In the 2010 census, there were 18,065 residents living in Hill City. Most of these individuals identify themselves as white. One-third of all Americans do not identify their ancestry. In addition to this, one-fifth of adult citizens identified as Hispanic or Latino. The remaining two percent of residents identified as being of some other race. According to the census, people living in Hill City report having ancestry from a wide variety of countries, with German and Norwegian the most common. In South Dakota, the percentage of veterans is higher at 9.1%.
The median income in Hill City is $71,417. This is a higher income than the national average. The median household income is $54,464. A family with two children has an income of $70,417. In the city, there are 666 white residents and 161 Hispanic residents. The median age of residents is thirty-five years old. A total of seventy-two percent of the population lives in poverty.
The first post office in Hill City was established on November 26, 1877. The city almost ceased to exist after miners moved to the northern part of the Black Hills, which is located to the north of Hill City. The town's population has steadily increased since then. The town is home to one of the oldest schools in the state and is home to several historic buildings. In addition to the Harney Peak Hotel, the city is home to the Black Hills Institute of Geological Research (BHIR). This institute is involved in dinosaur fossil excavation and display. This company had a legal dispute with Sue, a local resident.