As of the census of 2010, there were 1,182 people, 532 households, and 326 families living in the town. The population density was. There were 606 housing units at an average density of. The racial makeup of the town was 97.8% White, 0.2% African American, 0.8% Native American, 0.4% from other races, and 0.8% from two or more races. Hispanic or Latino of any race were 1.2% of the population. There were 532 households of which 25.0% had children under the age of 18 living with them, 51.5% were married couples living together, 8.3% had a female householder with no husband present, 1.5% had a male householder with no wife present, and 38.7% were non-families. 33.5% of all households were made up of individuals and 16.6% had someone living alone who was 65 years of age or older. The average household size was 2.16 and the average family size was 2.76. The median age in the town was 47.5 years. 19.3% of residents were under the age of 18; 6.1% were between the ages of 18 and 24; 19.5% were from 25 to 44; 31% were from 45 to 64; and 24% were 65 years of age or older. The gender makeup of the town was 49.1% male and 50.9% female.
2000 census
As of the census of 2000, there were 1,161 people, 476 households, and 318 families living in the town. The population density was 582.2 people per square mile. There were 545 housing units at an average density of 273.3 per square mile. The racial makeup of the town was 96.64% White, 1.64% Native American, 0.17% Asian, 0.17% from other races, and 1.38% from two or more races. Hispanic or Latino of any race were 0.60% of the population. There were 476 households out of which 27.7% had children under the age of 18 living with them, 59.0% were married couples living together, 6.1% had a female householder with no husband present, and 33.0% were non-families. 29.4% of all households were made up of individuals and 14.3% had someone living alone who was 65 years of age or older. The average household size was 2.34 and the average family size was 2.91. In the town, the population was spread out with 24.1% under the age of 18, 5.8% from 18 to 24, 24.7% from 25 to 44, 24.3% from 45 to 64, and 21.1% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 95.1 males. For every 100 females age 18 and over, there were 87.4 males. The median income for a household in the town was $41,029, and the median income for a family was $50,598. Males had a median income of $33,750 versus $21,000 for females. The per capita income for the town was $18,300. About 3.2% of families and 6.4% of the population were below the poverty line, including 4.8% of those under age 18 and 13.5% of those age 65 or over.
Public education in the town of Sundance is provided by Crook County School District #1. Zoned campuses include Sundance Elementary School, and Sundance Secondary School. Sundance has a public library, a branch of the Crook County Public Library System.
After his release from the town jail in 1888, Harry Longabaugh, an outlaw and member of Butch Cassidy's Wild Bunch in the American Old West, acquired the moniker, "the Sundance Kid". His nickname entered the popular culture with release of the 1969 movieButch Cassidy and the Sundance Kid, which won several Academy Awards, including Best Original Screenplay. Robert Redford, who portrayed Longabaugh in the movie, later named his Sundance Ski Resort near Provo, Utah, and the Sundance Film Festival after this character. The town of Sundance is the primary setting of Scumble, a children's novel by Ingrid Law, and a sequel to her earlier children's book, Savvy. Sundance, Wyoming is also the primary setting for Lorelei James' novels in her "Rough Riders" series of 16 books involving the fictional McKay family, eking out a living as multi generational ranchers and the younger generation's accepting who they are individually, the ins and outs of working with family every day and finding love.
