Recommended by Ricochet Members Created with Sketch. California History: The Ridge Route

Grapevine Grade looking north of original Ridge Route. Note this is Tejon Pass, not Tehachapi Pass


Early in my engineering career, I used to drive what was and still is colloquially called “the grapevine” to and from work every day for about five years. In fact, I rarely did drive the actual grapevine. I lived in Castaic , which is located in Los Angeles County at the southern end of the Tejon Pass, and worked on construction projects in the Gorman area and so drove I-5 “up the hill” and “down the hill” between these two points. The grapevine is the name for the grade at the northern portion of the Tejon Pass, which is in Kern County and connects Los Angeles with northern California.

In any event, back then I spent a portion of my free time investigating the history of the area and found out that the I-5 route over the Tehachapi Mountains I drove every day had been preceded by two previous routes, the first of which was considered an engineering marvel of its time. It turned out that I lived “just down the street” from the southern end from that first route – The Ridge Route – and I drove, bicycled and walked it a number of times and found what I could about it in local libraries. It’s been a long time since I lived in the area; but, I recently came across a couple of books which greatly increased my knowledge of the subject. Those books are Highway 99 by Stephen H. Provost and Ridge Route: The Road That United California by Harrison Scott. Scott, a retired engineer, spent years researching, studying and driving the Ridge Route. He also spent years working with federal officials to get that portion of the Ridge Route within the National Forest added to the National Register of Historic Places. Here is his website.

The Ridge Route and its successor routes over the mountains is an interesting story (or at least I think so) and I thought I’d briefly discuss a bit of that history here at Ricochet. The story will proceed in three parts. First, a brief history of the engineering and construction of the various routes over the mountains followed by a brief discussion of a few points of interest along the route and finally end with a short discussion of another important piece of infrastructure which further binds together northern and southern California.

The Ridge Route

LA Times Map of Ridge Route 1915


There are significant geographical barriers between northern and southern California. Namely, a series of east-west mountain ranges called the transverse ranges with few passes, none of them easy, thus preventing easy passage between the San Joaquin Valley and the Los Angeles area. By 1909, the State of California got serious about building a highway network throughout the state to allow for automobile traffic between towns. The state passed a bond measure of $18 million to begin this network including a route to connect the San Joaquin Valley to Los Angeles.

The California State Highway Commission was responsible for the design and construction of these various roads including what would become the Ridge Route. At the time, there were no all-weather roads between northern and southern California. All that existed were two railroad routes – the first the Southern Pacific (SPRR) route over the Tehachapi Pass and it’s unique Tehachapi Loop. The other was a coastal SPRR route between Los Angeles and San Francisco, which was completed in 1901. In planing for the new road, the Commission looked at several different routes. One was to follow the SPRR route over the Tehachapi Pass and continue south to Lancaster and then proceed via either Mint Canyon or Bouquet Canyon. Another was to proceed up the Grapevine and over the Tejon Pass, then turn east to Quail Lake, which is just south of Gorman (the modern-day Highway 138) and then head south via the San Francisquito Canyon. A third potential route also proceeded up the Grapevine and over the Tejon Pass, but rather than proceed east to Lancaster, it would instead continue south through the Piru Gorge to Castaic. The fourth route, and the one eventually chosen, also proceeded up the Grapevine and over the Tejon Pass. However, after passing Gorman it would follow the mountain ridge line until it reached Castaic.

The aptly named W. Lewis Clark, a State Highway Commission engineer, was responsible for the route’s final alignment. The proposed route was broken into three contracts, each approximately equal in length, and put out to bid. State Highway Commission engineer N. D. Darlington oversaw construction. Work started in 1914 and was completed in October 1915.

The completed road was 20 feet in width and originally received a surfacing of oiled gravel. Later, from 1917-1921, the road was paved with a 20′ wide, 4″ thick layer of portland cement concrete which was reinforced transversely with a 3/8″ steel reinforcing bars 18″ on center. The design specifications called for a minimum curve radius of 70′ and, since the route followed the ridge line as much as possible, the road was very curvy. Between Castaic and Grapevine, there are over 700 curves with a total of 39,441 degrees of curve meaning that someone driving the route had to go around in a complete circle 110 times! Wheee, I’ll bet there were more than a few dizzy drivers! The work required about 1,000,000 cubic yards of excavation, the majority of which was performed with horses or mules pulling Fresno scrapers. The largest cut on the job was the 110 foot deep Swede’s Cut which was performed with a steam shovel. The overall cost for the Ridge Route was about one and a half million dollars.

