Interstate 115
| I-115 highlighted in red | ||||
| Route information | ||||
| Auxiliary route of I-15 | ||||
| Maintained by MDT | ||||
| Length | 1.194 mi (1.922 km) | |||
| Existed | 1971–present | |||
| NHS | Entire route | |||
| Major junctions | ||||
| West end | I-15 / I-90 in Butte | |||
| East end | I-15 BL / I-90 BL in Butte | |||
| Location | ||||
| Country | United States | |||
| State | Montana | |||
| Counties | Silver Bow | |||
| Highway system | ||||
| 
 | ||||
Interstate 115 (I-115) is a 1.194-mile-long (1.922 km) auxiliary Interstate Highway which connects I-15/I-90 to Butte in the U.S. state of Montana. The highway is concurrent with I-15 Bus./I-90 Bus. for its entire length. The highway travels from an incomplete interchange with I-15/I-90 through generally rural areas in western Butte. It also has an interchange with Excelsior Avenue before terminating. The entire route was built to Interstate standards during the 1960s, and was further changed in 2005.