Caltrans cleared for nighttime SR‑1 borings to inform fish‑passage bridge design; Sherwood Valley tribe raises notice concerns

Caltrans will be allowed to conduct five geotechnical borings at two locations along State Route 1 after the Mendocino County Coastal Permit Administrator approved a coastal development permit on June 12, 2025.

Staff planner Mark Klieser said the work covers one drill site at Post Mile 4.64 near Fish Rock Gulch/Anchor Bay Campground and two sites at Post Mile 58.78 approximately 1 mile south of Fort Bragg near Tragoning Drive. The borings, each up to about 100 feet deep, are intended to assess subsurface conditions for foundations for free‑span bridges that will replace culverts blocking fish passage, Klieser said. Work will take place in Caltrans right‑of‑way, with no permanent development proposed, and Caltrans told the administrator it will minimize vegetation removal and restore disturbance after sampling.

Why it matters: The borings will inform bridge foundation design for projects meant to restore fish passage on coastal streams along one of Mendocino County’s primary coastal highways. County staff concluded the investigation qualifies for a categorical CEQA exemption for information collection and recommended approval with standard permit conditions.

Key details from staff and Caltrans

- Number and depth: Caltrans described five borings in total, up to roughly 100 feet deep. - Locations: Post Mile 4.64 (Fish Rock Gulch/Sunset Drive/Anchor Bay Campground approach) and Post Mile 58.78 (near Mendocino Botanical Gardens/Tragoning Drive). - Methods and timing: Drilling is planned at night between 8 p.m. and 6 a.m., with one‑way traffic control and required night lighting; drill rigs will be demobilized and parked offsite at the end of each shift. - Environmental protections: Caltrans submitted a spill prevention and response plan and a biological resources memorandum concluding a “no effect” determination for sensitive resources at the selected locations; borings will be backfilled or covered to prevent wildlife entry. - Tribal and agency coordination: Caltrans representatives said they performed additional cultural review for the larger bridge‑replacement project and that accidental‑discovery protections will be conditions of the permit.

Public comment and agency response

Valerie Stanley, Tribal Historic Preservation Officer for the Sherwood Valley Band of Pomo Indians, said the tribe did not receive notice of the project and expressed concern about the depth of drilling. Steven Umbertus, Caltrans project representative, said Caltrans would have its cultural team contact the tribe and noted that the schedule presently anticipates drilling in August, which allows time for consultation before mobilization. The staff report and Caltrans materials indicate the work is planned primarily within the paved roadway to minimize impacts.

Decision and next steps

The Coastal Permit Administrator approved the permit as recommended by staff, subject to the findings and conditions in the staff report. The permit is appealable to the California Coastal Commission; staff noted standard appeal windows apply and that the permit will be final if no appeal is filed within the appeal period.