Ridge Route Tour Map


As soon as the road was opened to the public, two things happened: First, the public took immediately to the new road. Trucks began delivering produce, construction materials and just about anything else to and from Los Angeles, and individuals took to the road both to travel to other parts of the state or as a weekend outing. This was not surprising as the new road shortened the trip between Bakersfield and Los Angeles by 45 miles. Bakersfield to Los Angeles could now be traversed in “only” 12 hours (today, it’s about a 2-hour drive depending on traffic). Secondly, a variety of businesses sprang up along the route to cater to the needs of the motoring public. Most of these businesses consisted of a diner and/or a restaurant, a gas pump or two, cabins or rooms for rent, camping spaces, and someone who at least called himself a mechanic available. A cabin or room with running water generally went for $2 dollars, a camping space 50 cents and 75 cents for a meal. The tour map posted above shows most of these enterprises.

Despite its popularity, the narrow, curvy road was very dangerous, and accidents and fatalities were a common occurrence. It did not help that fill slopes either had no protective guard railings or had wooden fences which worked about as well as you’d expect. A speed limit of 15 miles per hour was strictly enforced along the route, while the most numerous vehicle of the time, the Ford Model T, had a hard time making 15 mph going up the numerous grades along the way, but also had trouble keeping below 15 mph going down those same grades. The most dangerous curve was called “Deadman’s Curve” and is still visible from the freeway today (it is just to the east of the southbound lanes and 1/2 mile north of Fort Tejon).

Deadman’s Curve


Traffic counts on the road continued a steady increase – by 1925 more than 2,000 vehicles per day used the road which was beyond its capacity. In addition, car performance was improving, the 20 HP Model T would shortly be replaced with the 40 HP Model A. State Highway Department engineers began planning for an alternate route over the mountains to take the pressure off of the Ridge Route and in 1933 the Ridge Route Alternate was opened to traffic. The alternate was a vast improvement over the Ridge Route. In the Alternate, about 80% of the curves were eliminated, the minimum curve radius was increased to 1,000 feet and the length of the passage was reduced by about nine miles. It was designed for a capacity of 12,000 vehicles per day versus the 1,500 vehicles per day of the original route. The south portion of the Alternate continued south through Piru Gorge rather up along the ridgeline. By this time, the work was performed with modern earthmoving equipment, gasoline or diesel-powered scrapers, dozers, shovels and trucks with a total cost of $3.5 million. As per the it’s name, engineers expected the Ridge Route Alternate to serve that purpose, an alternate to the Ridge Route to be used mainly by truckers, salesman and the like with Sunday drivers still expected to make use of the original Ridge Route. However, that did not happen. Immediately, all used the new Alternate and business on the original route south of Quail Lake quickly dried up with most businesses closing within a year or two of the Alternate’s opening. Because of this, little is left of those establishments on the southern portion of the Ridge Route except for foundations.

Postcard of Ridge Route near Sandberg’s


Swede’s Cut
Tumble Inn Restaurant and Hotel circa 1926


Tumble Inn today


Car hits a “guardrail” on Ridge Route ca 1920


1920’s postcard of Ridge Route


Ridge Route horseshoe bend


Getting back to the Ridge Route Alternate, it was built with 3 lanes, one in each direction and a middle “passing lane”. At least that’s what the engineers called it. It quickly came to be called “the suicide lane”. And, it lived up to that name. Although the road was better engineered than the old route, the suicide lane led to accident and death totals that weren’t much better than that old curvy road. Due to the unacceptable accident rate and the ever-increasing use of the Alternate, the State was in the process of widening the new road to four lanes when World War II would delay that work for the duration.

Ridge Route Alternate in Piru Gorge 1934


Ridge Route Alternate near Grapevine ca 1937


Postcard of Ridge Route Alternate circa 1940


After the war, California passed the Collier-Burns Act of 1947 which provided a long-term funding system for state highway construction and these funds were rapidly put to use in widening the 3-lane Ridge Route Alternate to a four-lane expressway which was completed in 1952. Of course, California’s population continued its post-war boom and the expressway needed to be replaced with an 8-lane interstate freeway to meet the continued demand. That construction occurred between 1960 and 1970 in phases so as to keep the road open to traffic at all times. The alignment for the new interstate closely follows that of the 1952 Golden State Highway except for the need to around the Piru Gorge area which was submerged under the waters of Pyramid Lake, a recently constructed facility of the State Water Project (SWP). A table is provided below which provides some of specifications for each of the four routes discussed above.

