Spearfish is located in Lawrence county South dakota with a geographic area of 16.8 square miles. The total population in Spearfish is 11,702 with 48.3% male and 51.7% female. Children under age 5 represent 5.3% of the population, under age 18 equal 17.2% of the population and over age 65 is 21.6% of the population. The median household income is $50,072, per capita income is $37,077. There are a total of 5,103 housing units with 51.2% owner occupied. Education includes 21.3% of residents that are high school graduates and 39.4% with a bachelor's degree or higher. The average temperature in Spearfish in the summer is 69 degrees, and in the winter 15 degrees.