Teachers Spot

The San Diego Automotive Museum's Educational Programming offers the children of San Diego an opportunity for a number of educational experiences. The automobile represents a wide range of subject matter, from Social Studies (including local-national history), to science and physics along with technology and art.

The impact of the automobile on American society is large and has been long lasting. At the Museum, a child can begin to understand how important the industry is and how it has helped to shape our national identity.

The museum also participate in San Diego Unified School District's award-wining Balboa Park program.  5th grade students spend an entire week in the park visiting many of the cultural institutions.

  • Teacher’s Spot

 The museum offers curriculum for specialty exhibits throughout the year.  One of our most historically significant displays is the Old Plank Road that ran from Yuma, Arizona to Holtville, California.  The following lesson is an excellent pre-visit experience for students grades 4-6.

 Curriculum Guide

The Old Plank Road

Edition 2   May 2011

 This Informal Curriculum Experience (ICE) is geared for high school students grades 10-12.  The California Standards-based areas covered and suggested teaching elements are:

History (history of transportation and how it built cities, communities, and culture)

Geography (the history and topography of the California desert)

Critical Thinking (how one might navigate a plank road today)

English/Writing & Composition (imaginary diary of a plank road traveler)

Math (calculating time and expense to drive the Old Plank Road in 1922)

Goals:  Students will learn about plank roads as early highway systems in the United States.  Of particular interest is the Old Plank Road that ran from Yuma, Arizona to Holtville, California.  The students will study the history of the development of the road that eventually became Interstate 8 and its importance to the Imperial Valley.


Students will be able to identify Yuma, Arizona and Holtville, California on a map.

Students will be able to name the key developers of the Old Plank Road.

Students will be able to list at least three challenges the Old Plank Road presented to designers and those who traveled the road.

Students will be able to identify the progressions in the Old Plank Road until it became today’s Interstate 8.

Students will correctly identify the location and discuss the importance of Gray’s Well to the development of the roadway.

Students will correctly list three reasons for building the Old Plank Road and the impact that had on the development of San Diego as a West Coast city of importance.

Writing Assignment

Most information you need to give your students is included in the pre-visit materials.  It is also covered extensively in the interpretive exhibit on the museum floor.  A writing assignment is a good way to tie all the curricular elements together.  After watching the oral histories on the exhibit video, your students will have a better idea of what it was like for early users of the road.

Have your students prepare a “diary” entry of an imaginary trip on the Old Plank Road.  Encourage them to use everything they have learned about the challenges along the way, Gray’s Well as a stopping point, sand storms, etc.  What is their reason for traveling the road?  Are there any surprises?  How has San Diego changed since they made the trip?


Ever since the dawn of transportation, roads have been a necessary thing.  Roads make it easy to move people, machines, and good from place to another without the struggle of navigating through forests, across the vast prairies, or….in San Diego’s case….across the desert. 

Making roads from wooden planks was a method that served people well over the years.  Wood was easy to get in certain parts of the country, so making plank roads seemed only logical.

Plank road through the forests of Oregon and Washington.  Note, this pre-dates the automobile.

The dampness and rugged weather made these roads useless in a matter of years.  Left untreated, the wood rotted.  Replacement was time-consuming.  Keeping the roadway clear of weeds was also a challenge. 

Plank roads were also used in southern states with more success because of drier weather.

 Hauling a large load of crops with a mule-drawn wagon over a plank road.

The dawn of the automobile made plank roads even more necessary.  More plank roads then ever were built once the automobile became popular.  Their design was not the best.

 Early automobile driving down plank road that was literally four planks laid parallel to the wheels.

California became a prime destination after the Gold Rush years.  The state boomed in numbers of people an as national importance.  People wanted to go to California, but crossing the sand dunes from Imperial County to Yuma, Arizona proved to be an almost impossible task.  The solution was building a plank road. 

The era of automobile transportation and the growing rivalry of two Southern California cities, San Diego and Los Angeles were the reasons for building the road. Just as railroad towns owed their financial well-being to rail commerce, communities linked by good roads would benefit from the automobile. Civic and business leaders quickly perceived the benefits of bringing routes and roads to their communities. Having lost a bid to become a terminus for the Transcontinental Railroad, San Diego was determined to beat Los Angeles to become the hub of the Southern California road network.