Item ………. RR 1915ARR 1933 .. GSH99 .. I-5 1970

Compl Date 1915……… 1933……….. 1952…..1970

Lanes ……….2 ……………3 …………….4……… 8

Lane Width .10’ …………10’ ………….12’……. 12’

Pavement ….pcc …………pcc ………….pcc ……pcc

Median ……..No ………….No ………….Yes …..Yes

Shoulder …..No ………….Yes …………Yes …..Yes

Max Grade ..7% ………….6% …………6% …..6%

Summit ……4233’ ……….4183’ ……..4183’ ..4144’

Min Curve R .70’ …………1,000’ …….1,000’ ..3,000’

Length ……49 miles …….40 miles ….40 miles .40 miles

Cost ……..$1.5 M ………$3.5 M …….$13.5 M .$103 M


  1. Column 1 refers to original Ridge Route (RR 1915), while column 2 refers to the Ridge Route Alternate (ARR 1933), column 3 refers to the Golden State Highway (GSH99) and column 4 refers to Interstate 5 (I-5 1970).
  2. pcc = portland cement concrete
  3. Min Curve R = minimum curve radius. The shorter the radius, the tighter and more severe the curve, while the longer the radius the shallower and more gentle the curve.

In 2003, Huell Howser dedicated one of his Road Trip programs to the Ridge Route in which he toured the route with Harrison Scott. It’s no longer available on line, but you can watch it (or any other Huell Howser program) at the Chapman University website of Huell Howser’s archives. I’ve linked to it here. It’s about 45 minutes in length. If you have the time and have an interest in the topic, it’s well worth watching.

On the 100th anniversary of the opening of the Ridge Route, the Bakersfield Californian took a tour of the route with Harrison Scott and issued an 11-minute video of that tour. It’s not as good as the Huell Howser video, but it’s still good and worthwhile.

Points of Interest

In this section, I’ll mention a few points of interest along the Tejon Pass from Castaic in the south to Grapevine in the north.

Castaic came into being with the Ridge Route in 1915. It was the southern terminus of the Tejon Pass crossing in 1915 and has remained the southern terminus through each of the new roads over the pass. When I lived there, it was not much more than a large truck stop. Today, it’s a bedroom community for Los Angeles and the San Fernando Valley. One thing I did not know until recently is that it was the site of a long-standing honest-to-goodness range war. A land dispute between two ranchers, William Jenkins, and William Chormicle, raged and simmered off and on for the better part of two decades with a body count in the double digits. Today, most of the land in dispute is beneath Castaic Lake, also a facility of the State Water Project.

The 5-Mile Grade is somewhat unique among interstate freeways. Five-Mile Grade is the name given to the northbound grade up the hill as I-5 passes Castaic, and this stretch of northbound traffic is to the left of the southbound traffic, which is a very unusual arrangement. Five-Mile Grade shares the alignment of the previous two roads (Ridge Route Alternate and Golden State Highway). The northbound Five-Mile Grade is a bit steeper than the newer southbound descending grade to it’s right (east). Engineers chose this alignment during the design of I-5 as they were more concerned about the dangers associated with potential brake failures for descending eighteen-wheelers than with the additional fuel consumption that would be required for the ascending vehicles. If you ever drive this grade be sure to look for the truck escape route pointing in the wrong direction about half way up the grade which was left as is during construction.

In and of itself, Templin Highway is not of much interest and I imagine most people driving over Interstate 5 ever give it a moments thought. However, for anyone interested in Ridge Route history it is important as a means of access to the earlier roads. Taking the off-ramp to the east leads to an intersection with the original Ridge Route, while taking the off-ramp to the west leads to a preserved portion of the four-lane Golden State Highway which exists up to just south of Pyramid Dam. It should be noted that this stretch of the Golden State Highway also follows the alignment of the Ridge Route Alternate.

Kinsey Mansion


The original Ridge Route followed the alignment of the current Highway 138 starting a mile or so east of Quail Lake and the proceeded towards Gorman via what is called the Gorman Post Road. The lake was long existing at the time of the Ridge Route construction having been created by a cataclysmic movement of the San Andreas Fault ages ago. However, during construction of the State Water Project, a dam was added at the site and the lake was incorporated into the SWP in 1967 as the most cost efficient way to cross the fault. Directly across Highway 138 from Quail Lake is a large, picturesque Georgian Mansion known as the Kinsey Mansion. It looks completely out of place and the scuttlebutt among the locals was (and probably still is) that the mansion was used in the classic movie Gone With the Wind as the mansion Tara. That’s not so though as Mr. Kinsey did not complete his mansion until 1946.

