All posts by Michael F Ballard

Michael F Ballard is the author and administrator of the Southern California Regional Rocks and Roads website, https://socalregion.com, since 1995. I have been studying the geology and highway history throughout southern California for most of my life. I am also the President of the Ridge Route Preservation Organization. Founder of the Historic Highway 99 Association of California, https://historic99.org .

Help designate US 99 in Bakersfield as historic!

There is a group in Bakersfield trying to get historic route signs posted on the original alignment of US 99 through the Bakersfield area. They could use your support. Check out the site below for more information.

https://www.gofundme.com/HistoricUS99Kern

What is a “C-Monument”?

Roadways and their rights-of-way are marked in various ways. Originally, roadway rights-of-way were poorly marked, and as a result, changed quite a bit. These changes made travel sometimes rather confusing as the roadway path may have changed before the map the traveler used changed. This sort of problem also cost the State quite a bit of money as they had to not only correct the problem, but also deal with the potential land costs of a new alignment.

Starting in 1913, the California Highway Commission came up with a plan to mark the right-of-way in a more permanent manner. Their solution – a “C-Monument”. While not the official name, which is simply “survey monument” or “right of way monument”, it aptly describes the marker. These monuments would be placed at the edge of the right-of-way at intervals along tangents (straightaways) and at curve points (BC and EC or Beginning of Curve and End of Curve). Optimally, these monuments would project about one foot above the ground with the C facing the roadway. The C stood for California, as in the California Highway Commission. At the top of the monument, a copper plug was placed to help guide surveyors. Per the January 1949 Division of Highways Standard Specifications manual, “Monuments shall be set firmly and vertically in the ground to a depth of at least three feet.”

Old C-Monument State Highway Right Of Way marker from 1930.
C-Monument along a 1930’s alignment of US 6 in Red Rock Canyon.

The C-monument was actively placed and used for many years, though when it finally was out of use seemed to vary between districts. In San Diego County in District 11, for example, they were used along freeways constructed in the mid to late 1950’s. Los Angeles County, within District 7, seemed to stop using them sometime in the late 1930’s. Today, the monuments that remain are still valid survey monuments. While not placed anymore, Caltrans, as well as local agencies, still use them. As such, please do not disturb or collect them if they are still in place.  Finding them along a roadway also doesn’t automatically make it an old State Highway. Some counties also used these monuments as they were a part of the standard plans for any project that involved state or federal dollars, such as Del Dios Highway between Lake Hodges and Rancho Santa Fe in San Diego County.

Finding these monuments is actually quite simple. Typically, roadway rights-of-way ranged anywhere from 100′ to more than 300′. Find a curve in the roadway you are looking at and look for one on either side of the roadway about 50 to 150′ away from the centerline of the roadway. In mountainous areas, the uphill one tends to be easier to spot than the downhill side. Fence lines, power lines, and other similar features can be used to indicate the right-of-way edge. As they can still be used today as survey monuments, some are marked with paddles or other objects to make a surveyors job easier when locating them. Placer County uses a white “R/W” paddle. Caltrans District 9, at least in Inyo County, uses orange poles as location markers.

Related Links:

Seeking Old Highways – A Guide

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.

Upcoming Highway Tours

While no dates are set as yet. I am planning to do two more tours in the next couple of months. The first tour will be in early October and will cover US 80 from San Diego to Ocotillo, unless temperatures are predicted above 90 F. After that, the next tour, sometime in early November, will cover US 99 from Newhall Pass to Grapevine. The accessible portion of the Ridge Route will also be covered, depending on the weather. Dates will be set in the next couple of weeks.