There are 13 US Post Offices in Grant County serving a total of 28,030 residents equating to 2,156 residents per post office. It's estimated that approximately 44,739 packages are handled across the 13 county post offices annually. Grant County is a county located in the U.S. state of New Mexico. As of the 2010 census, the population was 29,514. Its county seat is Silver City. The county was founded in 1868 and named for Ulysses S. Grant, 18th President of the United States. Grant County comprises the Silver City, NM Micropolitan Statistical Area."