Chief among the promoters for San Diego was businessman and road builder "Colonel" Ed Fletcher. Fletcher sponsored a road race to demonstrate the best route between Southern California and Phoenix, Arizona.  The Los Angeles newspaper, the Examiner, issued a personal challenge to Fletcher, and a race was set for October 1912. With a 24-hour head start, an Examiner reporter would travel from Los Angeles to Phoenix, and Fletcher would proceed from San Diego, each attempting to demonstrate the feasibility of his chosen route. Fletcher chose a route through the Imperial Sand Hills, and with a team of six horses to pull his automobile through the sand, Fletcher won the race in just over 19 hours!

Two developments contributed to the success of Fletcher's plan. First, Imperial County Supervisor Ed Boyd joined Fletcher in advocating the Sand Hills route as a direct east-to-west course between Yuma, Arizona, and San Diego. Second, the federal government and the States of California and Arizona approved construction of a bridge across the Colorado River at Yuma. In addition, San Diego announced plans to hold an exhibition celebrating the opening of the Panama Canal in 1915, an event designed to lure thousands of visitors, many traveling by automobile. Could a reliable way be found to cross the shifting sand dunes?

With local newspapers supporting the plan, Fletcher raised the money to pay for 13,000 planks plus the freight to ship them from San Diego to Holtville, California.  Boyd and his constituents persuaded the Imperial County Board of Supervisors to appropriate $8,600 toward construction expenses. L.F. (Newt) Gray, a local man chosen to supervise road building, sank a well at the western edge of the Sand Hills and found water. Gray's Well, as the spot became known, served as the work camp.

Amid great fanfare, the first planks were laid on February 14, 1915. For the next two months, a combination of volunteers and paid workers hauled lumber and laid down two parallel plank tracks, each 25" wide, spiked to wooden crosspieces underneath. The wheel path floated across 6 1/2 miles of shifting sand east of Gray's Well. Work ended on April 4, 1915. A week later, an excursion of 25 cars loaded with over 100 riders traveled the road and declared it a success.

But what was it really like?  Was it glamorous?  Was it full of adventure?  Was it dangerous?  Was it boring?

Stuck in the sand.  A common sight along the early road.  Drivers tended to slip off the tracks.  Modifications made the road more stable.  See photo below.

Car navigating the road as sand encroaches, making drifts that were impassable at times.  Clearing sand was a daily job for the maintenance crew.

Picture yourself back in 1918 trying to cross the burning desert of Imperial County. You reach the treacherous Imperial County sand dunes and face the challenge of a seamless ocean of sand. With relief and anxiety, you begin to ascend the first dune on the Plank Road. The heat, swirling sand, and jarring ride across the rough planks makes you nauseous, but you are grateful since this new route offers safety and cuts many hours off the adventurous trip across the desert. 

The Old Plank Road really only covered a small section of the road from Yuma to San Diego.  Once past the dunes, the road was fairly navigable.

Traffic, however, quickly took a heavy toll on the planks. Battered by the passing cars of tourists and farmers, the road was splintered further by maintenance crews who uncovered the wooden road with mule drawn scrapers to clear it of drifting sand. Still, Fletcher and Boyd had proved that a road was feasible, and motorists had demonstrated the necessity for a good road. In June 1915, the California State Highway Commission assumed responsibility for the Plank Road as part of the road system linking Southern California with Arizona.

With more funds, manpower, and equipment than the pioneer road builders, the Highway Commission built a new Plank Road in 1916. Engineers abandoned the double-track plan and designed a roadway of wooden cross ties laid to a width of 8 feet with double-width turnouts every-1,000 feet. Sections 12 feet long were preassembled at a fabricating plant set up at the railroad town of Ogilby, California. Completed units, which weighed 1,500 pounds each, were transferred onto wagons by means of a derrick specially designed for the task. Out in the dunes, workers prepared the roadbed by leveling the sand with scrapers. Sections of the Plank Road were then lowered into place using a crane.  It was an engineering accomplishment!

Plank Road upkeep proved difficult, and a permanent maintenance force was stationed near Gray's Well. From 1916 to 1926, crews of workmen struggled incessantly against nature to keep the road passable. Hard winds blew drifting sand across the road an average of two or three days a week, rendering the road nearly impassable about one-third of the time. The crew routinely worked the road with Fresno scrapers hitched to a team of draft animals, and travelers huddled in their vehicles while the sand swirled around them.

