | Nevada |
| past/ future | I-115: California – I-415: Utah |
Categories: United States road stubs