A 53-year-old peak bagger has died after falling from a cliff band at the base of the Grand Central Couloir, on Mount Morgan North, a 13,005-foot peak in the Eastern Sierra south of Mammoth Lakes, following a days-long search that mobilized ground crews, helicopters and search dogs across the rugged Mono County wilderness.
Brian Seibert was reported missing after failing to return from a solo hiking trip on October 4, according to friends who alerted authorities, as reported by the San Francisco Chronicle. Mono County authorities initiated a search that quickly drew in Inyo County search teams, Yosemite National Park personnel, the California Highway Patrol and the California National Guard, per the same report. Rescuers confirmed on October 5 that Seibert had reached the summit of Mount Morgan after his name turned up in the mountain's summit register, and investigators later used cell phone forensics to determine he had descended along the same route he used to climb up.
Seven Teams Scour the Peak
By October 6, searchers had deployed seven teams that covered almost every aspect of Mount Morgan from top to bottom, the Chronicle's report notes, combining helicopter flyovers through the rocky High Sierra with air-scent search dogs on the ground. That day, a search helicopter crew spotted an anomaly from the air, leading rescuers to a single set of boot tracks descending the Grand Central Couloir, an east-facing gully that drops from the summit. Searchers followed those tracks to Seibert's body, finding he had fallen from a cliff band at the base of the couloir.
His body was recovered early Wednesday morning with help from a Yosemite National Park helicopter and a Friends of Yosemite Search and Rescue crew, according to the same account. The rescue drew on an unusually wide mix of agencies for a single recovery mission, mobilizing ground searchers and aerial resources from the Mono County Sheriff's Office, Inyo County Search and Rescue, California Highway Patrol Central Division Air Operations, the California National Guard and Yosemite National Park helicopter crews.
A Peak With a Twin, and a Technical Route
The Sierra Nevada actually holds two prominent summits named Mount Morgan, located roughly eight miles apart: Mount Morgan North, the 13,005-foot peak in Mono County where Seibert died, and Mount Morgan South, which climbs to 13,748 feet in neighboring Inyo County, according to onX Backcountry. Standard summit routes up Mount Morgan North involve Class 2 to Class 3 scrambling over unmaintained terrain, including steep rock chutes, loose scree and couloirs reached from the McGee Creek Trailhead or the Hilton Lakes Trailhead near Rock Creek Lake, per Mountain Project. Those routes involve scrambling over steep rock.
A Volunteer Force Built for the Eastern Sierra's Toughest Terrain
The search relied heavily on the Mono County Sheriff's Search and Rescue Team, an all-volunteer non-profit that operates under the Sheriff's Office to conduct free wilderness search and medical rescue missions across the high-elevation Eastern Sierra, according to MONOSAR.
Mono County's volunteer teams respond to wilderness search and rescue calls.
A Wider Pattern in Solo Wilderness Travel
Seibert's solo trip reflects a broader demographic pattern seen in national park mortality data. Of the 137 reported deaths on national park lands in 2025 for which sex was recorded, men accounted for 83 percent (114); those 114 men represented about 58 percent of all 198 reported deaths, according to 2026 National Park Service data analyzed by Outside Magazine. The analysis also discusses risk-taking and participation in solo and off-trail activities. Exactly what conditions Seibert encountered on the Grand Central Couloir, and what gear he carried for the descent, remain unknown.
