Nature is terrifying, haunting, beautiful, inspirational and unpredictable by turns.

As humans, we need that special connection to nature to feel whole; we need to stay some way in touch with our more primitive side even (and perhaps especially) as our world becomes ever-more centered around technology.

Some know this more than others. Heck, some people dedicate their entire lives to the outdoors, to better understanding the delicate balance we share with nature, and the harmony in all things, well… natural.

Casey Anderson, 49, is a wildlife photographer based in the US who tracks animals throughout the American West.

He has a great respect for the creatures we share this planet with, and endeavors to both help and better understand them through his work.

Ten years ago, he left a camera inside a cave that he knew was being used as a bear den, wanting to capture what goes on in such an environment when humans aren’t around. In the absence of any sort of manmade interference, what sort of things might occur in such a spot over a prolonged period?

Well, a video posted to Casey’s Instagram page earlier this year shows him returning to collect the camera after leaving it in place a decade ago. As you might imagine, there was a lot of footage to trawl through.

The process itself is known as a ‘camera trap’, and is the ideal way for photographers to capture wildlife in its rawest, realist form in the wild. As mentioned above, it’s difficult, if not not impossible, to replicate an animal’s natural behavior when humans are around.

Fortunately for Casey, his hunch that the bear den in question was a perfect spot to set up a vigil proved to be true.

“Not only had bears returned, but so had mountain lions, coyotes, and a surprising variety of smaller animals,” he told Newsweek. “One mountain lion in particular kept returning again and again, almost obsessively.”

He added: “This kind of discovery is what drives me. I’ve spent my life locating wild places and setting up cameras to quietly observe what unfolds when no one is around.”

The footage included a mountain lion, coyotes, and grizzly bears who frequented the cave.

Casey also expressed his shock at the batteries having lasted for so long, while revealing that the camera had not been active for the entire ten years as a “Bear knocked it over.”