Keystone Arch Bridge
(Main Street Bridge, Keeseville Arch Bridge)
NBI Information
Location
State: New York
County: Clinton County
Feature Carried: NY-22 (Main Street)
Feature Crossed: Ausable River
Latitude, Longitude: 44.5053,-73.4810
Toll: On free road
Maintenance Responsibility: County Highway Agency
Structure Open, Posted, or Closed to Traffic: Posted for load (may include other restrictions such as temporary bridges which are load posted)
History
Year Built: 1842
Historical Significance: Bridge is on the National Register of Historic Places.
Year Reconstructed: None
Picture Date: June 22, 2023
Geometry
Lanes on Structure: 2
Lanes under Structure: 0
Skew: 0 degrees
Number of Main Spans: 1
Main Structure Type: Arch - Deck
Main Structure Material: Masonry
Number of Approach Spans: 0
Approach Structure Type: None
Approach Structure Material: None
Condition
Inspection Date: September 2022
Deck Condition: Not Applicable
Superstructure Condition: Fair
Substructure Condition: Fair
Channel Condition: Good
Culvert: Not Applicable
NBI Year: 2023
Bridge Information
The Keystone Arch Bridge, also called the Main Street Bridge and the Keeseville Arch Bridge, is one of the oldest bridges in the United States. It was built in 1843 and has carried traffic continuously since then. The bridge has obviously been renovated, but it still retains much of its historic integrity. It was designated a National Historic Civil Engineering Landmark in 1987.
The Ausable River is known to flood and has washed away many bridges throughout history. In 1842, this bridge was partially built when there was heavy rain and flooding. The stone from the partially completed arch and the falsework supporting it were washed away, and the project had to be restarted. Fortunately, this bridge has survived several other floods since then.
References
Keeseville Historic Bridges: https://keesevillehistoricbridges.com/keystone-arch-bridge/
Historic Bridges: https://historicbridges.org/bridges/browser/?bridgebrowser=newyork/keeseville/
ASCE: https://www.asce.org/about-civil-engineering/history-and-heritage/historic-landmarks/bridges-of-keeseville
