How to See the Thomas Viaduct Near Arbutus
26 October 2026
Just south of Arbutus, in the historic community of Relay, stands one of the most remarkable bridges in America. The Thomas Viaduct, completed in 1835, is the world's oldest multiple stone-arched railroad bridge, and trains still cross it today. The easiest way to see it up close is from the Avalon Area of Patapsco Valley State Park, a quick drive from downtown Arbutus.
What is the Thomas Viaduct?
It is a curving granite railroad bridge that carries trains across the Patapsco River between Baltimore and Howard counties. It was designed by Benjamin H. Latrobe, son of the famous architect of the same name, and it has long carried the nickname "Latrobe's Folly." Nearly two centuries later, it is still in service.
| Fact | Detail |
|---|---|
| Completed | 1835 |
| Designer | Benjamin H. Latrobe |
| Arches | 8, each spanning about 58 feet |
| Length | 612 feet |
| Height above the river | About 59 feet |
| National Historic Landmark | Since 1964 |
Source: Maryland Historical Trust
Where is the best place to view it?
Head to the Avalon Area of Patapsco Valley State Park at 5120 South Street. Enter off U.S. Route 1 at South Street, just north of Elkridge, and follow the park road to the contact station. The viaduct is visible right from the contact station area. The railroad is still active, so enjoy the view from a distance and never walk on or near the tracks.
What else is there to do in the Avalon Area?
Make an afternoon of it. The Avalon Area has picnic shelters, playgrounds, Lost Lake, the eastern end of the Grist Mill Trail, Cascade Falls, and the William Offutt Johnson History Center, one of the few buildings left from the old Avalon Iron and Nail Works.
When can I visit and what does it cost?
The Avalon Area is open from 9 a.m. to sunset. There is a day-use fee, and current amounts are on the Maryland Park Service fee page. Fall is a gorgeous time to go, with the river valley in full color. Questions? Call the park at 410-461-5005.
Why does it matter for people living in Arbutus?
The viaduct is a big part of why this corner of Baltimore County feels so special. Relay grew up around the railroad, and you can still see Victorian homes from that era in the neighborhood. Having a National Historic Landmark and a huge state park on your doorstep is one of the best perks of living here. Learn more on our Neighborhoods page.
Frequently Asked Questions
Where is the Thomas Viaduct?
It crosses the Patapsco River at Relay, just south of Arbutus. You can view it from the Avalon Area of Patapsco Valley State Park, 5120 South Street.
Is the Thomas Viaduct still used by trains?
Yes. It has been in continuous railroad service since 1835.
How old is the Thomas Viaduct?
It was completed in 1835. It is considered the world's oldest multiple stone-arched railroad bridge.
Can I walk on the Thomas Viaduct?
No, it is an active railroad. Enjoy the view from the park and stay off the tracks.
Is there a fee to visit the Avalon Area?
Yes, there is a day-use fee. Current fees are listed on the Maryland Park Service website.
Disclaimer: Facts come from the Maryland Historical Trust and the Maryland Department of Natural Resources as of October 26, 2026.
Love the Idea of Living Near the Park?
I would be happy to show you homes close to Patapsco Valley State Park and historic Relay. Call or text me at 443-421-6855.
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