Silver City is a city in Mills County, Iowa, United States. The population was 245 at the 2020 census. The Wabash Trace—a railroad convert…Silver City is a city in Mills County, Iowa, United States. The population was 245 at the 2020 census. The Wabash Trace—a railroad converted to a bicycle trail—passes through here. At trailside, there is a small park with a gazebo, and across from it, a small cafe.