Mosquito Road Bridge hits major milestones
Since breaking ground in July 2022, the Mosquito Road Bridge project has made significant progress above the South Fork of the American River. The new 1,200-foot-long concrete span will replace the narrow, one-lane timber suspension bridge built in 1939, eliminating long-standing weight and safety limitations while providing a modern two-lane crossing for the Mosquito and Swansboro communities.
The $93 million project is funded through the federal Highway Bridge Program and was awarded to Shimmick Construction Company, Inc. in May 2022. Designed to meet current safety and load standards, the bridge represents a major infrastructure investment for El Dorado County.
Construction efforts in March and April focused on Pier 2 and Pier 3, massive vertical support rising from the canyon walls. Crews completed complex upper stem and pier tables concrete pours following months of formwork, rebar installation, and preparation work. A key milestone was reached on April 23 with the successful placement of Pier 3’s upper pier tables, with Pier 2’s final placement scheduled shortly thereafter.
With pier table construction nearing completion, crews began preparing for balanced cantilever construction using form travelers. This method allows the bridge deck to be built outward from each pier and is critical for spanning the deep, rugged gorge.
To support this phase of work, El Dorado County implemented a 10-week closure of Mosquito Road from late May through early August 2025. During the closure, crews completed drainage work, crane inspections, and multiple concrete pours, while traffic was rerouted via Rock Creek Road. County DOT maintenance teams also performed patch repairs on Mosquito Road, Mosquito Cutoff, and Rock Creek Road as conditions and funding allowed.
Although the bridge was originally expected to open in late 2025, completion is now projected for June 2026. Final paving near the bridge will follow construction, and the County continues to pursue funding for future roadway improvements. Once the new bridge opens, the historic 1939 suspension bridge will be preserved for pedestrian and bicycle use, honoring the area’s history while supporting its future transportation needs.
Recent developments
From late 2025 through early 2026, construction crews made steady progress on key bridge components, including piers and abutments, completing multiple segments while initiating new ones each month despite some delays due to weather and holidays. Work included installing bearings, constructing temporary support structures (falsework), and placing concrete to form the bridge. Throughout this period, the team also maintained compliance with environmental regulations by monitoring water quality and controlling erosion.
Looking ahead to spring and early summer 2026, planned activities include completing additional bridge segments, constructing approach slabs, installing safety rails, and finalizing major structural connections.
More to come, keep following along!
