thermal · optional
Black Sand Basin
A compact basin offers Emerald Pool and Cliff Geyser—but is the first stop to release when the day slips.
Biscuit Basin closed until further notice
The closure related to the July 2024 hydrothermal explosion remains in place because hydrothermal activity is unpredictable. Pass the area; do not seek an alternate entrance.
Checked Jul 26, 2026
Yellowstone fire danger is HIGH
The dedicated NPS fire page and July 14 release list HIGH fire danger. No fire restrictions were in place when checked; both danger and restrictions can change.
Checked Jul 26, 2026
Parkwide chip sealing can move without notice
NPS says chip sealing can cause delays up to 30 minutes at various Yellowstone locations in 2026. Slow down on loose gravel and increase following distance.
Checked Jul 26, 2026
Chapter
Obsidian sand and bright pools
Narration
Obsidian sand and bright pools
What to notice
- Obsidian-derived black sand
- Emerald and Rainbow pools
- Cliff Geyser
Field notes
- Approach grades
- 9% and 12%
- Cliff Geyser
- Can erupt to about 40 feet