The Earthen Berm East of Amboy

Hey Matt:
Can you find out why an earthen berm was constructed along the north side of the National Trails Highway/Route 66 for many miles east of Amboy, CA? Does it still serve any purpose? Was it to protect the roadway from drifting sand? If so, why only there? The terrain seems the same for many more miles in either direction east and west of the berm. I’ve been able to find references to it, but no explanation.
— Old Codger, La Mesa

When it rains in Amboy, or anywhere out in the desert, the sky has the annoying habit of dropping two inches of water in ten minutes. This, in conjunction with damage from traffic, destroys roadway shoulders. Berms, like the ones out in Amboy and other places in rural California, are in place so that graders can come and “shoulder” the road with the earth from the berms.

The section of highway you’re thinking of was constructed mostly in the 1950s, and it was maintained by the state (which built the original berms) when Route 66 was the “Mother Road” and the way that everyone from Dust Bowl Joads to hopeful young actresses got to the promised land of L.A. Nowadays, I-40 is the main corridor and the county maintains the sections of old Route 66 that still exist and pass through ghost towns, broken dreams, and half-forgotten memories. Traffic is less than it once was, but the roads still need maintenance and the berms still serve their purpose.