Boulder County’s unincorporated areas comprise the rural, mountainous and plains communities that are not a part of any incorporated municipality. Unlike the municipalities within Boulder County which have a separately elected town board or city council, the unincorporated communities of Boulder County are governed by the ordinances and regulations adopted by the Board of County Commissioners.
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Many distinct and unique communities exist within the unincorporated areas of Boulder County, among them:
Located northwest Boulder County, Allenspark was established in 1870 in the midst of the gold rush.
Zip code: 80510
Coal Creek Canyon
Located partially in Southwest Boulder County, the Coal Creek Canyon community also resides in neighboring counties of Jefferson and Gilpin.
Zip code: 80403
Population: Approx. 2,400 (not all in Boulder County) according to the 2010 Census tract for the Coal Creek Census Designated Place
Eldora was established in 1896 as a gold mining camp and called Eldorado, which is Spanish for “the golden.” Eldora is located in southwest Boulder County within the Roosevelt National Forest and lends its name to Boulder County’s only local ski resort, Eldora Mountain Resort.
Zip code: 80466
Nestled in the valleys of the Flat Irons, Eldorado Springs was established in 1904 by a group of entrepreneurs who formed the Moffat Lakes Resort Company, creating the resort town of Eldorado Springs. Americans flocked to the springs in the early 20th Century for the rumored healing qualities of the water. Artesian water is still bottled and sold here. The nearby Eldorado Canyon State Park is famous for its rock climbing routes.
Zip code: 80025
Gold Hill is Colorado’s oldest continuously occupied mining town. It arose with the January 1859 gold discovery at Gold Run creek. Gold Hill is located about 10 miles to the northwest of Boulder, Colorado, perched on a mountainside above Left Hand Canyon at an elevation of 8,300 feet.
Zip code: 80302
Gunbarrel was established in the 1860s and named after Gunbarrel Road, the main stagecoach route between Boulder and Longmont. It is located northeast of Boulder and south of Longmont adjacent to Hwy 119 (along “the Diagonal.”)
Zip codes: 80301, 80503
The community of Hygiene (Est. 1861) was named after an early tuberculosis sanatorium, Hygiene Home. Water for the sanatorium was piped from a spring on Rabbit Mountain and was claimed to have valuable medicinal properties. The community lies just west of the City of Longmont.
Zip code: 80533
The Town of Niwot (Est. 1872) was named for Chief Niwot, an Arapaho leader in the Front Range at the time of the gold rush. Niwot is located northeast of Boulder and south of Longmont adjacent to Hwy 119 (along “the Diagonal.”)
Zip codes: 80503, 80544