The Washington State Department of Transportation (WSDOT) says it is moving into preliminary design and a federal environmental review process after permanently closing the State Route 165 Carbon River/Fairfax Bridge in April 2025, citing severe structural damage on the 104-year-old span.

While the bridge is in Pierce County, the closure matters to many Cowlitz County residents who use Mount Rainier as a core recreation outlet—especially the northwest side near Mowich Lake—via trips that often route through the I-5 corridor and SR 410/SR 162 connections. The shutdown also serves as a reminder for southwest Washington: decades of deferred infrastructure maintenance doesn’t just “show up” as inconvenience—it can become an abrupt loss of access, with few immediate alternatives.

WSDOT’s Jan. 8, 2026 update lays out what it says it learned from inspections, what the planning study recommends, and what comes next. (WSDOT blog: https://wsdotblog.blogspot.com/2026/01/next-steps-for-carbon-river-bridge.html)

Why WSDOT says it closed the bridge

WSDOT closed the single-lane truss bridge after inspections found a support column “bent and buckling,” along with “advanced deterioration” in multiple gusset plates—critical connectors within the bridge’s truss system. WSDOT permanently closed the bridge to all traffic on April 22, 2025.

WSDOT’s April 22, 2025 news release describes the column as bent “in two directions” and says the bridge was no longer safe for vehicle, pedestrian, or bicycle travel. (WSDOT: https://wsdot.wa.gov/about/news/2025/103-year-old-sr-165-carbon-river-fairfax-bridge-permanently-closed)

What WSDOT says the planning study found

After the closure, WSDOT launched a planning study (March–December 2025) to evaluate long-term access across the Carbon River Canyon. In its Jan. 2026 update, the agency says it gathered thousands of public comments through online and in-person open houses, with common themes including restoring access, rebuilding near the current bridge, and minimizing impacts on local communities and businesses.

The planning study webpage lists the study budget at $1.5 million and links to the final report. (WSDOT planning study page: https://wsdot.wa.gov/construction-planning/search-studies/sr-165-carbon-river-fairfax-bridge-planning-study)

Two alternatives are moving forward

WSDOT says two alternatives are being advanced into preliminary design and environmental review:

  • Replace the bridge just north of the existing location; or
  • Keep SR 165 closed and remove the Carbon River/Fairfax Bridge.

WSDOT says it allocated about $7 million in preservation funding in the 2025–27 transportation budget to start this next phase, which includes engineering work and environmental review. (WSDOT news release: https://wsdot.wa.gov/about/news/2026/next-steps-sr-165-carbon-river-fairfax-bridge)

Environmental review could take two years

WSDOT says it expects a roughly 24-month National Environmental Policy Act (NEPA) process, which would analyze impacts to land, water, wildlife habitat, and human health, and would involve review by other agencies including the Federal Highway Administration and U.S. Fish and Wildlife, among others.

WSDOT also notes that the bridge is listed in the National Register of Historic Places, meaning federal historic preservation requirements (including Section 106 review under the National Historic Preservation Act) would be part of the process before any bridge removal could occur.

A private, gated bypass remains limited

In the meantime, WSDOT says a nine-mile emergency bypass route exists for residents and first responders who live south of the closure, but it is a privately owned, gated logging road and is not open to the general public. WSDOT says it negotiated emergency access agreements with five private property owners and is working on upgrades such as automatic gates and a revised lock-and-key system.

WSDOT previously emphasized in 2025 that the emergency detour was not public and that there was no public access from SR 165 to Mount Rainier’s northwest corner because of the closure. (WSDOT April 2025 release: https://wsdot.wa.gov/about/news/2025/103-year-old-sr-165-carbon-river-fairfax-bridge-permanently-closed)

Why this matters in Cowlitz County

Even when a bridge closure happens outside our county line, it’s a warning signal for communities like Longview and Kelso that rely on state routes, freight corridors, and aging public infrastructure that can fail suddenly when maintenance is perpetually deferred.

WSDOT’s own messaging frames the Carbon River closure as part of a bigger structural problem: thousands of bridges statewide competing for limited preservation funding through a transportation budget set every two years. When public agencies are kept on austerity rations and expected to “do more with less,” the predictable outcome is that safety-driven closures become the only option left—after years of warnings and load restrictions.

What happens next

WSDOT says the next phase will include geotechnical work (soil and rock investigations), surveying, right-of-way steps, and environmental permitting, with seasonal constraints due to sensitive habitat. The agency says there will be additional public input opportunities during environmental review.

For readers tracking the issue: the key question is whether the state ultimately funds replacement—or chooses permanent closure and removal. Either path has costs. Replacement would restore access, but at a high price and multi-year timeline; closure would reshape travel, tourism, and rural connectivity for the region indefinitely.

Sources

Correction note: WSDOT’s blog post is dated Thursday, Jan. 8, 2026. The permanent closure date referenced by WSDOT is April 22, 2025 (after an initial closure on April 14, 2025).