Recently in Tuolumne County, adventurer friends Max Wheeler and Donald wanson uncovered something unexpected, which might be par for the course when you spend your time searching for and exploring underground caves and mines. 

Uncovering 200-feet-deep mine shafts, a working ore cart and tracks, and a miner’s cabin made of scrap and salvaged sheet metal, the two had a pretty good day discovering the hidden secrets of a Tuolumne County hillside. In a video uploaded to Wheeler’s YouTube channel a day later, titled “HUGE Awesome Underground Discoveries totally unexpected,” Wheeler also revealed what he called a “mind-blowing” discovery—a fairly intact brick building deep beneath the town of Sonora, which Wheeler said is “bigger than imagined” and “goes way under the street.”


A still working ore cart sits on a track near the end of this cave in Tuolumne County.

While this location is undisclosed, other underground tunnels leading to mines have been discovered beneath the historic part of town, though most have been sealed off for safety. The entrance to one such mine tunnel can be seen in the underground bookstore, Legends Books, Antiques & Soda Fountain.

Access to tunnels and mines that remain open are kept secret amongst the explorers and their close-knit community, for fear of them being overrun and vandalized or damaged by visitors. Many are also found on private property, so finding and gaining access to an underground building that may be over 100 years old is a dream come true for explorers like Wheeler and Swanson. It’s also a reward for their efforts. Wheeler wrote in a social media post, “This is all what comes from intense hikes, walking hillsides, sweat, and asking, searching maps and knocking on doors.”


Adventurers Max Wheeler and Donald Swanson explore caves and old mines together throughout Gold Country.

Swanson told the Enterprise, “Anyone from Sonora knows that there are mining tunnels right beneath Washington Street, but what most people do not know is that below those man-made tunnels is a lot more to be seen. Miles and miles of hidden rocky passages that haven’t been traversed in over 50 years. … Access to these hollowed-out wonders is extremely limited and regulated due to safety concerns.”

Even if granted access, safety is still a huge concern for those exploring underground. Fitness, safety training, and proper gear are essential for survival in these dark and dangerous places. Wheeler has six safety rules he adheres to, which include bringing backups of everything from lights to vehicles, saying you never wanna get broke down somewhere.” He also advises that cave exploration is “not for everyone,” requiring physical dexterity to hike for several miles, climb, crawl and pull oneself through tight spaces, and navigate wet, dark spaces that could potentially contain toxic gasses or even collapse.


The underground expeditions often are difficult and dangerous, but worth it for the explorers when relics of the past are found.

Wheeler keeps his adventure companions to a trusted few—mostly Swanson and occasionally others from the community who are “already familiar with what caving and exploring the underground is like.” This keeps everyone safer and also limits the amount of exposure and potential damage to the caves and mines they explore.

Wheeler and Swanson began exploring together after the two connected through a comment on one of Wheeler’s Youtube videos. Both Wheeler and Swanson operate a YouTube channel and Facebook groups through which they share photos, videos, and details of their Gold Country findings. Wheeler runs the Down To Earth Exploring channel and group, and Swanson runs Gold Country Adventure and Exploration

Swanson says the inspiration for his Facebook group, which now has nearly 14,000 members, is to “share with the world what is hidden in these hills as well as practicing good conduct with these fragile and sometimes dangerous sites.” Wheeler has a similar goal, saying he mostly wants to “let the public know what is out there” and share his respect for these natural and man-made marvels. Wheeler adds that they “have a very high-level interest in the preservation” of these spaces, which is one reason why they don’t disclose the exact location of the mines and caves they find and discourage others from doing so.

“These mountains hide a lot of history,” says Swanson, and he finds joy in literally bringing that history to light, through the lens of his video camera or cell phone.


Numerous natural and man-made cave systems can be found throughout Gold Country, making it the perfect home for adventurers like Swanson and Wheeler. 

“Documenting and photographing these historical treasures is vital because the toll of time is limited on certain artifacts,” Swanson explained.

Swanson stated that he has been in 2,157 abandoned mines and cave systems so far, despite only being at it for about two years. He enjoys seeking out the more remote and hard-to-reach areas, saying they are typically the most “mysterious and historically undisturbed” locations. Calaveras and neighboring Tuolumne County have plenty of these spots, which could be why they are among Swanson’s favorite places to explore in the Gold Country.

“Calaveras and Tuolumne Counties are both among my favorites. … If you want natural history, then you can have it. If you want mining history, then you can have that as well. The options are nearly limitless with adventure,” said Swanson.

Wheeler doesn’t have a favorite area but says he enjoys anything that amazes him, like the building they discovered two levels below Washington Street in Sonora last week. When out at a new location, the duo hopes to discover relics of the past, like mining carts and tracks, abandoned equipment and structural elements, and natural formations on cave walls and ceilings. 

“We are in this for the history, the mystery, what was cut by man, and formed by nature,” reports Wheeler.

24-underground9 (2).jpg

Swanson points to pickaxe marks on the wall of a Tuolumne County cave.

Wheeler says those interested in underground exploration ought to “always be respectful and remember it has been there much much longer than we have ever have. ... Take pictures, leave footprints, make memories.”

To learn more about Swanson and Wheeler’s discoveries, follow them on Facebook and YouTube. Those interested in visiting caves should consider one of several guided tours in the area, such as Mercer Caverns, Moaning Caverns Adventure Park, or California Cavern—much safer and more accessible options that don’t require the special equipment, knowledge, or training that Swanson and Wheeler bring into the caves they visit. 


Marie-Elena studied creative writing, art, and photography at University of Nebraska at Omaha, graduating with a BA in Studio Art -Visual Media. She moved to California from Nebraska in 2019 and is happy to call Calaveras County her home.

Comment Policy

Calaveras Enterprise does not actively monitor comments. However, staff does read through to assess reader interest. When abusive or foul language is used or directed toward other commenters, those comments will be deleted. If a commenter continues to use such language, that person will be blocked from commenting. We wish to foster a community of communication and a sharing of ideas, and we truly value readers' input.