Amboy Crater – San Bernardino County, California - Atlas Obscura
Free iron-on Atlas Obscura badge when you preorder our new kids’ book. Shop now.

San Bernardino County, California

Amboy Crater

This dormant volcanic crater has been converted from a roiling pit of magma to a pleasant hiking spot. 

Rising up out of the California scenery along historic Route 66, the Amboy Crater provides a large and picturesque reminder of a more violent geological time. 

The black rock caldera of the crater was formed around 79,000 years ago when a lake of lava roiled about inside the crater. and created the lonely landmark. With the establishment of the Route 66 highway nearby, the formerly isolated volcano (now long extinct) began attracting droves of tourists looking to set foot in the crater and know that they had walked inside a real volcano. Amboy Crater was the only dead volcano along the entire route and as such, garnered near constant attention.

As other highways were finished and Route 66’s singular popularity faded, the Amboy Crater once again became just a lonely mountain. However, in more recent times, as roadtrippers and families are once again starting to gravitate back to the iconic road,  the Amboy Crater is once again receiving regular visitors. This crater might be cool, but it is once again becoming hot.