The Idaho Transportation Department (ITD) is constructing improvements on State Highway 75 (SH-75) between Elkhorn Road and River Street in Ketchum.

SH-75 Elkhorn Road to River Street

The Idaho Transportation Department (ITD) is constructing improvements on State Highway 75 (SH-75) between Elkhorn Road and River Street in Ketchum.


Expect intermittent traffic shifts on SH-75

Motorists can continue to expect intermittent traffic shifts on SH-75 as crews continue work to widen the roadway.

Overview

Crews are constructing improvements to SH-75 between Elkhorn Road and River Street in Ketchum. Continue reading to learn more.

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Photo of the Trail Creek Bridge with traffic.

Two-way traffic open on the Trail Creek Bridge

The Trail Creek Bridge has opened to one lane in each direction!

Crews will continue work on and around the bridge. Please continue to slow down, pay attention to signage and stay alert for crews in the area.

Motorists can expect:

  • Traffic shifts & lane closures will occur on SH-75 and local roads. One lane will remain open in each direction on SH-75 between Elkhorn Road and Serenade Lane.
  • Short-term closures may occur on SH-75 between Serenade Lane and River Street. Residential & business access will remain open.
Photo of SH-75 Elkhorn to River - Work zone traffic.
Map showing detour route described in text.

River Street access restricted through late spring

SH-75 motorists wanting to head southwest on River Street (toward 2nd Avenue) will detour to 1st Street and Washington Avenue.

What to expect:

  • This detour will remain in place through late spring.
  • Flaggers may intermittently direct traffic in this area.
  • Access to northeast River Street (toward Leadville) will remain open.

What to expect in 2026:

  • Work will occur during the daytime.
  • Traffic changes will occur on SH-75 and local roads.
  • One lane is expected to remain open in each direction on SH-75 between Elkhorn Road and the Trail Creek Bridge.
  • Speed limits will be reduced to 25 mph.
Image shows vehicles driving on SH-75
Image shows vehicles driving on SH-75 with candlestick traffic control devices separating the work zone from live traffic.

In 2026, crews will:

  • Construct the west half of the Trail Creek Bridge.
  • Complete improvements to the intersection of SH-75 and Elkhorn Road.
  • Complete improvements to SH-75 between Elkhorn Road and Weyyakin Drive.
  • Widen SH-75 between Weyyakin Drive and River Street.
  • Construct improvements to the intersection of SH-75 and Serenade Lane.

Work hours

Work hours have been extended to complete the Elkhorn Road to River Street project as safely and quickly as possible. This change was made with the approval of the cities of Ketchum and Sun Valley.

Work is expected to occur: 

  • Monday-Friday from 6 a.m.-10 p.m.
  • Saturdays from 7:30 a.m.-7 p.m.
  • Sundays from 8 a.m.-7 p.m.
Traffic on SH-75 next to the work zone.
Map highlights SH-75 from south of Elkhorn Road to River Street.

Improvements

ITD is constructing several improvements to SH-75 between Elkhorn Road and River Street. These improvements include:

  • Widening SH-75 to five lanes between Elkhorn Road and Serenade Lane.
  • Widening SH-75 to three lanes with bike lanes and sidewalks between Serenade Lane and River Street, including on the Trail Creek Bridge. 
  • Upgrading the traffic signal at the SH-75/Elkhorn Road intersection.
  • Installing a traffic signal at the SH-75/Serenade Lane intersection.
  • Improving some local roads, including Serenade Lane and Elkhorn Road.
  • View detailed improvement plans.

Process & Schedule

  • Spring 2025 – Summer 2025

    Crews constructed:

    • The northbound lanes of SH-75 from south of Elkhorn Road to Serenade Lane.
    • Utility relocations and retaining walls between Serenade Lane and River Street.
  • Summer 2025 – Late 2025

    Crews constructed:

    • The southbound lanes of SH-75 from south of Elkhorn Road to Serenade Lane.
    • The northbound side of the Trail Creek Bridge.
    • Utility relocations and retaining walls between Serenade Lane and River Street.
  • 2026 – 2027

    Crews will construct:

    • SH-75 between Neil’s Way and River Street.
    • The southbound side of the Trail Creek Bridge.
    • Improvements to the intersection of SH-75 and Elkhorn Road.
    • Improvements to the intersection of SH-75 and Serenade Lane.

    Crews will also complete improvements to SH-75 between Elkhorn Road and Neil’s Way.

Impacts to Local Roads

Stay informed

To stay informed about the SH-75 Elkhorn Road to River Street project and sign up for updates: 

Frequently Asked Questions

Project Area Photos

Crews working on the Trail Creek Bridge in Ketchum.
Crews work on the Trail Creek Bridge – May 2026
Crews working on the Trail Creek Bridge in Ketchum.
Crews work on the Trail Creek Bridge – May 2026
Crews working on the Trail Creek Bridge in Ketchum.
Crews work on the Trail Creek Bridge – April 2026
Crews working on a support wall for the SH-75 project in Ketchum.
Crews work on a support wall along SH-75 – April 2026
The intersection of SH-75 and Elkhorn Road  with live traffic.
The intersection of SH-75 and Elkhorn Road – April 2026
Road work on SH-75 near the River Street intersection.
Work on SH-75 near River Street – April 2026

Downloads & Resources