Skip to content 
“I’ll be honest, my first thought was that we’d finally have some closure for the family,” Tessmer said. “Maybe we’d see what happened in those final moments, a medical emergency, equipment failure, something that would explain the accident. I never expected what we actually found.”
The camera’s memory card contained 32 GB of footage. All of it recorded on September 15th, 2022, the day Marcus disappeared. The 1st several hours showed exactly what investigators expected: beautiful shots of the Buffalo River from a kayaker’s perspective, with Marcus occasionally speaking to the camera to describe the geology or wildlife he was documenting. His voice on the early footage was relaxed, professional, the tone of someone doing work he loved in a place that made him happy. He pointed out a great blue heron fishing in the shallows near Steel Creek, explained the difference between limestone and sandstone formations along the bluffs, and made technical notes about lighting and camera angles for his book project.
“Hour 3, mile marker 7,” Marcus’s voice said on the recording, his kayak drifting in calm water below a towering bluff. “Getting some great shots of the overhang formations here. The book editor was right about needing the water-level perspective. You can’t see these undercuts from above.”
Around hour 4, the footage showed Marcus pulling his kayak up on a gravel bar near what appeared to be a large cave opening at water level. This was familiar territory. Hemmed-in Hollow and its network of limestone caves were well-known features of the Buffalo River.
What was not familiar was the particular cave Marcus had found, hidden behind a curtain of vegetation and accessible only from the water during certain river conditions.
“Okay, this is interesting,” Marcus said to the camera, his voice taking on the excited tone of someone who had discovered something unexpected. “I’ve got what looks like a significant cave opening here, maybe 15 ft high, directly accessible from the river. I don’t think this is on any of the standard cave maps for this area.”
The next portion of footage showed Marcus securing his kayak to a fallen log and gathering his photography equipment. He checked his headlamp, verified that his backup batteries were in his pack, and took a GPS reading on his phone. Everything about his preparation suggested someone who understood cave-safety basics and was not taking unnecessary risks.
“Just going to do a quick reconnaissance,” Marcus said to the camera. “Maybe get some shots of the entrance chamber, see if there’s anything worth coming back for with proper caving gear. I’ve got about 3 hours of daylight left, so plenty of time to explore a bit and still make it to the takeout by dark.”
He clipped the GoPro to his helmet and entered the cave.
For the next 3 hours, the footage revealed a wonderland of limestone formations, flowstone cascades, delicate draperies, and columns that had been growing for thousands of years. Marcus moved carefully through the cave, stopping frequently to photograph particularly striking features. His commentary was knowledgeable and enthusiastic, suggesting someone who had spent considerable time in similar underground environments.
“This is absolutely incredible,” Marcus said as his headlamp illuminated a chamber filled with pristine white formations. “I don’t think this cave sees much traffic at all. Everything is completely undamaged. No graffiti, no broken formations. This could be really significant from a conservation perspective.”
But by hour 7, the excitement in Marcus’s voice had been replaced by concern.
The cave system was more complex than he had initially realized, with multiple passages branching in different directions. What had seemed like a simple reconnaissance trip into a single chamber was becoming something much more complicated.
“Okay, I think I may have taken a wrong turn somewhere,” Marcus said, his headlamp beam sweeping across an unfamiliar passage. “This doesn’t look like the route I came in on. The formations are different, and the ceiling height is wrong.”
The next hour of footage documented Marcus’s growing realization that he was lost in a cave system far more extensive than anything he had anticipated. His initial calm began giving way to controlled concern as he tried passage after passage, looking for the familiar landmarks that would guide him back to the entrance.
“My backup batteries are getting low,” Marcus reported around hour 8. “I need to find the main passage soon or this is going to become a much bigger problem than I planned for.”
By hour 9, with his primary headlamp batteries failing and his backup light providing only dim illumination, Marcus’s situation had become genuinely dangerous. The cave system stretched in multiple directions, with passages that seemed to circle back on themselves and side tunnels that led to dead ends or dangerous drops.
“If anyone finds this footage,” Marcus said, his voice tight with controlled fear, “I’m in a cave system near Hemmed-in Hollow on the Buffalo River. Large entrance at water level, maybe a/4 mile downstream from the main hollow opening. I came in around noon on September 15th, 2022, and I can’t find my way back out.”
He began leaving messages for his family, telling his sister how much he loved her, asking her to take care of their aging father, expressing regret for the worry his disappearance would cause. These portions of the recording were almost unbearable to listen to, investigators said later.
“Here was a man who understood his situation clearly, who knew he might not survive, trying to leave something meaningful for the people he would never see again.”
But around hour 11, something changed.
Marcus stopped talking.