HistoricBridges.org Menu: HistoricBridges.org Menu:

We Recommend These Resources:
Bach Steel - Experts at historic truss bridge restoration.

HistoricBridges.org: Bridge Browser

Walpack Center Bridge

Walpack Center Bridge

Primary Photographer(s): Nathan Holth

Bridge Documented: November 8, 2015

View Photos
and Videos
View Maps
and Links

Key Facts

Facility Carried / Feature Intersected
Main Street Over Flat Brook
Rural: Sussex County, New Jersey: United States
Construction Date and Builder / Engineer
1889 By Builder/Contractor: Groton Bridge Company of Groton, New York

Technical Facts

Rehabilitation Date
Main Span Length
67 Feet (20.4 Meters)
Structure Length
69 Feet (20.9 Meters)
Roadway Width
11.8 Feet (3.6 Meters)
1 Main Span(s)
NBI Number

Historic Significance Rating (HSR)
View Information About HSR Ratings

Bridge Documentation

View Archived National Bridge Inventory Report - Has Additional Details and Evaluation

This bridge is an excellent example of the work of the Groton Bridge Company. It includes the company's distinctive top chord mounted plaque, cast iron pin caps, and latticed vertical members.

Information and Findings From New Jersey's Historic Bridge Inventory


The pin-connected Pratt pony truss bridge is supported on ashlar abutments. In 1944 the trusses were strengthened with the addition of welded plates to the vertical, diagonal, and lower chords. Outriggers were added, and channel sections were welded to the floor beams. The span is one of the few documented truss spans in the county, and it was fabricated by a notable company. The bridge was constructed within the period of significance of the district, and it is a contributing element under Criterion C.


The bridge carries a 1-lane road over a small stream in a wooded area located within the Delaware Water Gap National Recreation Area. The span is within the borders of Walpack Center Historic District, which is significant as a well-preserved example of an early rural service center dating from the mid-1800s to the early 1900s. Located in an isolated valley, the village marketplace, which was supported by local farmers, diminished with the advent of the automobile.

Physical Description

The pin-connected Pratt pony truss bridge supported on ashlar abutments spans 70' and carries an 11'-6" width roadway. The truss members are standard sections, and they have been strengthened with welded plates. Outriggers were added to the trusses, and channel sections were welded to the floor beams. The deck was replaced with a metal grate deck. The dates of the alterations to the span are not documented. No plans for the bridge were located.

Historical and Technological Significance

The Pratt pony truss bridge, located in the Walpack Center Historic District, was constructed in 1889 by the Groton Bridge & Manufacturing Co., as is documented on a plaque located on top of one of the trusses. The bridge is significant because it is a documented example of an uncommon bridge type constructed by a noted bridge manufacturer. It was built within the period of significance of the district, and it is a contributing element (Criteria A & C). The Groton Bridge & Manufacturing Company, of Groton, New York, was formed in 1877 under the name of the Groton Iron Bridge Company. The company was formed as the result of a merger between the Groton Iron Works, a blacksmith shop owned by Charles and Lyman Perrigo, and the Groton Separator Works, a manufactory of agricultural equipment owned by Daniel Spencer and Frederick Avery. It became a major bridge manufacturer primarily constructing small Pratt truss bridges in New York State. The firm was run by Ellery Colby and Frederick Avery during its first ten years of operation. Colby was a significant figure in New York State bridge building who later formed the Owego Bridge Company. In 1887, the name of the firm was changed to the Groton Bridge and Manufacturing Company, and it expanded operations. During this period, the company constructed many spans throughout the nation, the largest being an eleven-span bridge in Little Rock, Arkansas in 1896, and a multi-span crossing of the Anacostia River at Pennsylvania Avenue in Washington, D.C. in 1890 (replaced in 1936 by the John Phillip Sousa Bridge). In 1899, the firm became part of the American Bridge Company, and continued operation, primarily in New York State, until it folded in 1920. The Walpack Center Historic District is an example of one of the first forms of urbanism in the country, the rural service center. Rural service centers thrived from the mid-nineteenth century through the early twentieth century, providing a marketplace for the local agricultural industry. Walpack Center was geographically isolated, located in a valley between two ridges of the Kittatinny Mountains. The geography of the area dictated a need for a local marketplace because travel was difficult. The farmers in the area depended on the local market to sell their goods, and the local people depended on it to obtain goods. With the advent of the automobile, travel became easier and this interdependence no longer existed. The town did not expand with increased transportation, as other service centers did, because of its isolated location. Building in the town came to almost a complete end in the early 1900s, and the town retains much of its late 18th century character. The architecture is not sophisticated, but rather ordinary, reflecting the lifestyle of the rural town during its peak. The bridge is located at the edge of town within the historic district, and it was constructed in 1889, during the period of significance.

Boundary Description and Justification

The bridge is an eligible contributing resource to the National Register-listed Walpack Center Historic District (1980). The bridge is completely within the boundaries of the historic district delineated in the nomination (refer to NR Sussex Co. File at HPO). The eligible resource includes the bridge as well as its surroundings.


Pamela Thurber, "The Groton Iron Bridge Company," Historic Ithaca & Tompkins, NY, Newsletter Fall 1983, New Series Vol. 1,2, pp. 1-4. Office of New Jersey Heritage. Sussex County, Walpack File.

Bridge Considered Historic By Survey: Yes


Photo Galleries and Videos: Walpack Center Bridge

View Photo Gallery
Bridge Photo-Documentation
Original / Full Size Photos
A collection of overview and detail photos. This gallery offers photos in the highest available resolution and file size in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer
View Photo Gallery
Bridge Photo-Documentation
Mobile Optimized Photos
A collection of overview and detail photos. This gallery features data-friendly, fast-loading photos in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer


Maps and Links: Walpack Center Bridge

Coordinates (Latitude, Longitude):

View Bridge Location In:

Bridgehunter.com: View listed bridges within a half mile of this bridge.

Bridgehunter.com: View listed bridges within 10 miles of this bridge.

Google Maps

Google Streetview (If Available)

Bing Maps


Apple Maps (Via DuckDuckGo Search)

Apple Maps (Apple devices only)


HERE We Go Maps

ACME Mapper

Waze Map

Android: Open Location In Your Map or GPS App

Flickr Gallery (Find Nearby Photos)

Wikimedia Commons (Find Nearby Photos)

Directions Via Sygic For Android

Directions Via Sygic For iOS and Android Dolphin Browser

USGS National Map (United States Only)

Historical USGS Topo Maps (United States Only)

CalTopo Maps (United States Only)

Home Top


About - Contact

© Copyright 2003-2022, HistoricBridges.org. All Rights Reserved. Disclaimer: HistoricBridges.org is a volunteer group of private citizens. HistoricBridges.org is NOT a government agency, does not represent or work with any governmental agencies, nor is it in any way associated with any government agency or any non-profit organization. While we strive for accuracy in our factual content, HistoricBridges.org offers no guarantee of accuracy. Information is provided "as is" without warranty of any kind, either expressed or implied. Information could include technical inaccuracies or errors of omission. Opinions and commentary are the opinions of the respective HistoricBridges.org member who made them and do not necessarily represent the views of anyone else, including any outside photographers whose images may appear on the page in which the commentary appears. HistoricBridges.org does not bear any responsibility for any consequences resulting from the use of this or any other HistoricBridges.org information. Owners and users of bridges have the responsibility of correctly following all applicable laws, rules, and regulations, regardless of any HistoricBridges.org information.

Admin Login