Colfax Avenue is the main street that runs east–west through the Denver metropolitan area in Colorado. As U.S. Highway 40, it was one of two principal highways serving Denver before the Interstate Highway System was constructed. In the local street system, Colfax lies 15 blocks north of the zero meridian street of Ellsworth Avenue, and would thus it otherwise be known as 15th Avenue (Avenues north of Ellsworth are generally numbered numerically.) The street was named for former Vice President Schuyler Colfax. At just under in length, it is known as the "longest continuous commercial street in the United States".
Geography
From west to east, Colfax Avenue starts at Heritage Road in Golden as U.S. Highway 40 and the I-70 Business Loop, and continues east through Lakewood and enters Denver at Sheridan Boulevard. U.S. Highway 287 joins Colfax just west of I-25, and follows Colfax east through Denver and Aurora. In downtown Denver, near the Colorado State Capitol, the designation changes from West Colfax Avenue to East Colfax Avenue at the intersection with Broadway. It continues as East Colfax Avenue for the remainder of the route. In eastern Aurora, Colfax Avenue and Picadilly Road meet, with the I-70 business loop and the two U.S. highways following the I-70 route eastward via a new I-70 Picadilly Road (DDI) interchange, which replaced the old I-70 Colfax intersection. Colfax continues eastward from Picadilly Road via Colfax I-70 frontage road to E-470. East Colfax Avenue with Colfax signage continues east passing through the complex E-470 I-70 interchange, appearing as a frontage road of I-70 on most maps. About one block east of E-470 a north turn continues Colfax eastward separating Colfax from East 14th Avenue. At an interchange (I-70 Exit 292), Colfax Avenue travels concurrently as State Highway 36 and continues east from Aurora through Bennett to end at Headlight Road in Strasburg.
In the area between E-470 and Colfax joining State Highway 36 a new Aerotropolis Parkway interchange, under construction in December 2025, added about one half mile to the length of Colfax Avenue as it routes around the new interchange area.
Colfax Avenue cuts through Original Auraria, the city's historic core, and skirts the southern edge of downtown Denver. Because of the dense, mixed-use character of the development along Colfax Avenue, the Regional Transportation District bus route 15 - East Colfax has the highest ridership in the RTD system. In 2006, the first Colorado Colfax Marathon was held, traversing the length of Colfax Avenue through the three cities.
It's become legend that, at some time in the 1970s, Playboy magazine called Colfax "the longest, wickedest street in America", due to the prevalence of drugs, sex work, violence and poverty, but attempts to source the actual quote have failed. Periodically, Colfax undergoes redevelopment by the municipalities along its course that bring in new housing, businesses and restaurants.
History
East Colfax
1860–1890: Elite residential street
Colfax's precursor, Grand Avenue, was established in along what was the southern boundary of central Denver. It was established as an east–west running baseline street along with the north–south running Broadway, to border new eastern and southern districts for the city. In 1868, Grand was renamed "Colfax" to honor U.S. House Speaker Schuyler Colfax who later became Ulysses Grant's Vice President. Colfax had visited Denver in 1865, and locals may have named the street after him to gain national support from the prominent Indiana congressman for Colorado's ongoing statehood initiative.
Denver's population rapidly increased with the arrival of railroads, growing from 4,759 in 1870 to 106,713 in 1890. The area along Colfax developed unevenly: by the end of 1879, the area east of Broadway and north of Colfax was still mostly open prairie, but the area between Grant and Ogden Streets had become a prominent residential area. By 1887, residents and property owners along Colfax began pushing for better transportation options.
A cable railway was built in 1886 to connect Grant and Colfax with downtown Denver. The system was eventually replaced with streetcars, which facilitated more efficient transportation and encouraged development away from the city center. The construction of the State Capitol building in 1886 also had a positive impact on the development of the corridor, and by 1890, the Colfax Avenue Railway Company had extended its line to Montclair.
1890–1910: Conversion to denser housing
The Panic of 1893 led to an economic depression in Denver, and many large houses along Colfax were converted into multi-family units. The once lavish and expensive homes along East Colfax and in Capitol Hill were no longer easy to maintain, and owners of the single-family mansions were forced to rent out rooms in their homes to temporary workers. As the economy recovered, apartment buildings were constructed, raising concerns among residents about the impact on property values and neighborhood quality. Three buildings still in existence from this early period are The Colonnade, Alta Court (formerly the Altamaha Apartment Building), and the Hamilton. The cultural and demographic shift, from single-family mansions toward boarding houses and rental property for the transient middle class, marked a shift in the demographics of East Colfax.
1910–1940: Automobiles and commerce
The development of East Colfax was significantly influenced by the automobile, with the number of cars increasing exponentially from the mid-1910s to the 1920s. Increasing traffic led to the corridor becoming more commercial and the street was paved sometime prior to 1920. It part of the transcontinental U.S. Route 40 in the mid-1920s. Various groups sought to make East Colfax the best road in the state, transforming it into the gateway to Denver for tourists visiting by automobile from the East. It remained the gateway to Denver until i-70 was built in the 1950s.
Denver's 1925 zoning code designated most of East Colfax as commercial or business, and the city's 1929 Master Plan acknowledged its transformation from a residential street to a business artery. This change led to a boom in commercial building construction in the 1920s, with various structures being erected along the avenue. While construction declined during the Great Depression and World War II, some commercial buildings and apartments continued to be built.
Bluebird Theatre
Built in 1913 as the Thompson Theatre, the Bluebird Theatre was given its current name by theatre mogul Harry Huffman in 1921. Huffman hosted a successful War Bonds contest during WWII, but the theater faced challenges in the post-war years, eventually screening low-budget and adult films until its closure in 1987. In 1994, Chris Swank and Evan Dechtman purchased the Bluebird and renovated it into a live music venue with tiered levels and a bar, aided by federal funding. AEG assumed control of the property in 2006. The Bluebird Theater is known for an intimate atmosphere and contributing to the cultural heritage of Colfax Avenue. Designed by architect Harry W. J. Edbrooke, the two-story building features a light tan brick exterior with red terra cotta accents and a lighted marquee.
Establishments on the National Register of Historic Places
These places along Colfax Avenue have been listed on the National Register of Historic Places:
- Basilica of the Immaculate Conception
- Civic Center Historic District
- Denver Mint
- Ogden Theatre
- White Spot Restaurant
- West Side Court Building
- East High School
- Davies' Chuck Wagon Diner
- Jewish Consumptives' Relief Society
- Hill Section, Golden Hill Cemetery