Conant Creek Pegram Truss Railroad Bridge

Summary

The Conant Creek Pegram Truss Railroad Bridge, in Fremont County, Idaho near Grainville, Idaho and Ashton, Idaho, was built in 1894. It brought a railroad over the Conant Creek, 1 mile south of the junction of Squirrel Rd. and the old Ashton-Victor railroad spur tracks. It is a Pegram truss bridge, designed by George H. Pegram. It was listed on the National Register of Historic Places in 1997.[1]

Conant Creek Pegram Truss Railroad Bridge
As a rail trail bridge in 2014
Conant Creek Pegram Truss Railroad Bridge is located in Idaho
Conant Creek Pegram Truss Railroad Bridge
Conant Creek Pegram Truss Railroad Bridge is located in the United States
Conant Creek Pegram Truss Railroad Bridge
Nearest cityGrainville, Idaho
Coordinates44°00′52″N 111°21′53″W / 44.014317°N 111.364644°W / 44.014317; -111.364644
Arealess than one acre
Built1911
ArchitectGeorge H. Pregram
Architectural stylePregram truss bridge
MPSPegram Truss Railroad Bridges of Idaho MPS
NRHP reference No.97000756[1]
Added to NRHPJuly 25, 1997

It now carries the Ashton-Tetonia Trail, and is known as the Conant Creek Trestle.[2]

It is a 780 feet (240 m) long bridge, spanning across four supporting steel towers, built to carry a single railroad track. The towers, fabricated in 1911 by the American Bridge Company. The two center towers are about 107 feet (33 m) high, and with 30 feet (9.1 m) of truss above, the total distance from base to railroad bed is 137 feet (42 m). The three central spans are pin-connected Pegram truss deck spans, each 164 feet (50 m) long and 14 feet (4.3 m) wide, with a maximum depth of 30 feet (9.1 m). At each end are steel deck girders 60 feet (18 m) long at the north end and 30 feet (9.1 m) at the south end, and then timber approach spans 60 and 45 feet long.

It was built in 1911 with Pegram spans that had been fabricated in 1894 by the Union Bridge Company of New York, and had been used previously at a Snake River crossing at American Falls, Idaho. The trusses were reinforced in 1916 with an additional, similar span along the centerline, manufactured by the American Bridge Company. In 1927 the steel girders were put into place, replacing original 1911 timber Howe trusses; these girders are believed to have been fabricated by Paxton & Verling Iron Works.[3]

The rails were removed when the line was abandoned, several years before the 1997 National Register listing.[3]

References edit

  1. ^ a b "National Register Information System". National Register of Historic Places. National Park Service. November 2, 2013.
  2. ^ Google maps.
  3. ^ a b Donald W. Watts (May 20, 1997). "National Register of Historic Places Registration: Conant Creek Pegram Truss Railroad Bridge". National Park Service. Retrieved January 9, 2020. With accompanying two photos from 1990