🌤 Weather at Casselman River Bridge State Park by season
| Spring | Summer | Fall | Winter |
|---|---|---|---|
| 24–68 °F | 52–80 °F | 28–73 °F | 17–39 °F |
Each range runs from the coldest monthly average low to the warmest monthly average high in that season (1991-2020 climate normals), measured at Meyersdale 2 SSW, 8 mi away, elevation 2,000 ft. Conditions at the park can differ from the station, especially where elevation differs — check a forecast before you go.
🌉 America’s Longest Single-Span Stone Arch Bridge (1813) — A National Road Engineering Marvel in Western Maryland — A historic state park preserving the 80-foot Casselman River Bridge, the longest single-span stone arch bridge in America when built in 1813, with picnic grounds, river access, and Appalachian mountain scenery — Garrett County, Maryland
Casselman River Bridge State Park preserves one of the most remarkable engineering achievements of early America — an 80-foot single-span stone arch bridge built in 1813 as part of the National Road (America’s first federally funded highway). When completed, it was the longest single-span stone arch bridge in the country, a technical marvel that carried wagon traffic westward across the Casselman River for over a century.
The bridge stands today as a National Historic Landmark, preserved in a small but scenic park along the Casselman River near Grantsville, Maryland — deep in the heart of Garrett County’s Appalachian highlands. The park offers picnic grounds, river access for wading and fishing, and a peaceful setting for photography and historical reflection.
The Bridge
| Feature | Details | Notes |
|---|---|---|
| Span | 80 feet | Longest single-span when built |
| Built | 1813 | Part of the National Road |
| Status | National Historic Landmark | Pedestrian-only today |
| Material | Stone arch construction | Local sandstone |
What to Do
| Activity | Details | Notes |
|---|---|---|
| Historic Bridge | Walk across 1813 landmark | Interpretive signs on-site |
| Photography | Stone arch over river | Best in morning light or fall foliage |
| Picnicking | Shaded picnic grounds | Tables, grills, restrooms |
| River Wading | Casselman River | Shallow areas below bridge |
| Fishing | Trout + smallmouth | MD fishing license required |
Best Time to Visit
| Season | Weather | Best For |
|---|---|---|
| Fall (Oct–Nov) | 35–58°F | Foliage framing the stone arch |
| Summer (Jun–Aug) | 62–82°F | River wading, picnicking, full access |
| Spring (Apr–May) | 40–65°F | Trout fishing, wildflowers |
| Winter (Dec–Feb) | 18–38°F | Snow on bridge — dramatic photos |
💰 Trip Cost Estimator
| Expense | Cost | Notes |
|---|---|---|
| Access | FREE | No entry fee |
| Day Trip | FREE | Walk across a 200-year-old stone arch |
Frequently Asked Questions
Can I walk across the bridge?
Yes. The bridge is closed to vehicles but open for pedestrians. You can walk across the 80-foot stone arch and view the Casselman River from above.
What was the National Road?
America’s first federally funded highway, built in the early 1800s to connect the Eastern seaboard to the Ohio River Valley. The Casselman bridge was one of its most ambitious engineering features.
Is it worth a special trip?
Combine it with nearby Deep Creek Lake (20 minutes south) for a full Garrett County day trip. The bridge alone is a quick but memorable stop for history and photography.
Nearby state parks: If you have extra time, New Germany State Park is a short drive away, and Big Run State Park is a short drive away.
🌉 1813 National Road Bridge
America’s longest single-span stone arch bridge when built — free access to a National Historic Landmark in western Maryland’s Appalachian highlands.
Wildlife & Nature
Casselman River Bridge SP — features the Casselman Bridge — an 1813 stone arch bridge that was the longest single-span stone arch bridge in the world when built. The park’s river, Appalachian forest, and historic structure support white-tailed deer, brook trout, and songbirds.
Nearby Attractions
Grantsville — adjacent — a historic National Road town. Spruce Forest Artisan Village — nearby. National Road (US-40) — at the park.
🐾 Dogs & Pets at Casselman River Bridge State Park
- Pets allowed? statewide rule
- Maryland state parks welcome leashed pets, but where they may go is set park by park under the Maryland Park Service Pet Policy — check each park's designated pet areas.
- Leash rule statewide rule
- 6 ft maximum in designated pet areas and 10 ft in undeveloped areas; off-leash under voice control only while swimming in designated areas
- Beaches & swim areas statewide rule
- At most parks pets are barred from sandy swim beaches from Memorial Day weekend through Labor Day; many parks allow shoreline swimming outside the swim beach
- Cabins & lodging statewide rule
- Most cabins are pet-free, but select parks designate pet-friendly cabins (e.g. Herrington Manor cabins 1-10, New Germany cabins 3-7)
- Statewide exceptions statewide rule
- Pets not allowed in park buildings or playgrounds; pets must be licensed and vaccinated
Are dogs allowed at Casselman River Bridge State Park?
Maryland state parks welcome leashed pets, but where they may go is set park by park under the Maryland Park Service Pet Policy — check each park's designated pet areas. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via dnr.maryland.gov. More: Maryland state parks guide · Dog rules in all 50 states compared
Park Location
Plan your gear for Casselman River Bridge State Park
From our editorial guides, matched to this park’s activities:
