Trinity County Bridges

Project Description

This project is located in the lower reaches of the Klamath Mountains in California, midway between Redding in Shasta County and the Northern Redwood Coast. Trinity County entered into an agreement with the Federal Highway Administration, Central Federal Lands Highway Division (FHWA-CFLHD) to replace five county-owned bridges. These bridges were identified as structurally deficient or functionally obsolete, and have been approved by the California Department of Transportation (Caltrans) and the FHWA, California Division Office for replacement under the FHWA Highway Bridge Program. These bridges are:

  • Coffee Creek Bridge (5C-048), on Coffee Creek Road, County Route 104
  • Mumbo Creek Bridge (5C-061), on Ramshorn Road, County Route 133
  • North Fork East Fork Hayfork Creek (Hayfork Creek) Bridge (5C-157), on East Fork Hayfork Road, County Route 343
  • Little Creek Bridge (5C-187), on Jordan Road, County Route 332
  • Adams Creek Bridge (5C-196), on Coffee Creek Road, County Route 104

The old structures were single span, with lengths ranging from approximately 37 feet to 60 feet and widths ranging from approximately 13 feet to 17 feet. Records indicate that these structures were built from 1955 to 1979.

CFLHD utilized a Design-Build method to deliver all five bridges. The RNR Construction – Dokken Engineering team was selected in October 2016. The Design-Build team selected a composite precast/prefabricated design for four of the most remote structures, thereby reducing the need to bring raw materials on-site. The replacement bridges have been designed in accordance with current seismic and structural design standards for the State of California. Minor approach work improvements enhanced curvature and sight distance lines. All work was completed in November 2017.

Key Project Dates

Advertise: Spring 2016
Construction: Summer – Fall 2017

Project Photos

Former Bridge at Ramshorn Creek

Former Bridge at Ramshorn Creek.

Former Bridge at Adams Creek

Former Bridge at Adams Creek.

New Bridge at Ramshorn Creek

New Bridge at Ramshorn Creek.

New Bridge at Adams Creek

New Bridge at Adams Creek.

Map showing general vicinity of project
View a larger interactive map of the project area.

Project Details
Project # CA HBP TRI CR104(1)
Project Name Trinity County HBP Bridges et al
Location Trinity County
Status Completed

Contact Information

Project Manager: James Herlyck
Phone: 720-963-3698

Federal Highway Administration
Central Federal Lands Highway Division
12300 West Dakota Avenue
Lakewood, CO 80228