National and State Register

Big Thompson River Bridges I & II

Larimer County

Constructed in 1937, both of the single spans of this steel rigid connected camelback pony truss extend for 100 feet across the Big Thompson River.

A black and white photo of one of the bridges with truss and water running beneath in the background are rising hills covered in trees.

Big Thompson River Bridges I & II 

Designed by the Colorado Department of Highways, fabricated by Midwest Steel & Iron Works, and built by M.E. Carlson, the bridges continue to provide an important transportation link along the route to Rocky Mountain National Park.  These bridges are two of four located on the upper Big Thompson River, comprising the last surviving group of such trusses in the state.