Published May 14, 2026 3:25 pm
Mountain Tunnel Project construction map—STF map
Sonora, CA – A temporary forest road closure for the Mountain Tunnel Project road improvements is in effect until the end of the year.
Stanislaus National Forest officials say, “Due to the nature of the work, maintaining the road open would place the public at risk.”
The temporary closure of Forest Service Road 1S28B runs from May 13, 2026, through December 31, 2026. The road will be closed from the intersection of Forest Road 1S28 to its end. The San Francisco Public Utilities Commission is working on the project to improve access roads, which includes rock scaling, vegetation clearance, road surface and drainage maintenance, and the construction of rock fencing/netting.
“This is preparatory work for the construction of an adit (a nearly horizontal passage driven from the surface into a mine for access, drainage, or ventilation) and shaft into Mountain Tunnel near the existing South Fork Adit,” relayed forest officials, adding, “The order may be partially or wholly terminated prior to December 31, 2026, if the project is completed before then.”
Written by Tracey Petersen.
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