Geology
Millard County, UT
Approximate location — plotted from published sources, not a site visit, and not a guarantee of access.
A ~15,500-year-old tuff cone that erupted under rising Lake Bonneville in the Black Rock Desert. Wave-cut beaches and the famous white “Lace Curtain” cliff expose palagonitized ash; UGS GeoSights highlights the underwater Surtseyan eruption story and fault-fed volcanism still active in the field (young basalt flows nearby).
| Region | Millard County, UT |
|---|---|
| Coordinates (approx.) | 39.1313, -112.5516 |
| Access | Clear Lake Bird Refuge road east from SR-257 south of Delta, then signed spur toward the butte (UGS directions) |
| Rock | Basaltic tuff cone with Bonneville-level wave-cut shelf and palagonite |
| Agency | BLM public lands / adjacent Clear Lake refuge corridor |
| Also called | Pavant Butte, Sugarloaf |
Public recreation data — BLM & Recreation.gov (RIDB). Verify current access, fees, and seasonal closures before traveling.
Map preview
The interactive map and its tiles load only when requested.
Plan ahead. Leave no trace. Verify current access before traveling.