Speaking of the San Andreas Fault, it is a factor that needs to be taken into consideration for any large construction project such as the freeway or the SWP facilities. The fault crosses I-5 several times before heading towards the southeast and Palmdale and Littlerock. This link will take you to several photos of the fault in this area. I’ll have a little more to say about the fault a bit later.

Getting back to the Ridge Route alignment, following the Gorman Post Road takes you into Gorman. Gorman has been a stopover along the Tejon Pass since at least the 1850s. The most interesting thing about Gorman; however, is that the entire town is owned by the Ralphs family, who established and still own the Ralphs Market grocery chain. In 1994, the Ralphs reportedly put the entire town up for sale for $13.6 million, although my understanding is that they still own the town. One thing I should note is that from Gorman north there a number of locations where one or more of the earlier roads still exist. This is the case in and around Gorman, the Frazier Park interchange area, Lebec and Fort Tejon.

Gorman circa 1955


Dec. 16, 1940 hundreds of motor vehicles halted at Gorman by snowstorm


A couple of miles north of Gorman is the Frazier Park off-ramp. Frazier Park and several other small communities are several miles west of I-5 and it is in these communities where the majority of year around residents in these mountains make their home.

Another couple of miles north takes us to Lebec. Lebec was home to the poshest hotel along the original Ridge Route – The Hotel Lebec – although it went by several different names over the years, Lebec Lodge, Hotel Durant (named for its owner at the time Cliff Durant, the son of Will Durant of General Motors notoriety), among others. Over the years the hotel hosted its fair share of the rich and famous including Clark Gable and Carole Lombard, Charles Lindbergh and his bride, Anne Morrow, Buster Keaton, Jack Dempsey, Fatty Arbunkle and Bugsy Siegel. The hotel went through a series of owners over the years and after 1940 or thereabouts it began a slow, steady decline which led to its eventual condemnation and demolition in 1968.

Hotel Lebec postcard


Fort Tejon State Historical Park, which is open daily, is the site of Fort Tejon, a U. S. Army outpost that was in existence between 1854 and 1864. The fort was damaged by the 1857 Fort Tejon earthquake, an earthquake estimated to be a magnitude 7.9. In fact, the epicenter of the quake was about 120 miles to the northeast along the San Andreas Fault near the current town of Parkfield, CA. It was just that this portion of California was lightly populated at the time and Fort Tejon experienced the most damage that it came to be called the Fort Tejon earthquake. Incidentally, Parkfield is the most seismically active locale in California experiencing a 6.0 or greater earthquake once every 22 years on average.

Finally, we’re at the Grapevine, the north end of our journey! There is a general misconception that the Grapevine moniker refers to the twisting nature of the various roads and routes through the canyon and up the hill. That is not so. Grapes have grown naturally in the canyon for quite some time. In fact, it got its name from Don Pedro Fages, the acting governor of Alta California, who noticed the native wild grapes named the place Canada de Las Uvas, or grapevine canyon. At the Grapevine Grade, the north and south bound lanes maintain their proper alignment, as opposed to the south of Five-Mile Grade, discussed earlier. At both grades, though, it is not unusual to catch of whiff of burning brakes. The southbound lane is the older of the two embankments – it was the alignment for the 1933 Alternate route and is steeper than the new grade constructed for the descending northbound lanes. This was done for the same reason as at the 5-Mile Grade; a brake failure to a descending vehicle, especially a large tractor-trailer is less likely on a gentler slope.

Grapevine Canyon 1947


California State Water Project

There are several SWP facilities visible from this section of I-5; but, rather than mentioning them with the other points of interest, I thought it deserved it’s own brief section.

In California, most of the precipitation occurs north of the San Francisco Bay-Delta, but most of the population and irrigated agriculture occurs south of the delta. The main purpose of the SWP is transport some of what would otherwise be excess water to where it is most needed. The most challenging portion of the project was determining a method to get the water over or past the mountain ranges that separate northern and southern California. This was accomplished via a large pumping plant, the A. D. Edmonston Pumping Plant, located several miles to the east of Grapevine. This plant provides the largest water lift in the world. Fourteen, four-stage pumps of 320 cfs & 80,000 hp each (total installed capacity of 4,480 cfs and 1,120,000 hp) lift the water 1,926 feet over the hill and into the Antelope Valley. From there the aqueduct bifurcates into West and East Branches. The East Branch transports up to 2,880 cfs southeast a distance of 125 miles via open-channel canal, pipeline and tunnel to it’s terminus Paris Dam. Along the way are three power plants, one pumping plant and two large reservoirs. The West Branch transports up to 3,200 cfs a total of 31 miles via open-channel