Crossing the Plank Road was both an adventure and a trial. Pulling off the road onto the turnouts so that others might pass tried the patience of motorists. Traffic jams in the midst of desert vastness were not uncommon. On one occasion, a caravan of 20 cars encountered a lone traveler going in the opposite direction.  The driver was either frightened to back up or just plain stubborn.  Finally, the driving party took matters in hand. The men lifted the car and set it on the sand, while the women proceeded to advance the caravan. When they were past, the car was lifted back up on the road, and all continued on their way. Turnouts along the Plank Road were marked with old tires mounted on high posts to make them visible from afar.

Despite the discomfort and outright danger of crossing the Plank Road, former travelers still recall with amusement the feeling of high adventure that was part of the Plank Road experience. While the road opened up a valuable trade route for Imperial Valley farmers and townsfolk, riding across it also became a favorite winter recreational activity.

High school chums, church youth groups, and families often jounced across the road to Gray's Well with a picnic lunch or a camp stove for a steak-fry. In fact, desert parties were so popular that Gray's Well usually resembled a campground during the winter months. Newt Gray obliged travelers and desert party groups alike by stocking a small, tin roofed store with emergency provisions and cold drinks. During Prohibition, more potent liquids reportedly were available to slake one's thirst.

Gray’s Well…..the first “convenience store” of the Imperial Desert!

The days of the Plank Road were numbered. The twin headaches of maintenance and traffic flow required a better solution. Non-technical suggestions ranged from digging a tunnel under the sand to elevating a structure above it. The State Highway Commission received unsolicited advice, while highway engineers studied the problem of attaching a traversable surface to an unstable roadbed. In 1924 the Commission tested a new, improved Plank Road which would permit two-way traffic to cross the dunes.

From 1923 to 1925, engineers monitored the movement of sand dunes adjacent to the Plank Road and tested various surfaces. After concluding that hills of sand over 100 feet high moved very slowly and only the lower dunes moved rapidly, it was determined that a permanent pavement; road was indeed possible providing the grade was sufficiently raised.

With an engineering solution at hand, the Highway Commission decided on an asphalt-like concrete surface constructed on top of a built-up sand embankment. The new road, 20 feet wide, officially opened on August 12, 1926. Praise for the highway was mixed with a certain nostalgia for the primitive wooden contraption it replaced. After all, the Plank Road had added a bit of spice to life in the Imperial Valley.  The new road was called Highway 80.  That changed over time and is now called Interstate 8.

Despite pleas from local residents for preservation, the Plank Road began to disappear: a section to the Ford Motor Company for display purposes, another section to the Automobile Club of Southern California for installation at its Los Angeles headquarters, and another section ripped up to make way for the All-American Canal, and so on. Countless cross ties literally went up in smoke as firewood for campers.  General Patton is reputed to have burned countless pieces of the road while out in the desert on military maneuvers.

Now, only fragments of the Plank Road remain, protected under the jurisdiction of the Bureau of Land Management, and the route is designated as an Area of Critical Environmental Concern. In recognition of the Plank Road's stature as an important historic example of transportation technology, the State of California designated its ruins as a California Historical Landmark. Portions of the road also are considered eligible for inclusion in the National Register of Historic Places.

Remnants of the Plank Road may be seen at the west end of Gray’s Well Road, the frontage road south of Interstate 8. A Plank Road monument and interpretive display lie approximately three miles west of the Sand Hills interchange. This portion was preserved as a result of efforts by the Bureau of Land Management, the Imperial Valley Pioneer Historical Society, the California Off-Road Vehicle Association, and Air Force personnel. These groups worked together in the early 1970’s to assemble a 1,500 foot section from various locations in the dunes.

The Plank Road memorializes the determination and vision of those who forged the first automobile highway across the Sand Hills. Preservation of the old wooden road is the responsibility of all who use the desert. Time and circumstances have not been kind to this historic landmark. We invite you to help us ensure that the Plank Road reaches its centennial.

When you visit the San Diego Automotive Museum, you will see a diorama of a Model T crossing the desert on the Old Plank Road.  The car is sitting on real planks that were donated to the museum by the Hazard family back in the early 1990’s.  Oral histories of people who remember the road are also playing as part of the exhibit.  There are many pictures of how people navigated the road, including some ingenious ways people adapted their cars.

The Old Plank Road was built, in part, to allow people to come to San Diego to participate in the Panama-California Exposition of 1915.  That exposition was built in Balboa Park.  The San Diego Automotive Museum is currently housed in Balboa Park in a building that was constructed for the California Pacific Expo of 1935.  How fitting that relics from the Old Plank Road be housed in a Balboa Park building dedicated to the preservation of automotive history.