There are 8 US Post Offices in Olmsted County serving a total of 126,870 residents equating to 15,859 residents per post office. It's estimated that approximately 202,499 packages are handled across the 8 county post offices annually. Olmsted County is a county located in the U.S. state of Minnesota. As of the 2010 census, the population was 144,248. Its county seat and largest city is Rochester. The county was founded in 1855 and named for David Olmsted, a member of the first territorial council and the first mayor of St. Paul. Olmsted County is part of the Rochester, MN Metropolitan Statistical Area."