Category Archives: San Gabriel Mountains

Mt Wilson Observatory Geology Talk

Lectures

On Saturday, June 16, at 5:30 pm Mount Wilson Observatory will be hosting a talk by Dr. Tanya Atwater, professor emeritus of geology at UC Santa Barbara. Dr. Atwater played a major role in piecing together the plate tectonic history of our part of the planet. She will talk about how the motions of the Earth’s crust created the current topography of southern California (including the perfect site for astronomers to explore the Universe). The talk will be followed by a rare chance to look look through Mount Wilson Observatory’s 60-inch Telescope, which revolutionized telescope design and allowed astronomer Harlow Shapley to find our place in the Milky Way Galaxy. Tickets are only $20 and proceeds will all go to the maintain the Observatory.

Image of the Week – 8/27/2017

Looking toward Timber Mountain with Mt San Antonio and Cattle Canyon to the left.

Trip to the San Gabriels

From Thursday to Saturday this week, I shall be touring the San Gabriel Mountains on my motorcycle. My plan, thus far, is to check out the roads around Lytle Creek, San Gabriel Canyon, Glendora Ridge, San Antonio Canyon, Angeles Crest Highway, Angeles Forest Highway, San Dimas Canyon, and much more. The trip should be a lot of fun, even though just the paved roads will be covered. There is always much to explore in Southern California.

Image of the Week – 4/2/2017

Hiking to the Bridge to Nowhere with my husband while in a wetsuit

Image of the Week – 10/18/2016

Looking south toward the south closure on Hwy 39.
Looking south toward the south closure on Hwy 39.

Sand Fire Information

As the Sand Fire has grown quite substantially in the past few days, it has become more difficult to track where it is going. I’ve found a couple of good links for up-to-date information on this fire. Map below courtesy of the Los Angeles County Fire Department.

Image of the Week – 11/29/2015

Out in Rancho Cucamonga inspecting the Sierra Madre Fault.
Out in Rancho Cucamonga inspecting the Sierra Madre Fault.

Image of the Week – 2/16/15

Mt Baldy Road, Lower Tunnel. Built in 1949.
Mt Baldy Road, Lower Tunnel. Built in 1949.

Image of the Week – 11/1/14

On the trail to Mt San Antonio along Devils Backbone.
On the trail to Mt San Antonio along Devils Backbone.

Road Building in San Gabriel Canyon

In the 1930’s, Los Angeles County began construction of an additional roadway over the San Gabriel Mountains via the East Fork of the San Gabriel River. About half of the roadway, complete with with four larger bridges and a tunnel, was constructed. Work had progressed as far as “The Narrows” by 1938. However, the March 2-3, 1938 storms caused much of the roadway to be washed out. The project was then abandoned, leaving a large arch bridge stranded many miles upriver. The tunnel still exists as well, just north of the “Bridge to Nowhere”, though it has been sealed at both ends.

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1936 arch bridge – The Bridge to Nowhere
1936 stamp on the arch bridge.
1936 stamp on the arch bridge.
Looking over the arch bridge to the tunnel site.
Looking over the arch bridge to the tunnel site.
Abandoned and partly destroyed bridge over the river.
Abandoned and partly destroyed bridge over the river.
Bridge over Cattle Canyon on the East Fork Road. This is similar to what the removed bridges north of here would have looked like.
Bridge over Cattle Canyon on the East Fork Road. This is similar to what the removed bridges north of here would have looked like.
1934 USGS Camp Bonita map showing the roadway completed to about 1 mile south of the “Bridge to Nowhere” site.
1940 USGS Camp Bonita map showing the now stranded bridge location.

In the 1955,  a new road building project commenced in the canyon. This new alignment would stay high above the canyon floor until it got nearer to the “Bridge to Nowhere”, allowing that earlier work to come to some use. Progress on this roadway was slow, mostly due to poor funding. Convict labor was used for most of the project, similar to many other road building efforts at the time in Los Angeles County. Two tunnels were constructed as well. These still exist and are mostly intact. This project too was cancelled in the late 1960’s, leaving another large scar in the canyon. This road is presently known as Shoemaker Canyon Road.

Stone railing along Shoemaker Canyon Road.
Stone railing along Shoemaker Canyon Road.
Looking toward the higher peaks of the San Gabriels along Shoemaker Canyon Road.
End of the pavement and open section of Shoemaker Canyon Road.
End of the pavement and open section of Shoemaker Canyon Road.
1961 and 1964 tunnels in view.
Partly graded roadway and tunnel along the "Road to Nowhere".
Partly graded roadway and tunnel along the “Road to Nowhere”.
Date stamp on the first tunnel.
Inside the longest tunnel, from 1961.
Grading along the "Road to Nowhere".
Grading along the “Road to Nowhere”.
Northern tunnel from 1964.
Northern tunnel from 1964.
1966 USGS Glendora map showing the “Shoemaker Canyon” roadway under construction.

Today, the canyon is protected from future development through the Sheep Mountain Wilderness Area. Even without this protection, the geology of the canyon makes for a very expensive project. Maintenance would also be costly, as seen with State 39 through San Gabriel Canyon and above Crystal Lake. In time, all these structures and cuts will wash away, leaving the canyon with only bits of concrete and asphalt to show what was once here.

Remnants of paving in the canyon.
Remnants of paving in the canyon.