| Huntley Mountain Formation | |
|---|---|
| Stratigraphic range: Late Devonian to Early Mississippian | |
 The Haystacks of Loyalsock Creek in Laporte Township, Sullivan County, Pennsylvania are a quartzite bed of the Huntley Mountain Formation | |
| Type | sedimentary |
| Underlies | Burgoon Sandstone |
| Lithology | |
| Primary | sandstone, shale |
| Location | |
| Region | Appalachian Mountains |
| Extent | Pennsylvania |
| Type section | |
| Named for | Huntley Mountain, Lycoming County, Pennsylvania |
| Named by | Berg and Edmunds, 1978 |
The Huntley Mountain Formation is a late Devonian and early Mississippian mapped bedrock unit in Pennsylvania, in the United States.