There are more than 1,500 properties and historic districts in the U.S. State of Colorado listed on the National Register of Historic Places. They are distributed over 63 of Colorado's 64 counties; only the City and County of Broomfield currently has none.
The Phoenix Iron Works, located in Phoenixville, Pennsylvania, was a manufacturer of iron and related products during the 19th century and early 20th century. Phoenix Iron Company was a major producer of cannon for the Union Army during the American Civil War. The company also produced the Phoenix column, an advance in construction material. Company facilities are a core component of the Phoenixville Historic District, a National Register of Historic Places site that was in 2006 recognized as a historic landmark by ASM International.
The Slate Creek Bridge is a riveted steel Parker pony truss bridge spanning the Blue River 9 miles (14.5 km) north of Silverthorne, Colorado. It is named after the road it carries, Slate Creek Road. The bridge was rehabilitated in 1951. This rare example of an uncommon truss type was listed on the National Register of Historic Places in 1985.
The 19th Street Bridge is a two-span through Pratt truss road bridge in Denver, Colorado, over the South Platte River, now used for pedestrians. It was built in 1888 to replace a wooden structure and carried automobile traffic until 1986. The bridge is listed on the National Register of Historic Places.
The Minnequa Steel Works Office Building and Dispensary are historic buildings in Pueblo, Colorado. The main office building served as headquarters of Colorado Fuel and Iron Company. The medical dispensary building served as a medical clinic for treatment of minor injuries and illnesses, and in later years, as both clinic and personnel office for the Colorado Fuel and Iron Company. Opened in 1902, the six-room Spanish Mission style building contained waiting, drug, consultation, surgical and storage rooms, in addition to sleeping and office quarters for attending physicians. In 1902, as the company payroll exceeded 5,000 employees, the Dispensary handled an average of seventy-five cases daily. As employee numbers grew, medical staff also began treating families of employees. The building was used as a medical building for mill employees until the early 1990s. The Minnequa Steelworks Office Building, built in 1901, served as company headquarters until the early 1990s. Here, many office functions occurred including purchasing, finance, payroll, engineering, and other administrative functions. The building complex was listed on the National Register of Historic Places in 2002, amended to the National Level of Significance of the National Register of Historic Places in 2008, and was designated a National Historic Landmark in 2021. Owned and operated by the Steelworks Center of the West, the medical dispensary building is the home of the Steelworks Museum of Industry and Culture, which opened on January 19, 2007. The museum's exhibits include the local history of coal mining, steel production, railroads, labor, and the impact of the Colorado Fuel and Iron Company on the region. The main administration building will serve as the second phase of the Steelworks Museum of Industry and Culture in the coming years.
The Hayden Arch Bridge is a concrete arch bridge on old US 14/US 16 in Park County, Wyoming, United States, that is listed on the National Register of Historic Places {NRHP).
The Sheely Bridge, originally known as the Carbondale Bridge, carries pedestrian traffic across the Roaring Fork River at Mill Street Park in Aspen, Colorado, United States. It is a short steel truss bridge originally located downstream in Carbondale and later moved to its present location.
Four historic bridges on the Big Thompson River in Larimer County, Colorado survived its flood of 1976, but since have lost most of their historic integrity. They were built in 1933 and 1937. All four were listed on the National Register of Historic Places in 2002, and two were delisted in 2010.
Monarch Engineering Co. was an American firm of Denver, Colorado, active in engineering and construction services. John A. Crook and his brother, Guy A. Crook of Falls City, were founders of the Monarch Engineering company which had its origin and main offices at Falls City, with offices in Kansas City, and Denver. Under the management of these men the Monarch Engineering company had risen to become an important and prosperous concern and a vast amount of bridge construction, city paving, irrigation-dam building, and public building work has been done under their supervision. Within ten years after the firm had been in operation, or since 1908, its activities constantly increased and in 1917 they purchased the Denver Steel and Iron Works in order to facilitate the material supply part of the construction work in which they were engaged.
