This was one of a pair of bridges built to support construction of the Thompson Falls Hydro Dam Project, also of 1911 vintage. Originally a vehicle bridge, the Parker-Pratt deck truss bridge served areas to the south of the Clark Fork River until its closure due to deterioration in 1979. It is 80 feet high and 588 feet long.
The only bridge of its kind in Montana still standing, it was entered in the National Register of Historic Places in 1986 as a contributing structure to the Thompson Falls Hydroelectric Dam Historic District.
High Bridge Facts
Longest bridge of its kind still standing in Montana.
Included on the National Register of Historic Places in 1986 as part of the "Hydroelectric Dam Historic District".
Length: 588 feet
Style: Parker/Pratt Deck Truss
Deck Width: Originally 18 feet wide: reconstructed to 12 feet wide.
Spans:
(1) 55-foot, 3-panel Parker Deck Truss
(1) 160-foot, 9-panel Pratt Deck Truss
(2) 127-foot, 7-panel Pratt Deck Trusses
(1) 65-foot, 4-panel Pratt Pony Truss converted to a Deck Truss
(3) Wood stringer spans replaced by one steel span during renovation
From a plaque at the bridge
High Bridge Rehabilitation
Is it possible to connect with the past through the future? High Bridge across the Clark Fork River at Thompson Falls is an important local landmark and
the only remaining bridge of its kind in Montana. The 588-foot long, 80-foot high, Parker-Pratt deck truss bridge was built in 1911 to provide access during construction of hydroelectric dams on the Clark Fork River. Over the years, the single-lane structure was superseded by other, newer bridges. It fell into disrepair and was eventually closed in 1979. Working with Sanders County, Morrison-Maierle developed plans and specifications for the rehabilitation of the structure as a pedestrian bridge. Select components, including beams, connections, piers, decking and railings were replaced, cleaned, painted or otherwise faithfully restored, returning the bridge to full, non-vehicular use. The greatest challenge was successfully striking a balance between the existing geometry of the structure with today’s materials and engineering design standards. Sanders County’s long-time goal to “Bridge the Gap” was realized within their budget and the High Bridge has become a popular local attraction and historic landmark.
From Morrison-Maierle, Inc.
Sanders County commissioners announced a celebration ceremony in honor of the completion of the Historic High Bridge Renovation in Thompson Falls, Mont. The dedication of the newly renovated bridge will take place on Saturday, May 8 at 3 pm on the north side of the High Bridge on Island Park.
The High Bridge was built in 1911 to support construction of the Thompson Falls Hydroelectric Dam. It was the primary route across the Clark Fork River at Thompson Falls until 1928, when a new bridge was built over the river at Birdland Bay. It remained a key link to access for the Cherry Creek area until the early 1970s, when it was closed to vehicular use due to deterioration of the decking. Further deterioration closed the bridge to all use by the late 1970s. It’s the longest bridge of its kind that is still standing. It was included on the National Register of Historic Places in 1986 as part of the Thompson Falls Hydroelectric Dam Historic District.
Now, over 30 years after it was closed to use, the bridge has been returned to its former glory and will be officially re-opened as a new pedestrian and bicycle connection between Thompson Falls and the south side of the Clark Fork River. Over the past decade, the county commissioners worked diligently to secure funding for the renovation of this historic structure. And, for the last two-and-a-half years, a group of citizens from throughout Sanders County have met as a steering committee to assist the commissioners in making this project a reality.
From the River Journal