Regulations United States Yellowstone National Park
Obsidian Cliff
Hiking
Regulations on 30 October 2026
Signs at the site and later resolutions prevail; check the source.
-
Prohibited all year
Hiking · All year
In force on 30 October 2026
Obsidian Cliff is closed to all public access.
Published by National Park Service, 17 Sept 2026 · Yellowstone National Park Superintendent’s Compendium, September 2026
In Yellowstone National Park
Regulated zone
Yellowstone National Park
These hold everywhere inside the boundary, whether or not a site is marked.
-
Permit required
Caving · All year
In force on 30 October 2026
All caves within the park are closed to public use, except when a permit has been issued by the Superintendent.
Published by National Park Service, 17 Sept 2026 · Yellowstone National Park Superintendent’s Compendium, September 2026