Letcher, SD has a population of 208 and is the 24,273rd largest city in the United States. The population density is 338 per sq mi which is 3025% higher than the South Dakota average and 273% higher than the national average. The median age in Letcher is 36 which is approximately 2% lower than the South Dakota average of 37. In Letcher, 49% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 74% of Letcher residents were born in South Dakota, 23% were born out of state, 0% were born outside of the United States and 2% were foreign born.