National Trails Highway – Route 66

Route 66, also known as “the Mother Road”, “Will Rogers Highway” or “the Main Street of America”, was constructed in 1926 from Chicago, Illinois to Santa Monica, California. However, the road’s origins travel even further back in time before it was paved as one of the country’s first transcontinental highways “National Old Trails Road”. The road has served this country well as families left the Dust Bowl and headed west to California during the Great Depression; moving troops and supplies during World War II; and becoming a destination in itself to travelers seeking freedom of the open highway.

Route 66 signage painted onto road with a sunset in the background.

Today, in excess of 250 miles of National Trails Highway (Route 66) can be found in the County of San Bernardino and the County Department of Public Works maintains nearly 150 miles from Needles to San Bernardino as shown on our  interactive maps. And although Route 66 is no longer a main route across the country, it is a national treasure to be preserved and enjoyed for generations to come.

The information on this site pertains to the reach from the easterly edge of Barstow (Nebo Street) to the Mountain Springs Road/I-40 entrance. This section of the roadway has 128 timber bridges that were built more than eight decades ago, and all are displaying the negative impacts of many years of weather, flash floods, truck traffic, erosion, earthquakes, animal life and other factors. By reconstructing and rehabilitating the aging bridges, the safety, vitality, historical preservation, and accessibility of one of America’s greatest treasures will be reinstated.

A section of road that has collapsed due to water erosion.

It is critical to the entire length of the highway that the remaining 126 timber bridges on the alignment in San Bernardino County are rehabilitated or rebuilt in order to provide safe passage for the many tourists and open-road travelers from around the globe who come to this country to make the drive of a lifetime on such an historic roadway. The two fastest growing markets focused on heritage travel on the highway are China and Brazil. Every day, besides growing numbers of domestic travelers, visitors from throughout Europe, the Pacific Rim and the Americas can be found on Route 66. They contribute to the economic development of the businesses and communities along the way. Much-needed improvements will prevent additional road closures and eliminate recent weight restrictions to accommodate all modes of travel and the movement of goods.

This site provides information for several ongoing efforts to improve and restore the roadway.

National Trails Highway Bridge 77 Updates

Bridge 77 Reopened – March 22, 2024

On Thursday February 15, 2024 Caltrans notified San Bernardino County Department of Public Works that during a scheduled routine bridge inspections it was found that Bridge Number 77 on National Trails Highway between Amboy Road and Kelbaker Road was deficient and recommend immediate closure to all vehicle traffic. County Public Works staff immediately followed up on the Caltrans inspection and discovered that the structural pilings which hold up the bridge were degraded by 50%. Due to safety concerns for the traveling public County Public Works agreed with the Caltrans recommendation and immediately closed the bridge to all vehicular traffic.

The bridge is a wooden trestle bridge, built in 1930, making it a 94-year-old bridge. The wooden piles are exhibiting severe decay and deterioration which in turn has impacted its structural integrity. The deterioration has substantially compromised both the load-bearing capacity of the piles as well as the overall strength and serviceability of the bridge.

Construction of alternatives like a by-pass (shoofly) take time due to the requirements in obtaining environmental clearances from regulatory agencies. By the time these clearances would be received, and construction of a by-pass was completed, the ongoing repairs will be completed, and the bridge re-opened. County Public Works has provided alternative routes during the closure. Electronic Messages Boards indicating the alternative routes have been placed in various locations in the area and public notices have been placed on all social media as well as on the County Public Works Website. Public Works – Public Works (

The closure on NTH is from Bridge 70, on the Eastern edge of the town of Amboy, to Kelbaker Road.

Post inspection the following steps have occurred:

  • Dispatched staff for the closures and provided detour routes and information.
  • A structural engineer(s) reviewed the damage to the bridge.
  • Draft and approve plans to address repairs.
  • Obtained environmental approval and permits.
  • Locate and ordered all necessary materials and equipment.
  • Dispatched staff to begin the excavation of the site to being the repairs.
  • Excavate site (in progress)
  • Pour footings (the reinforced concrete that holds the pilings upright)
  • Add piles (new uprights) to support the structure.
  • Add additional structural supports to support the bridge structure.  

Public Works Status Updates:

February 15Caltrans notified San Bernardino County Public Works of bridge condition after routine inspection of the Sombra Ditch bridge was completed.
February 15Dispatched staff for the closures and provided detour routes and information.
February 22A structural engineering team assessed the damage to the bridge.
February 27Received plans from the structural engineers for the repairs.
February 27Obtained environmental approval and permits.
February 28Located and ordered necessary materials and equipment.
February 28Dispatched staff to begin the repairs.
February 28 – March 14Excavate site and dig footings    
February 28 – March 14Set rebar cages for footings.
March 15Pour footings (the reinforced (rebar) concrete that will hold the upright pilings)
March 18 – March 20Add piles (new upright supports) from footings to support the bent cap.
March 18 – March 20Add supplemental bent caps (this is the combination of the cap and pile). Together with other bents they will act as a support for the bridge.
March 21 Final inspection
March 22Bridge Reopened

Funding and Future Projects
Active and Completed Projects
Road Closures and Weight Restrictions
Environmental and Agency Coordination
Maintenance Projects

Additional Information

Contact us at: Department of Public Works Operations: 909-387-8040