Business Loop I-70 - Idaho Springs

Mostly decommissioned in 2016, the Idaho Springs business route from Interstate 70 lined Colorado Boulevard (old U.S. 6-40) through the linear city. Designated as Route 070K by the Colorado Department of Transportation, the 2.711 mile long route originated from I-70 at a half diamond interchange (Exit 239) with Stanley Road (CR 312) just outside the western city limits.

Passing just north of the city center, Business Loop I-70 intersected the north end of SH 103. SH 103 was subsequently truncated 0.082 miles south of Colorado Boulevard to Idaho Street.

The east end of Colorado Boulevard was rebuilt from a tight parclo interchange between April and Fall 2015. Work involved replacing the Colorado Boulevard Bridge over I-70 and realigning the boulevard slightly east. A roundabout was also added where the north side ramps come together, while separate ramps along I-70 east for Colorado Boulevard were consolidated. The new overpass accommodated the I-70 Mountain Express Lanes project.¹

Construction at the east end improved the south side I-70 Frontage Road to provide connectivity with the section rebuilt in 2012 linking to the Hidden Valley / Central City interchange at Exit 243. Future work paves the gravel section of CR 314 along the north side of Santa Fe Mountain.

Home to over 1,800, Idaho Springs is perhaps best known for its mineral baths, which give the city its name. One of the more interesting side trips from Idaho Springs is the "Oh My God" Road, which connects Idaho Springs with Central City and Blackhawk (SH 119 in Gilpin County) via Clear Creek County Route 279 and Gilpin County Route 279.

Signs along Interstate 70 were greened out in 2016 to remove Business Loop I-70. Additionally, shields for both the business route and SH 103 were not posted along Colorado Boulevard in Idaho Springs, and no signs were noted for the route between 20th Avenue and the roundabout at Exit 241 from the west. Route 070K was still inventoried by CDOT as of April 2017. Colorado Boulevard was eventually relinquished by CDOT with the exception of 0.212 miles at Exit 239 to the west (Route 070K) and a 0.523 mile long section (Route 070R) at Exit 241 to the east.

East

Business Loop I-70 eastbound overtakes Stanley Road east from Exit 239 to Colorado Boulevard to enter the Idaho Springs city limits. 08/11/16

The initial stretch through Idaho Springs consist of residential blocks north and south of Colorado Boulevard. This scene looks at 6th Avenue. 08/11/16

A trailblazer directs truck traffic headed to I-70 east to remain along Colorado Boulevard in lieu of forthcoming SH 103 south on 13th Avenue. 08/11/16

This sign assembly for SH 103 south on Business Loop I-70 east was removed by 2016 and replaced with a new signage at 12th Avenue by 2018. SH 103 commences a 22.41 mile long route to Echo Lake and Squaw Pass from Idaho Street, 0.082 miles south of Colorado Boulevard. 09/01/04

Miner Street east merges with Business Loop I-70 (Colorado Boulevard) by a shopping center. 08/11/16

Business Loop I-70 east expands into a commercial boulevard from Miner Street to I-70. 08/11/16

Traffic separates at a roundabout for the westbound on-ramp back toward Empire and the continuation of Colorado Boulevard across I-70. 08/11/16

Spanning Interstate 70 on a 2015-built overpass, Colorado Boulevard meets County Road 314, the south side frontage road, and the eastbound on-ramp for Denver. 08/11/16

Ramp meters operate during peak travel periods for inbound Interstate 70. 08/11/16

West

Construction of the new overpass for Colorado Boulevard above I-70 included the addition of a roundabout with the north side ramps from Interstate 70. 08/11/16

The westbound off-ramp (Exit 240) ties into the roundabout opposite the entrance ramp to Grand Junction. 08/11/16

A guide sign references just Colorado Boulevard, with the Business Loop unsigned from this point west through Idaho Springs. 08/11/16

A number of motels, restaurants and gas stations line Colorado Boulevard west to the split with Miner Street. 08/11/16

Miner Street parallels Colorado Boulevard one block to the south to the Idaho Springs city center. 08/11/16

Older traffic lights in operation along Colorado Boulevard at the Idaho Springs Fire Department, east of 20th Avenue. 08/11/16

Reassurance marker for Business Loop I-70 west at Colorado Boulevard and 17th Avenue. This assembly may have been removed during construction in 2016. 02/02/02

Confirming marker for Business Loop I-70 formerly posted west between 13th Avenue (former SH 103 south) and 12th Avenue. This assembly was removed by 2016. 09/01/04

Colorado Boulevard westbound at 7th Avenue. The actual springs that give Idaho Springs its name are located south of this point. 08/11/16

Stanley Road branches southwest from Colorado Boulevard ahead of the Business Loop I-70 transition onto Interstate 70 west. Stanley Road parallels the freeway west to Downieville as old U.S. 6-40. 08/11/16

Photo Credits:

02/02/02, 09/01/04, 08/11/16 by AARoads

Connect with:
Interstate 70
State Highway 103

Page Updated 01-20-2021.