Welcome to Sonora, California: a beautiful old mountain town that was once the center of the California Gold Rush, and where every day, like clockwork, residents are startled by a loud "boom" that occurs between the hours of 11 a.m. and 2 p.m.
As ABC News reports, the loud booms -- lovingly given the nickname "Mother Lode Mystery Booms" -- have puzzled residents of Sonora for years, and everything from mining to earthquakes to aliens, and everything in between, has been offered up as a cause.
In a July 2015 WTEN (Albany) report, Sonora resident Kira Keegan described how the booms shake her very soul.
"You just hear these booms, they're very low, you know, you almost feel them."
As it turns out, there may be a rather mundane explanation for those booms. About a hundred miles away from Sonora, across the Sierra Nevada mountains, is the Hawthorne, Nevada Army Depot. There, a private company disposes of old munitions -- bombs, grenades, and what have you.
And wouldn't you know it, the detonations take place each day between 11 a.m. and 2 p.m.
Local geologist Ken White has even gone to Hawthorne and recorded the detonations himself.
"They go through old munitions bombs, grenades, then they destroy them."
So, problem solved, right? Not so fast: There are a couple of problems with White's conclusion, not the least of which is the fact that Hawthorne is about 175 miles from Sonora, and the two towns are separated by a mountain range.
Even Ken Thomas, who actually works at the Hawthorne Army Depot, isn't buying it.
"It doesn't feel right that what we're doing here would be heard 200 miles away when there's a mountain range in between us. My office is 27 miles from where they detonate the old munitions, I only hear it here maybe one time a month, and just barely and it's like 'Was that a boom?'"
White admits that it seems a little weird that people living and working close to the detonations would barely notice them, while people living 200 miles away would notice them. But he thinks it has something to do with the atmosphere above the detonation site absorbing energy from the blasts and sending it back to Sonora.
"I can't explain all the physics involved, but the atmosphere is bouncing in response to the energy and it's reflecting and bouncing (the sound) back down. The really odd part is people fairly close to the source of the energy, the explosions, aren't hearing it. The sound goes over them."
In fact, sounds can travel over long distances, as evidenced by the August 27, 1883 eruption of Krakatoa, an Indian Ocean volcano. So loud was the sound, according to Nautilus, that sound waves from the eruption circled the earth four times, and observers as far as 3,000 miles away described hearing it. And the captain of the British ship Norham Castle, which was a mere 40 miles away, described the gruesome injuries suffered by his crew as a result of the sound alone.
"So violent are the explosions that the ear-drums of over half my crew have been shattered. My last thoughts are with my dear wife. I am convinced that the Day of Judgement has come."
Sonora, California is not the only town plagued by mysterious noises. Perhaps the most famous mystery noise to plague a small town is the infamous Taos Hum. Since the early 1990's, according to Live Science, at least some residents of the town of Taos, New Mexico, claim to hear an unrelenting hum with no identifiable source.
What do you think is causing the "Mother Lode Mystery Booms" in Sonora, California?