Interactive Maps
Mount Vernon to Anacostia River
Search Potomac Sites
Also Explore
| The Hudson River Guide | The Delaware River Guide |
| The Connecticut River Guide | |
Sideling Hill Creek
Tributary
Sideling Hill Creek starts in Pennsylvania and meanders 25.2 miles to reach the Potomac. The Creek is the boundary between Allegany and Washington Counties. Sideling Hill Creek has a story shaped by both deep geologic time and the remarkable ecological integrity that still defines it today. Flowing off the steep shale and sandstone ridges of the Ridge-and-Valley province, the creek descends from Pennsylvania into Western Maryland before joining the Potomac, carving through dramatic Devonian formations that mirror the famous Sideling Hill road cut nearby. Its watershed remains roughly 80% forested and sparsely populated, a level of intactness that has preserved exceptionally high water quality and diverse aquatic life. Along its steep shale barrens grow rare, endemic plants found nowhere else, including the federally endangered Harperella, protected within designated Natural Heritage Areas. This blend of rugged geology, isolation, and careful conservation has allowed Sideling Hill Creek to remain one of Maryland's healthiest stream systems,
Suggested Links
Contact Information
Maryland Department of Natural Resources
580 Taylor Ave.
Annapolis MD 21401
877-620-8DNR
Website