On October 12, 2006, the sun set behind the granite peaks of the Sierra Nevada, casting long shadows across the wilderness. What was meant to be a three-day father-and-son camping trip became one of California’s most enduring missing persons cases.
Marcus Hoffman, 42, and his 14-year-old son, Dylan, left their home that morning with plans to hike to Thousand Island Lake. They never returned.
Marcus was not an inexperienced hiker. He had worked as a park ranger for over 15 years and had been exploring the Sierra Nevada since college. Colleagues described him as someone who knew every trail, shelter, and river crossing in the region. Dylan had grown up alongside him in the backcountry. An Eagle Scout candidate and strong student, he could read topographic maps, purify water, and build fires in difficult conditions.
They planned to spend 3 days hiking and camping in one of the most remote sections of the range. There would be no cell service. They expected to return Sunday evening by 7 p.m., in time for Dylan’s school the following morning.
That morning, Marcus loaded their blue Ford Explorer with cold-weather sleeping bags rated to minus 20 degrees, a water filtration system, emergency rations, and gear capable of sustaining them for a week if necessary. Linda Hoffman watched from the kitchen window as they prepared to leave. She had seen them depart for many trips before, but later said something felt different.
They stopped for gas in Mammoth Lakes around 11 a.m., where an attendant recalled Marcus purchasing extra water and trail mix while Dylan studied their maps. Park records show they signed the trail register at the Rush Creek trailhead at 12:47 p.m. Marcus wrote: “M. Hoffman + son, 3 days, Thousand Island Lake Area.”
It was the last confirmed sighting.
When Sunday evening passed without their return, Linda initially assumed the trip had run long. By 9 p.m., concern began to build. Marcus was known for punctuality and reliability. By midnight, she contacted the Mono County Sheriff’s Department.
At dawn Monday morning, search and rescue teams assembled at the Rush Creek trailhead. The Ford Explorer sat untouched. The keys were still in the ignition. Windows were cracked slightly. Nothing appeared disturbed. Dylan’s homework folder lay in the back seat, a math test scheduled for Monday morning inside.
Detective James Rodriguez arrived at 7 a.m. The vehicle showed no signs of struggle or foul play. Search dogs picked up their scent along the main trail. For 5 miles, the dogs tracked them steadily past Agnew Lake and through junction points toward Thousand Island Lake.
At mile marker 6.5, the dogs stopped.
They circled and whined, unable to continue. Handler Jim Collins reported that the animals were behaving as if the trail had simply ended.
Search teams expanded outward from that point. Helicopters flew grid patterns overhead, though dense forest canopy limited visibility. Ground crews searched switchbacks, creek crossings, ravines, and potential shelter sites. Mountain rescue teams descended into caves and gorges.
Over 72 hours, more than 200 volunteers combed 75 square miles of wilderness. They found nothing.
The search widened. Backcountry campsites within a 20-mile radius were checked. Abandoned mining claims, remote fishing spots, and unofficial routes used by experienced hikers were examined. News coverage brought additional volunteers and Marcus’s fellow rangers joined the effort.
By day 5, it had become the largest missing persons search in Sierra Nevada history.
Weather remained clear during the initial search, though nighttime temperatures dropped below freezing. By October 18, Sheriff Martinez announced the operation was transitioning from rescue to recovery. On November 5, after early snow made operations dangerous, the active search was suspended.
Linda refused to accept that her husband and son were gone. Through the winter, she organized volunteer efforts and personally hiked as far as she could manage, calling their names into the cold air. Spring brought renewed searches, including avalanche zones and creek beds exposed by snowmelt. Ground-penetrating radar was used in select areas, but the terrain was too vast for comprehensive coverage.
No evidence surfaced.
Years passed. National media featured the case. Tips were investigated: sightings near Lake Tahoe, reports from remote cabins, speculation about wildlife attacks or hidden cave systems. None produced results.
In March 2013, nearly 7 years after their disappearance, Marcus and Dylan Hoffman were legally declared dead. Linda used much of the insurance settlement to fund continued searches and retain a private investigator.
The Sierra Nevada yielded no answers.
In September 2024, 18 years after the disappearance, a breakthrough came from an unrelated source.
At the University of California, Davis, Dr. Sarah Martinez was conducting a wildlife survey tracking a recently documented wolf pack in the Sierra Nevada. Her drones were equipped with high-resolution cameras, infrared sensors, and advanced GPS mapping systems.
