Montana Department of Transportation

Public Involvement

MT 21 Bridges (Simms – Augusta)

MT-21 Bridges project logo

STPB-BH-BR 81022(2)
UPN 7938000

Project Overview

MT-21 Elk Creek – Hogan Bridges - 6-3-2019 UPDATE

MT - 21 between US 287 and the Hogan Slough bridge at milepost 0.7 has been re-opened. MDT was able to repair the erosion and open the highway late Friday, May 31st. Additional repairs will be occurring, including pavement on the gravel patch, but the highway is expected to remain open.

Elk Creek Bridge image
Elk Creek Bridge

Hogan Slough Bridge image
Hogan Slough

The project includes 11 locations on Montana-21 between MP 19.8, west of Simms, and 0.1, east of Augusta, in Cascade and Lewis & Clark Counties. These bridges and stockpasses were built in the 1930s and are too narrow to meet modern design standards.

Three wooden bridges can be replaced with culverts and the recovery zone can be flattened to eliminate the need for guardrail. Guardrail will be upgraded on one concrete bridge and three wooden bridges that will be re-decked. Right-of-way acquisition and utility relocation will be required. The public can anticipate seeing construction starting in 2020. In order for the Montana Department of Transportation to deliver these improvements, construction will result in detours and road closures. Drivers may experience some delays.

Due to recent flood events, the work type and schedules for the three bridges closest to Augusta (mileposts 0.1 Elk Creek, 0.2 Elk Creek Overflow and 0.8 Hogan Slough) are being re-evaluated.

Purpose and Need

  • The project has been nominated to address safety concerns based on bridge width and guardrail blunt ends. The scope is to rehabilitate, widen and overlay the decks and upgrade the guardrail or replace bridges with culverts.
  • These stock passes and bridges are nearing the end of their useful life.
  • The current bridges are only 21’ wide and the blunt end guardrail and lack of guardrail are safety problems.
  • The removal of bridges and blunt end bridge rail and replacing with culverts and a wider finished surfacing, as well as slope flattening will enhance safety along this route. Widening the bridge deck and placing new guardrail will provide an increased level of safety for the traveling public.
  • Rehabilitating the bridges to increase width or replacing with culverts is a cost-effective option that utilizes fewer resources than reconstruction. The existing wooden/paved decks will be replaced with corrugated steel decks and paved with plant mix.

How can I stay informed?

As the project progresses, this web page will be updated with public involvement notices as they become available. Notices will also be distributed to those on the project's mailing list.

MDT encourages members of the public to join the project's mailing list by submitting their contact information to Christie McOmber or by submitting a comment using the online comment form.

Information will be published on this website, in local media venues, and via newsletters throughout the project development process.