Category Archives: Los Angeles County

Road Building in San Gabriel Canyon

In the early 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. The road, then known as the Camp Bonita – Prairie Fork Road, was about half complete with with four larger bridges and a tunnel, by early 1938. 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, first known as East Fork Road, then Shoemaker Canyon Road. 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 1976 , 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.

M5.1 Earthquake hits La Habra

From the USGS – Updated:

http://earthquake.usgs.gov/earthquakes/eventpage/ci15481673#summary

intensity

lahabraci15481673_ciim

Event Time

  1. 2014-03-29 04:09:42 UTC
  2. 2014-03-28 21:09:42 UTC-07:00 at epicenter
  3. 2014-03-28 21:09:42 UTC-07:00 system time

Location

33.919°N 117.944°W depth=7.5km (4.6mi)

Nearby Cities

  1. 1km (1mi) S of La Habra, California
  2. 4km (2mi) W of Brea, California
  3. 5km (3mi) NNW of Fullerton, California
  4. 6km (4mi) E of La Mirada, California
  5. 546km (339mi) W of Phoenix, Arizona

Tectonic Summary

A M5.1 earthquake occurred at 9:09PM on March 28, 2014, located 1 mile easy of La Habra, CA, or 4 miles north of Fullerton, CA. The event was felt widely throughout Orange, Los Angeles, Ventura, Riverside, and San Bernardino counties.  It was preceded by two foreshocks, the larger of M3.6 at 8:03pm.  The demonstration earthquake early warning system provided 4 second warning in Pasadena.

There have been 23 aftershocks as of 10:00PM on March 28, the largest of which was a M3.6 at 9:30PM, and was felt locally near the epicenter. The aftershock sequence may continue for several days to weeks, but will likely decay in frequency and magnitude as time goes by.

The maximum observed instrumental intensity was VII, recorded in the LA Habra and Brea areas, although the ShakeMap shows a wide area of maximum intensity of VI. The maximum reported intensity for the Did You Feel It? map was reported at VI in the epicentral area.

This sequence could be associated with the Puente Hills thrust (PHT).  The PHT is a blind thrust fault that extends from this region to the north and west towards the City of Los Angeles.  It caused the M5.9 1987 Oct. 1 Whittier Narrows earthquake.

Previously, the M5.4 2008 Chino Hills earthquake occurred in this region.  It caused somewhat stronger shaking in Orange County and across the Los Angeles Basin.

The moment tensor shows oblique faulting, with a north dipping plane that approximately aligns with the Puente Hills thrust.

The demonstration earthquake early warning system provided 4 second warning in Pasadena.

Related Links

Angels Flight in Los Angeles

Angels Flight is a short funicular railway in downtown Los Angeles. It has been around since 1901, though not continuously. It used to run from Hill St and 3rd St west up Bunker Hill. It was moved about 1/2 block south about 15 years ago. I took this video of it in 2010.

My contribution to the Los Angeles Metro Rail System

Before the Metro Gold Line Eastside Extension was opened, I was contacted by Nobuho Nagasawa. She was commissioned to create the artwork for the 1st St and Soto St Metro Gold Line station. She was looking for maps of the area surrounding the 1st / Soto station and found my website on the East Los Angeles Interchange. After searching my collection, I did find two maps that covered that area. The Los Angeles and Alhambra 6′ map sheets from the late 1920’s covered the area she needed with the right resolution. They were then scanned in at high resolution and sent along to her for use. As they were USGS maps, they were within the public domain and easy to transfer.

As I had obtained the maps from a geologist that had marked them up, cleaning them up prior to scanning was essential. I got most of the marks off, but some still remained. It seems they were just enough to “watermark” the maps as indeed from my collection. While not intentional, it did help me identify the maps when I saw them in a video on the opening of the line. In December 2009, I was finally able to see the station in person. The sheer size of the artwork created from these maps was astounding. A portion of a 6′ USGS quad sheet had been transformed into a 30′ x 60′ map going from one side of the station to the other.

The "original" and the artwork. Map sheet being held is the Los Angeles 6' map.
The original and the artwork. Map sheet being held is the Los Angeles 6′ map.
Overview of part of the artwork display. Stairs lead to the platform level.
Overview of part of the artwork display. Stairs lead to the platform level.
Western half of the map showing the Los Angeles River and part of downtown.
Central portion of the artwork.
Closeup showing some of the marks left on the map. Note the “36” circled in pencil.
Markings for Pliocene Rock (PLIO) and a fault line.

I wish to thank Nobuho Nagasawa for allowing me the privilege of contributing to the Los Angeles Metro Rail system. It gives me great pleasure to know that something I have in my collection is seeing use in a way I never expected.

Long Rides Getting Longer…

It seems I have to redefine what a short ride is for me lately. I’ve been gradually increasing my distance record over the past three years. Sometimes I increase my record by only a few miles, sometimes by a whole lot more.

On May 7, 2011, I took the train to Los Angeles Union Station, and rode home. Downtown Los Angeles and my home in San Diego seem so far apart. They are about 110 miles apart, along the 5. The route I took, which I felt was the easiest and safest route, was 154 miles in length. San Diego may be southeast of Los Angeles but I started my ride heading west. Seems odd to go the opposite way to my destination, but it was the best way. I’ve found a really nice and fast route west from Downtown LA to Mid-City (Vineyard Junction, or for those non-Pacific Electric knowing folk – San Vicente Blvd and Venice Blvd). Past that, the options open up. On that ride, I followed Venice Blvd to Overland Ave, then to the Ballona Creek Trail. It proved to be a good way to bypass a large swath of city in a fast and efficient way. Once at the coast, I took the South Bay Trail down to Redondo Beach. That trail can be quite fun to ride, with all the distractions of the hot surfer boys in their wetsuits to watch!

After Redondo Beach, I followed Palos Verdes Drive North, then around the harbor, and into Long Beach. From Long Beach, I followed the coast the rest of the way down. The ride got more interesting and more tiring through Laguna Beach, with all those rolling hills. Things did look up though, as I found $80 alongside the roadway not long after taking a break just south of Laguna Beach. Sometimes, it does pay to bicycle! It did add a bit of brightness to my day, as the last few miles had been less than fun. Just too much traffic, and too narrow a roadway. Beyond that, there were a few more rolling hills, and San Clemente. At least that town could be avoided, quite nicely too. The signed bike route has sharrows and bike lanes. It can be tougher to follow at the north end, but overall, a good route. Just past San Clemente was San Diego County. So, goodbye Orange County, hello San Diego County!

I kept a good pace most of the route south, stopping in Oceanside for some food. It got dark around Torrey Pines, but most of the ride was over by then. I finally got home right about 8:30pm, tired, a bit sore, but quite happy. It was a long ride, but my next would be even further. I had a 200 mile ride in the works for the end of May.