On September 15, 2024, at 3:42 p.m., her drone captured unusual geometric shapes deep inside a canyon more than 12 miles from the nearest trail. The terrain was extremely rugged, accessible only by technical climbing or helicopter.
The objects appeared artificial.
Dr. Martinez contacted the Mono County Sheriff’s Department. Detective Rodriguez received the coordinates.
Two days later, a specialized recovery team was helicoptered into the canyon. Ropes were required to reach the site.
Hidden beneath overhanging rock, protected from weather and scavengers, was a survival camp showing evidence of long-term habitation. A fire pit surrounded by stones indicated repeated use. Food containers were suspended from trees. Sleeping areas had been carved into the ground and insulated with pine needles and clothing.
The site was organized, not improvised.
Personal belongings confirmed the identity of the occupants. Dylan’s red backpack hung from a branch. Marcus’s park service jacket was folded near one of the sleeping areas. Items matched the inventory Linda had provided in 2006.
Beneath a carefully constructed stone cairn, investigators discovered a waterproof-wrapped leather journal written in Marcus’s handwriting. The first entry was dated October 15, 2006. The final entry was dated February 23, 2007.
Human remains were located at the site. Forensic examination showed no signs of violent trauma or animal predation.
The journal described events beginning with Dylan twisting his ankle near mile 7 of the trail. They had taken shelter in the canyon while his injury healed. Early entries documented routine survival efforts: rationing food, signaling for helicopters, and building fires.
After the first week, the tone shifted.
Marcus wrote about hearing voices at night calling their names. On October 28, 2006, he described discovering artificial structures deeper in the canyon—caves and stone formations built into the rock face. He referred to it as “the settlement.”
On November 3, 2006, he recorded meeting a group calling themselves “the Guardians.” There were 7 of them living in the settlement. Their leader, an older woman named Sarah, told Marcus that he and Dylan had been brought there for a purpose. She claimed they were protecting sacred sites in the mountains and that Marcus and Dylan had been chosen to join them.
The Guardians provided food, shelter, and assistance with Dylan’s ankle. They also made clear that leaving was not an option until Marcus and Dylan understood their responsibilities.
Subsequent entries described symbols carved into rock walls and chambers that Marcus said felt ancient. The Guardians taught Dylan navigation by stars, plant identification, and what they called “old knowledge.” Marcus initially expressed skepticism but gradually recorded acceptance of their worldview.
On December 1, 2006, Marcus wrote that the Guardians used concealment techniques to avoid detection, including misdirecting searchers with false trails and manipulating sound and light to obscure their location. He described how search helicopters could be redirected visually and acoustically.
Entries revealed Marcus struggling internally. He wrote about Linda believing them dead and about the justification offered by the Guardians—that protecting sacred places outweighed personal ties.
On January 25, 2007, Marcus wrote that he had decided to remain permanently with the Guardians. He described an initiation process involving relinquishing former identities.
The final entries documented preparation for a ritual involving tea made from local plants.
The final pages of the journal recorded events in February 2007.
On February 10, Marcus wrote that the initiation ceremony was scheduled for the following day. The ritual involved drinking tea prepared from plants intended to induce transformation. He expressed hesitation but stated it was too late to reverse course.
On February 20, 2007, he wrote that Dylan began convulsing during the ceremony. According to Marcus, the tea was stronger than expected. The Guardians lacked medical equipment. Dylan died in his arms.
The final entry, dated February 23, 2007, stated that Marcus intended to drink the same substance. He wrote that he could not live with the consequences of his decisions. He apologized to Linda and acknowledged responsibility.
Forensic analysis confirmed that Dylan’s remains contained plant alkaloids consistent with hallucinogenic compounds native to Sierra Nevada vegetation. Marcus’s remains showed higher concentrations of the same compounds.
Both deaths were consistent with poisoning by ingestion.
The campsite showed no recent signs of occupation beyond 2007. No evidence of the Guardians’ continued presence was found at the site. Their identities and current whereabouts remain unknown.
After 18 years, Marcus and Dylan Hoffman were recovered.
Linda Hoffman received confirmation of their deaths and the journal documenting their final months. The case file remains open regarding the alleged group described in Marcus’s writings.
The canyon where they lived for more than 4 months lies far from established trails. It had never been included in the original search grids due to its inaccessibility.
What began as a planned 3-day camping trip ended in prolonged isolation and two deaths.
The Sierra Nevada concealed their location for 18 years.
A wildlife survey drone revealed it.
