A newly observed yosemite rock fissure on the western face of the iconic Royal Arches formation in Yosemite National Park has prompted heightened monitoring and visitor-access restrictions as of November 24, 2025. Experts report that the crack—first identified in mid-2023—continues to show signs of movement, prompting the park to maintain closures of several hiking trails and climbing routes to protect public safety.
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What we know so far
- The fissure was first reported by climbers in August 2023 on the western side of Royal Arches, near the popular climbing route known as Super Slide.
- Park officials concluded that a large pillar of granite had partially detached from the cliff face and that active cracking was occurring.
- As a precaution, a portion of the Valley Loop Trail beneath the formation and multiple climbing routes between Peruvian Flake West and Rhombus Wall were closed indefinitely.
- Recent geological monitoring confirms the crack remains unstable and continues to widen, keeping risk of rockfall elevated.
Why the yosemite rock fissure matters
This fissure is significant because:
- It lies within one of Yosemite Valley’s most visited corridors, making the hazard relevant to both casual visitors and experienced climbers.
- The detachment of a rock mass from a granite cliff can lead to sudden, large-scale rockfalls — a known cause of park injuries in recent years.
- The closure of climbing routes and trail segments has operational and tourism-implications for the park and surrounding businesses.
Current access & safety measures
Here’s how the park is managing the situation around the fissure:
- The climbing area on the western face of Royal Arches remains closed. Routes including Super Slide and Serenity Crack are off limits until further notice.
- A quarter-mile section of the Yosemite Valley Loop Trail beneath the cliff has been rerouted via a marked detour to keep hikers out of the hazard zone.
- Park geologists continue to monitor rock movement using lidar, crack gauges and visual inspections to assess stability over time.
- Visitors are advised to stay clear of barricaded areas and obey posted signage; aerial and ground-based monitoring indicate the risk remains elevated.
Key factors driving crack expansion
Geological and environmental processes influencing the fissure include:
- Freeze-thaw cycles: Water seeping into fractures freezes and expands, steadily widening the crack in the granite.
- Thermal stress: Day-to-night and seasonal temperature changes cause rock to expand and contract, triggering detachment of slabs.
- Inherent instability: Granite cliffs like those at Royal Arches are naturally prone to exfoliation — the gradual peeling off of rock layers — which weakens the structure over time.
What visitors should know
If you plan to visit Yosemite and might view or approach Royal Arches:
- Always check the park’s current alerts page for up-to-date information on closures related to the rock fissure.
- Do not attempt to bypass fences, signs or barricades near the affected area — climbing or hiking in the restricted zone puts you at high risk.
- For climbers: Routes in the closure zone remain off-limits until fully cleared by the park.
- For hikers: Use the designated detour on the Valley Loop Trail and avoid areas under the cliff face where rockfall hazard is active.
- Remember that conditions can change with little notice — weather, seismic activity or unseen cracking could restart movement at any time.
Wider implications of the fissure
The yosemite rock fissure is more than just a localized hazard. It reflects broader themes at play:
- The management burden for the park increases when key visitor zones are restricted or rerouted for geological safety.
- Tourism in the Yosemite Valley corridor may feel ripple effects if visitors alter plans due to the closures around Royal Arches.
- The fissure serves as a vivid reminder that even granite monoliths we view as permanent continue to evolve — and break down — under natural forces.
Bottom line
The yosemite rock fissure at Royal Arches remains an active geological hazard. Closures remain in place, monitoring is ongoing, and visitors must respect restrictions to ensure their safety.
If you’re planning a trip to Yosemite, stay informed about this fissure’s status and heed all instructions from park staff. Share your thoughts or questions below, and keep checking for further updates.