As it does every so often, the Hope Ranch “volcano” rumbled to life this weekend.
“The temperamental geological phenomenon known as the Hope Ranch Volcano awoke Saturday morning, starting a small but smoky vegetation fire on the hillside approx. 1 mile west of Arroyo Burro Beach,” said County Fire spokesperson Mike Eliason in a tweet.
The small blaze didn’t threaten any structures and was quickly put down, Eliason said.
The “volcano” is in fact a solfatara, or “fire well” — naturally occurring fissures that give off sulfurous gases and steam, which can get hot enough to ignite nearby brush. The last solfatara fire in the area occurred in December 2020, and before that in 2019 and 2017.
Observations date as far back as the 18th century, when then-California governor Pedro Fages described “geysers that exude dense smoke” below present-day Hope Ranch. Another solfatara was discovered in 1835 at Rincon, which by the 1880s was sending out flames 10 feet high and flinging rocks into the air before eventually going dormant.