This is obsidian butte, one of five lava domes that comprise the Salton Buttes Volcano on the shore of California's largest lake, which is the Salton Sea located in the Sonoran Desert, in Southern California.
Southern California has an active volcano
As a resident of Southern California, I was surprised when I found out that on the southern shore of the Salton Sea, the largest lake in California, there is an active volcano. The volcano is called the Salton Buttes, and consists of a series of five small lava domes.
The lake itself first came into existence accidentally over a century ago when irrigation canals badly overflowed. The volcano last erupted sometimes between 2,000 and 3,000 years ago, according to a study done in 2012. That is a short time in geology, and the volcano remains a threat for an eruption. USGS rates the potential for another eruption as “high.”
Although there is debate amongst geologists about the definition of an “active” volcano, most often it is defined as any volcano that has erupted in the past 10,000 years and likely to erupt again.
The volcano has a geothermal power plant nearby, and volcanic heat is utilized to power over 300,000 homes.
Directions - how to get to the Salton Buttes Volcano
California State Route 111 runs through the Coachella Valley and the Palm Springs area, and past the east side of the Salton Sea. Both north and south of the lake, it intersects and diverges from California State Route 86.
If you're on Highway 111 near the lake, there are roads that run from this highway westward, right up close to the shore of the lake. The one that takes you over toward the lava domes is called W. Sinclair Rd.
After 4.5 miles heading west on W Sinclair Rd, turn right on Garst Rd, and follow it for 1.5 miles. Then turn left on Red Hill Rd, and in a minute or so, you're there.
There are other volcanoes in California's Mojave Desert
This is Ubehebe Crater in Death Valley. It last erupted about 800 years ago and is considered active and a threat for future eruptions. There are several volcanic craters in the area, and this is the largest one. It's possible to hike to the bottom and then back out. It's difficult but fun - I've done it.
The Coachella Valley and Salton Sea are part of the Sonoran Desert, which extends to the east and south into Arizona and northern Mexico. This is often referred to by Californians as the “lower desert.” The location of the lava domes and the shore of the Salton Sea is below sea level one of only three places in the USA that has land below sea level - the others being Death Valley and New Orleans, Louisiana.
To the north at higher elevation is the Mojave Desert, often called the “upper desert” or the “high desert.” In California’s Mojave Desert there are three more potentially active volcanoes.