The ETD Bridge over Green River is a steel girder bridge near Fontenelle, Wyoming, which carries Sweetwater County Road CN4-8SS over the Green River. The bridge is a replacement for a historic Pratt through truss bridge built in 1913 by the Colorado Bridge and Construction Company. The 150-foot-long (46 m) bridge was one of the longest Pratt through truss bridges built in the early stages of Wyoming bridge construction.
The Labo Del Rio Bridge, over the Piedra River near Arboles, Colorado, was designed and built in 1913 by the Missouri Valley Bridge Company with steel by the Illinois Steel Company. It is a Pratt through truss bridge. It has also been known as Bridge over Piedra River. The bridge cost the state $3,395. It was listed on the National Register of Historic Places in 1985.
The San Luis Bridge, also known as State Bridge or Bridge over Culebra Creek, is a historic open spandrel arch bridge that crosses Culebra Creek in San Luis, Colorado. It was built in 1911 as a road bridge, but now serves pedestrian traffic. It is listed on the National Register of Historic Places.
County Line Bridge is a historic structure located in a rural area west of Columbus Junction, Iowa, United States. The Louisa County Board of Supervisors approved the petition of Thomas Anwyl in April 1893 to build a bridge over Long Creek on the Louisa-Washington county line. They awarded a $1,174 contract to the Gillette-Herzog Manufacturing Company of Minneapolis to build two bridges. The second span was the Gipple's Quarry Bridge over Buffington Creek in Elm Grove Township. The bridge span is supported by cast iron columns that were manufactured by the Cast Iron Pile and Bridge Company of Keosauqua, Iowa. The steel components were rolled by Carnegie, Gillette-Herzog in Pittsburgh. The pony truss bridge is typical of those built in the same era in Iowa, however, like Gipple's Quarry Bridge it has an unusual lower chord configuration with end panels that slope downward from the bearing shoes to the center panels. It has subsequently been abandoned. The bridge was listed on the National Register of Historic Places in 1998.
The Mountain States Telephone and Telegraph Company in Miles City in Custer County, Montana was built in 1914. Also known as the Rowland, Thomas & Co. Building, it includes Renaissance Revival. It was listed on the National Register of Historic Places in 1988.
The Hay's Ranch Bridge, in Rio Blanco County, Colorado near Meeker, Colorado, was built in 1900–01. It was listed on the National Register of Historic Places in 1985.
The Morley Bridge, also known as the Romley Bridge, located near Romlee in Chaffee County, Colorado, is a wrought-iron pin-connected Pratt truss bridge that was built in 1881. It was listed on the National Register of Historic Places in 2003.
The Little Thompson River Bridge, in Weld County, Colorado near Berthoud, Colorado, was built in 1938. It was listed on the National Register of Historic Places in 2002.
The G. W. & W. M. Clayton Building, also known as the Granite Hotel, Granite Building and the Clayton Building, is an 1882 commercial building in Denver, Colorado and is a Denver Landmark. It is a four-story building which was built in 1882 on the site of the first building in Denver, a log cabin. It was built to host the M.J. McNamara Dry Goods Company. G. W. & W. M. Clayton is inscribed near the top of the building for businessman George W. Clayton and his brother William M. Clayton, who served as mayor of Denver. The Denver Public Library has a photograph of the G. W. & W. M. Clayton Building.
The Black River Bridge near Carrizo, Arizona was funded in 1911 and built in 1912. It was listed on the National Register of Historic Places in 1988. It spans the Black River, bringing an army road, now Indian Route 9, over the river from Fort Apache to the railroad at the former town of Rice, Arizona.
The St. Charles Bridge near Pueblo, Colorado which brings Pueblo County Road 65 over the St. Charles River, was built in 1924. It is a filled spandrel arch bridge. It was listed on the National Register of Historic Places in 1985.
