San Bernardino County history: Amboy Crater – Welcome to San Bernardino County

A picture of Amboy Crater in the Mojave Desert featuring a volcanic cone surrounded by lava fields. — *Amboy Crater in the Mojave Desert.*

Amboy Crater stands as a reminder of this region’s geological history. More than 500 volcanic vents have been identified in California, with at least 76 having erupted during the last 10,000 years. Among them is Amboy Crater, a 79,000-year-old cinder cone located between Barstow and Needles.

Cinder cones, the simplest type of volcano, are formed from lava particles ejected from a single vent. Amboy Crater is a collection of four nested cones, which indicate at least four eruptions from the same volcanic center.

Its last eruption is estimated to have occurred over 10,000 years ago. Amboy Crater spans about 1,500 feet in diameter and rises approximately 250 feet. It is situated in one of the youngest volcanic fields in the United States. The area around Amboy Crater was first settled in 1858, but the nearby town of Amboy was not established until 1883. The town of Amboy was named by Lewis Kingman, an engineer for the Atlantic and Pacific Railroad.

The Amboy area is known for its mining history. It includes 22,473 nearby mines, many abandoned, that once produced gold, iron and salt from Bristol Dry Lake. Amboy is one of only a few locations worldwide that contain boltwoodite, a rare uranium mineral.

In 1959, the volcano did “erupt” Hollywood style. The crater was used as a location for the movie “Journey to the Center of the Earth.” The movie crew set various materials ablaze inside the cone to give the effect of an eruption.

In May 1973, Amboy was officially designated as a National Natural Landmark, which recognizes its geological significance.

The information in this historical feature was originally part of a video series produced by the Assessor-Recorder-County Clerk’s office.

Additional County Update News – August 28, 2025