Interstate 115 Montana

Interstate 115 Montana
Butte, MT•1.19 miles

Overview

Interstate 115, similar to unsigned I-315 at Great Falls to the north, comprises a short freeway spur with a lone interchange. Totaling just 1.197 miles per the Montana Department of Transportation (MDT) 2022 Route Log, I-115 doubles as the westernmost section of the Butte Business Loop for I-15/90. The business routes extend 0.539 miles east along Iron Street to Montana Street north beyond Exit 1.

Mileage by State

Montana1.19 mi

Data Sources

December 31, 2021 Interstate Route Log and Finders List

History

Map of Butte, Montana
Located at 5,538 feet above sea level, Butte is home to around 35,000 residents. The city and Silver Bow County form a consolidated government. I-115 provides a gateway toward the city center from the west.

Interstate 115 was part of the proposed urban Interstate numerology for Montana submitted to the American Association of State Highway Officials (AASHO) on July 31, 1958. AASHO approved the proposal on November 10, 1958.

Construction contracts to build Interstate 115 ran concurrent with the those for the I-15/90 overlap through Butte. Contracts to build a 2.6 mile long section of roadway, including all of I-115, and five bridge structures ran simultaneously with completion by September 30, 1964. Contracts to construct the western 2.7 miles of I-15/90 were scheduled to December 31, 1963, and the 5.5 mile section to the east through October 15, 1964.1

The eight mile long stretch of I-15/90 was dedicated on September 24, 1964. Work on the four lane, concrete freeway started in 1960 and cost $8 million.2

East End Business Route I-15 Business Route I-90 ‐ Butte, MT

Interstate 115 Business Route I-90 East Business Route I-15 North at Iron Street

I-115 east at Excelsior Ave - Butte, MT

A concrete median more in line with an at-grade arterial separates the roadways of I-115 at Exit 1 for Excelsior Avenue. 07/05/16

I-115 east at Excelsior Ave - Butte, MT I-115 east at Iron St - Butte, MT I-115 east at Iron St - Butte, MT

Business Route I-15 South Business Route I-90 West at Interstate 115

Business Loop I-15/90 west at I-115 - Butte, MT

Iron Street expands into a four lane boulevard west from Montana Street. Westbound Business Loop I-15/90 transitions into I-115 beyond the end of on-street parking at Clark Street. The first shield for Interstate 115 follows. 07/07/16

Business Loop I-15/90 west at I-115 - Butte, MT Excelsior Av north at I-115 - 2003

West End Interstate 15 Interstate 90 ‐ Butte, MT

Interstate 15 North Interstate 90 East at Interstate 115 Business Route I-15 Business Route I-90

I-15/90 east at I-115 - Butte, MT

Traveling east from Rocker, I-15 north / I-90 east run along a ridge above parallel Silver Bow Creek to Left Exit 124 for Interstate 115 east. 07/05/16

I-15/90 east at I-115 - Butte, MT I-15/90 east at I-115 - Butte, MT I-15/90 east at I-115 - Butte, MT I-15/90 east at I-115 - Butte, MT I-115 east at I-15/90 - Butte, MT

Interstate 115 Business Route I-90 West Business Route I-15 South at Interstate 15 Interstate 90

I-115 west at I-15/90 - Butte, MT

I-15/90 trailblazers appearing beyond the Excelsior Avenue entrance ramp take the place of confirming markers for Business Loop I-15/I-90 along I-115. 07/05/16

I-115 west at I-15/90 - Butte, MT I-115 west at I-15/90 - Butte, MT I-115 west at I-15/90 - Butte, MT

West End – Past Views

Past Views Gallery (Tap to Expand / Collapse Section)

Interstate 15 North Interstate 90 East at Interstate 115

I-15/90 east at I-115 - 2006

Expansion of I-15 north / I-90 east from the Rocker interchange included the replacement of the initial sign bridge for I-115. The added eastbound lane ends a short distance ahead. Photo by Steve Hanudel (05/21/06).

I-15/90 east at I-115 - 2006 I-15/90 east at I-115 - 2003

References

  1. Montana Highway Department. (1963). The Center line: Montana Highway Commission. Helena, MT.
  2. Montana Highway Department. (September, 1964). The Center line: Montana Highway Commission. Helena, MT.
Updated June 30, 2022