The Plank Road
The Plank Road constructed across the Imperial Sand Dunes in 1915 was rebuilt by the California Highway Department a year later.
The narrow, one-track road with turnouts for opposing traffic to pass was difficult to keep clear of drifting sand dunes. It was nonetheless the main road between Yuma and San Diego until 1926 when a wider, paved road was built across the dunes on a high berm for transcontinental U.S. 80. It took a long time for the Plank Road to deteriorate in the arid climate of the Imperial Valley. 
A 1,500-foot segment of the old wooden road still exists, 
hobbled together in the 1970s from scattered remnant pieces as an historic landmark located on Grays Wells Road just south of Interstate 8.