One of California's riskiest volcanoes has for decades been undergoing geological changes and seismic activity, which are sometimes a precursor to an eruption, but -- thankfully -- no supervolcanic eruptions are expected. That's according to Caltech researchers who have been studying the Long Valley Caldera, which includes the Mammoth Lakes area in Mono County. The caldera was classified in 2018 by the U.S. Geological Survey as one of three volcanoes in the state -- along with 15 elsewhere in the U.S. -- considered a "very high threat," the highest-risk category defined by the agency. The two other volcanoes in California with that classification are Mt. Shasta in Siskiyou County and the Lassen Volcanic Center, which includes Lassen Peak in Shasta County.

Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. Deputies are asking for the public's help in the search for missing teenage Utah farmer Dylan Rounds, who vanished from his Lucin property late last month and was last seen in public three weeks ago. "If you have knowledge regarding the circumstances surrounding the disappearance of Dylan Rounds, or his current location, call the Box Edler County Sheriff's Office," Chief Deputy Cade Palmer said in a statement. After friends and family grew concerned about his whereabouts, a search team found his boots in the dirt roughly 100 yards from his truck – in the opposite direction of his camper, according to his mother Candice Cooley. Her son has farming in his blood, she said, and has been entirely focused on working his land, foregoing other activities young men his age might be doing instead, including video games, drugs and social media.

The Elko County Sheriff's Office says it has acquired a new drone which it plans to use during special events, search and rescue missions, missing persons, crime scenes and traffic collisions.