Harrison, SD has a population of 109 and is the 26,696th largest city in the United States. The population density is 1,011 per sq mi which is 8323% higher than the South Dakota average and 1016% higher than the national average. The median age in Harrison is 43 which is approximately 18% higher than the South Dakota average of 37. In Harrison, 68% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 61% of Harrison residents were born in South Dakota, 32% were born out of state, 6% were born outside of the United States and 0% were foreign born.