Colorado Department of Highways

The Colorado Department of Highways is the antecedent of today's Colorado Department of Transportation.

Many of its bridges are listed on the U.S. National Register of Historic Places.

[2][3] Studies of Colorado's historic bridges, to assess which ones could qualify for National Register listing, were conducted in 1983, 1987, 2000, and 2011.

The latter study evaluated "712 bridges and grade separations" which had been built during 1959 to 1968.

[4] Works (attribution) include:

Cherry Creek Bridge , built in 1948
Black Squirrel Creek Bridge , built in 1935