San Bernardino County history: Mojave National Preserve

"San Bernardino County Update", yellow arrowhead and "SBCounty.gov

A rock surface is shown with a dinosaur footprint fossil embedded in the stone. — *California’s oldest dinosaur footprints are in San Bernardino County.*

The Mojave National Preserve is located between Interstate 15 and Interstate 40 in San Bernardino County. Covering 1.6 million acres, it is the third largest park of the National Park System in the contiguous United States. The preserve contains many natural features, including the Kelso Dunes, the Marl Mountains, Cima Dome and Cinder Cone Lava Beds.

The land within the preserve holds a long and layered history. Human activity in the region dates back thousands of years. The Chemehuevi people lived in the mountains, canyons and along the Colorado River shoreline. In the late 1800s, miners began to explore the desert for gold, copper, silver and iron.

One of the most significant mining operations was run by Kaiser Steel at the Vulcan Mine. The mine is located in the eastern Mojave Desert near Kelso, within what is now the Mojave National Preserve. During the 1940s, Kaiser Steel extracted more than two million tons of iron ore from the Vulcan Mine, which was used to help build Liberty ships during World War II.

The preserve is also known for its ancient natural history. In 1950, scientists discovered fossilized dinosaur footprints in the Mescal Range near Mountain Pass in eastern San Bernardino County. This area is part of the Mojave region and lies within what is now protected land. The tracks were identified as the footprints of small bipedal dinosaurs called coelurosaurs. Each footprint is about the size of a human hand. They were preserved in Aztec Sandstone, which dates back to the Early and Middle Jurassic periods about 173 to 170 million years old [MC1] [JA2] .

According to the San Bernardino County Museum, they are the only dinosaur footprint fossils ever discovered in Southern California and the oldest in the entire state. Their discovery shows that the eastern Mojave region once had an environment of coastal sand dunes with fog and mist, much like today’s Atacama Desert in South America.

On Oct. 31, 1994, Congress passed the California Desert Protection Act, which officially established the Mojave National Preserve. Today, the Kelso Depot, which once provided food, recreation and lodging for Union Pacific Railroad employees, now serves as the visitor center for the Mojave National Preserve. 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 – March 5, 2026