Technical Data & Programs

Historic Bridge Program

CDOT has an active historic bridge program that has resulted in the development of a number of historic preservation tools:

Colorado Historic Bridge Inventories: Since 1983, CDOT has conducted several historic bridge inventories that have resulted in the evaluation of thousands of the state's historic bridges. These inventories have been used to streamline the administrative historic preservation process associated with bridge replacement projects, but have also provided valuable information about the historic significance of the state's many vehicular and railroad bridges. The next statewide historic bridge inventory will be completed in 2008.

1983 Historic Bridge Survey

  • Total of 544 bridges surveyed, including 139 on the Federal Aid Highway System ("on-system"), 337 off the Federal Aid System ("off-system"), and 51 Federal Aid Urban (FAU)
  • 64 bridges recommended as eligible to National Register of Historic Places based on point rating system
    Old Fruita Bridge (off system bridge built in 1906)
  • Pre-1945 bridge types surveyed: timber, iron, and steel trusses; iron, steel and concrete girders; steel, concrete and stone arches; concrete rigid frames

1987 Historic Bridge Survey:

  • Total of 7000 bridges evaluated (on and off system), primarily from post-1945 period
  • Resulted in 2 National Register eligible bridges and 16 potentially eligible bridges
  • Evaluated bridges less than 40 years old, of common structural types, or missing from off-system inventory

2000 Historic Bridge Inventory:

  • Evaluated 2158 bridges (on and off system)
  • Resulted in 208 National Register eligible bridges, 1453 not eligible. The remainder were designated "possibly eligible," indicating that each year CDOT will evaluate those bridge types to determine if there has been significant attrition, and if any "possibly eligible" structures should be elevated to "eligible" status as a result.

National Register Listed Bridges:

  • CDOT partnered with the Colorado Historical Society to nominate 29 of Colorado's highway bridges for listing on the National Register of Historic Places.

Highway Bridges in Colorado:

This database contains the National Register of Historic Places Multiple Property Documentation Form (MPDF) Highway Bridges of Colorado. The document describes the historical and technological evolution of Colorado's highway bridges in Colorado for National Register eligibility. In addition, photographs of bridges that have been determined to be field eligible for or listed on the National Register of Historic Places are also included. The photos are organized according to county.

Adopt-A-Bridge Program:

Historic truss bridges are made available for adoption by the public through the Adopt-A-Bridge Program, which is designed to assist in the preservation of bridges scheduled for replacement. Bridges that qualify for the program are advertised in a CDOT newsletter, the Colorado Historical Society newspaper, and local papers. Interested adopters are asked to provide a relocation proposal that includes information about proposed use, new location, and maintenance plans. To date the Adopt-A-Bridge Program has had limited success due to a lack of coordinated effort within CDOT as well as between CDOT and outside agencies and entities, but we are presently evaluating ways to revamp the program in a concerted effort to save more historic truss bridges from destruction. 

Red Cliff bridge, US Highway 24 (built in 1941)





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  • Dan Jepson
    Senior Staff Archaeologist
    Cultural Resource Program Manager
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  • Greg Wolff
    Assistant Staff Archaeologist
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    Senior Staff Historian
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  • Lauren Cooper
    Assistant Staff Historian
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    Assistant Staff Historian
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