Red Cliff (sometimes spelled Redcliff) is a statutory town in Eagle County, Colorado, United States. The population was 267 at the 2010 census. The town is a former mining camp situated in the canyon of the upper Eagle River just off U.S. Highway 24 north of Tennessee Pass. The town site is concealed below the highway (which passes over the Red Cliff Truss Bridge) and is accessible by a side road leading to Shrine Pass in the Sawatch Range. It was founded in 1879 during the Colorado Silver Boom by miners from Leadville who came over Tennessee Pass scouting for better prospects. The name derives from the red quartzite cliffs surrounding the town. As the first community in the Eagle Valley, it served temporarily as the first county seat of Eagle County (formed out of Summit County in 1883) until the relocation of the county seat to Eagle in 1921.
Red Cliff is located in southeastern Eagle County at 39°30′38″N 106°22′24″W / 39.51056°N 106.37333°W / 39.51056; -106.37333 (39.510570, -106.373458) at an elevation of 8,750 feet (2,670 m).
According to the United States Census Bureau, the town has a total area of 0.2 square miles (0.6 km), all of it land.
As of the census of 2000, there were 289 people, 109 households, and 68 families residing in the town. The population density was 1,256.4 people per square mile (485.1/km²). There were 122 housing units at an average density of 530.4 per square mile (204.8/km²). The racial makeup of the town was 62.98% White, 0.69% African American, 0.69% Native American, 0.35% Pacific Islander, 32.87% from other races, and 2.42% from two or more races. Hispanic or Latino of any race were 61.94% of the population.
There were 109 households out of which 26.6% had children under the age of 18 living with them, 49.5% were married couples living together, 9.2% had a female householder with no husband present, and 36.7% were non-families. 22.9% of all households were made up of individuals and 4.6% had someone living alone who was 65 years of age or older. The average household size was 2.65 and the average family size was 3.16.
In the town, the population was spread out with 20.8% under the age of 18, 13.8% from 18 to 24, 36.7% from 25 to 44, 18.7% from 45 to 64, and 10.0% who were 65 years of age or older. The median age was 33 years. For every 100 females, there were 124.0 males. For every 100 females age 18 and over, there were 126.7 males.
The median income for a household in the town was $50,104, and the median income for a family was $44,219. Males had a median income of $35,694 versus $30,750 for females. The per capita income for the town was $19,864. About 6.8% of families and 9.8% of the population were below the poverty line, including 8.5% of those under the age of eighteen and 31.6% of those sixty five or over.