Big Oak Flat Road – Yosemite National Park CA


The present Big Oak Flat Road was constructed by the Bureau of Public Roads (BPR), with Public Works Administration (PWA) funding, between 1935 and 1940.  It is one of  three main roads into Yosemite Valley, along with El Portal road and Wawona road.

Big Oak Flat Road is the main entrance road into Yosemite from the north, designated as state highway 120. At Crane Flat, highway 120 follows the Tioga Road toward Tuolumne Meadows and over Tioga Pass.  Big Oak Flat road splits off to head south toward Yosemite Valley.  Highway 120 from Groveland (west of the park) to the park entrance was constructed by the California State Highway Department in the 1920s and early 1930s, with federal assistance.  We are uncertain just how far that work advanced into the park before the New Deal arrived.

In 1933, planning began for a new Big Oak Flat Road to replace a barely-passable 19th century wagon road, which is now a hiking trail that can still be difficult to follow.  Construction began in 1935 and presented many challenges, as great effort was taken not to deface the cliffs of the Merced River canyon.  The result is one of the most scenic roads in America (now a National Scenic Byway).

Where Big Oak Flat Road descends into the canyon along sheer granite cliffs, it required three tunnels, three open-spandrel arch bridges over creeks, and many sections of roadway cantilevered over the cliff face. Looking at the road from the opposite side of the Merced River Canyon, one can see that much of it rests on thin air.  Along the road are lovely granite guard walls along the outside lane and retaining walls along the inside lane to hide road cuts.  The tunnels have rock work arches at each entrance.

A big opening ceremony was held in June 1940.





Source notes

John Broesamle book manuscript 2022.


Project originally submitted by John Broesamle on February 10, 2022.
Additional contributions by Richard Walker.

We welcome contributions of additional information on any New Deal project site.


Location Info

Yosemite National Park, CA 94389

Location notes: Pin drop along the main descent into Yosemite Valley

Coordinates: 37.743453, -119.76099

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