Dunes City is a city in Lane County, Oregon, United States. The population was 1,303 at the 2010 census. According to the United States Censu…Dunes City is a city in Lane County, Oregon, United States. The population was 1,303 at the 2010 census. According to the United States Census Bureau, the city has a total area of 3.47 square miles, of which, 2.70 square miles is land and 0.77 square miles is water.