Category Archives: County Highway

US 6 – Santa Clara River Bridge – A Closer Look

US Highway 6, now known as Sierra Highway, crossed the Santa Clara River near Solemint, California. The bridge it originally used, constructed in 1938, is planned to be replaced in the near future. This bridge is one of the oldest remaining in the Santa Clarita area and is the longest span on former US 6 in California. The bridge has remained almost intact from its original construction. The only changes have been minor to the bridge itself. The highway, however, has changed quite a bit. In 1968, Sierra Highway, then State Route 14, was widened to four lanes. A second bridge for northbound traffic was added, with the original bridge being used for southbound traffic.

Presently, Sierra Highway is six lanes wide at the river crossing. As the bridges were built with a four-lane highway in mind, only a narrow shoulder along both directions exists. This condition is one of the reasons the bridges across the Santa Clara River are being replaced.

In March of 2017, I took a trip to inspect in more detail the bridge and the surrounding area. It was nice to see the bridge again, as it brought back a lot of memories. I used to live near the bridge and crossed it almost daily. It will be sad to see it go as it is one of the last remaining pieces of the old highway. So, please, check it out yourself while you still can. I’m not quite sure when the construction will begin, it may have already.

Main Structure:

Side view, from the northern end. Note the small arches along each span.
Southern abutment and wing wall.
Between the 1938 and 1968 spans. Quite a difference between the girders.
Deck view, looking northerly from the south end.
Side view showing the railing, arched spans, and wing wall.

Detailing:

Underside view of the bridge.
Closeup of the west side railing from the south end of the bridge.
View showing the railing at the expansion joint.
Expansion joint that may have moved during an earthquake or from settling.
Expansion joint along the bridge deck.
Deck drain detail.
Remaining section of railroad rail and wire fence embankment protection.

Los Angeles County Survey Records

Los Angeles County Department of Public Works has a wealth of information available on their website. With a bit of patience and some looking around, you can find quite a few treasures using their mapping application. I’ve so far found the original survey data for the “Bridge To Nowhere” roadway, plans for other roadways that were never built in the Sierra Pelona Mountains, as well as the forest service permit for the Shoemaker Canyon Road that was never completed.

http://dpw.lacounty.gov/sur/landrecords/index.cfm

Image of the Week – 9/20/15

Top of Sherman Pass in the southern Sierra Nevada. Highest paved non-State highway in the range.
Top of Sherman Pass in the southern Sierra Nevada. Highest paved non-State highway in the range.

Highway Resources Page

I’ve recently added a new section to the socalregion website. I noticed the site was lacking in resources for local roadways. In particular, information on how to contact various local agencies for road projects, logs, and maintenance. With this in mind, I’ve added a new page to help others get their roads fixed and find out more information about those roadways. I’ve called it the “Southern California Highway Resources” page, which can be found on the Southern California Highways page and via this link.

Image of the Week – 7/11/15

Mulholland Highway and the Santa Monica Mountains just east of Kanan Dume Road. Looking northerly toward the Santa Susana Mountains.
Mulholland Highway and the Santa Monica Mountains just east of Kanan Dume Road. Looking northerly toward the Santa Susana Mountains.

Finding Old Highways – A Guide – Part 1

When looking for old highways, there are many clues you can use to help discover where old highways ran. This will serve as a partial guide to finding those clues and figuring out the history of a roadway in California.

State Highways

When you are looking for clues if a roadway you are on is an old State Highway, there are a few things to look out for. Depending on the age and location, look out for Right of Way monuments. In California, these are small concrete blocks with a C on the side of them, facing the roadway. They tend to be at the fence line along roadways, at the same distance as the utility poles, or further out. How much they stick out also varies. Some are just a few inches above the ground where others are about a foot high. Look out for these monuments at the beginning or ending of a curve usually about 50-100′ from the centerline of the roadway (or former centerline).

Old C-Block State Highway Right Of Way marker from 1930.
Old C-Monument State Highway Right Of Way marker from 1930.

Other clues tend to be tougher to spot but can be very subtle in appearance. Roadways that were formerly paved with concrete instead of asphalt are usually cracked in a very specific way if the asphalt is old enough. Expansion joints in the concrete, potholes exposing the old paving, or a defined crack running near the roadway edge usually give this away. Older concrete paving was either 15′, 18′, or 20′ wide. Modern roadways are usually 24′ wide, with two 12′ lanes. Look out for this concrete at curves which appear to have been straightened.

Original alignment of the Ridge Route at Tejon Pass. These lanes were built in 1923 on top of the original 1919 Ridge Route concrete.
Original alignment of the Ridge Route at Tejon Pass. These lanes were built in 1923 on top of the original 1919 Ridge Route concrete.

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On some roadways bypassed or abandoned after 1964, old postmile markers can be found. These markers are similar to the ones on current State Highways. On a current roadway with R mileage, look for old alignments in the area. R mileage indicates a realignment that took place after 1964, which is the point of “base mileage” for California State Highways.

This milepost was found near Whitaker Summit on old US 99. US 99 was gone legislatively in 1964 so Route 5 took over the numbering here. That is why it shows the mileage for I-5.
This milepost was found near Whitaker Summit on old US 99. US 99 was gone legislatively in 1964 so Route 5 took over the numbering here. That is why it shows the mileage for I-5.

Abandoned roadways are tougher to spot depending on the area climate. Drier climates tend to preserve older paving better than wetter climates. In some areas, the paving itself was removed after the roadway was bypassed. I have found a few sections of roadway relatively intact, complete with old striping, in Central and Eastern California. When the pavement has disintegrated or obliterated, you can look out for areas where there is less vegetation and distinct roadway grade. Sometimes old drainage culverts and bridges are left behind with nothing but dirt grade leading to them.

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More paving, both lanes now visible.
More paving, both lanes now visible.

In any area, make sure to take plenty of photos if you find an old alignment. You never really know when the local jurisdiction will come along and either obliterate or repave the roadway. This is fairly common in Los Angeles County as I have found. The most recent loss has been the June 1933 three lane concrete in Gorman along old US 99 which was repaved in the past couple years. Document what you find as best as you can. Doing so will help to preserve the memory of these forgotten roadways for many years to come.

Image of the Week – 3/9/15

St. Francis Dam site in 2006 from the reservoir side. The crumbling remains of the wing dam are visible on the ridge to the right.
St. Francis Dam site in 2006 from the reservoir side. The crumbling remains of the wing dam are visible on the ridge to the right.

March 12, 2015 will mark the 87th anniversary of the collapse of the St Francis Dam in San Francisquito Canyon, Los Angeles County, California. The collapse occurred just before midnight on March 12, 1928. It is still California’s second largest disaster in terms of lives lost. Approximately 500 people died in the ensuing flood which flowed to the ocean near Oxnard, CA along the Santa Clara River Valley. Only the 1906 San Francisco Earthquake and Fire exceeds the number.

Image of the Week – 2/16/15

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