The median income of Marathon County residents was an inflation-adjusted $29,692 per year. Marathon County had 54,820 households in 2017, with a population of 135,293.
The county with the highest median resident income in the state was Waukesha County. Waukesha County's median income was $38,295 per year after adjusting for inflation – $8,603 more than Marathon County. It had 156,996 households in 2017 and a population of 396,731.
Menominee County had the lowest annual resident income among counties in Wisconsin, with a median income of only $21,854 per year. That was $7,838 less than the median income in Marathon County at the time. Menominee County had 1,354 households in 2017 and a population of 4,506.
The table below shows the state's counties ranked by median annual resident earnings in 2017.