The median income of Dewey County residents was an inflation-adjusted $23,533 per year. Dewey County had 1,648 households in 2017, with a population of 5,709.
The county with the highest median resident income in the state was Lincoln County. Lincoln County's median income was $37,691 per year after adjusting for inflation – $14,158 more than Dewey County. It had 18,736 households in 2017 and a population of 53,147.
Oglala Lakota County had the lowest annual resident income among counties in South Dakota, with a median income of only $12,372 per year. That was $11,161 less than the median income in Dewey County at the time. Oglala Lakota County had 2,920 households in 2017 and a population of 14,291.
The table below shows the state's counties ranked by median annual resident earnings in 2017.