Best SEO and internet marketing services in Dutchess County NY. Dutchess County zip codes - 12501, 12504, 12506, 12507, 12508, 12510, 12511, 12512, 12514, 12522, 12524, 12527, 12537, 12538, 12540, 12545, 12564, 12569, 12570, 12571, 12572, 12574, 12578, 12580, 12581, 12585, 12590, 12592, 12594, 12601, 12602, 12603, 12604 Dutchess County is a county in the U.S state of New York. It is located in the south-east of New York State. The county was founded in 1713. It was named after Duchess of York. Its seat is Poughkeepsie as well as the largest city. Total area is 825 sq mi (or 2,137 sq km). Land is 796 sq mi (2,062 sq km) and water is 30 sq mi (78 sq km). Population of the county is 297,488 people, according to the census in 2010. Density is 374/sq mi (144/sq km). There are two cities in the county: Beacon and Poughkeepsie. It is mostly hilly and the Hudson Highlands are located in the southwest of the county and the Taconic Mountains are located in the northeast. Summit of Brace Mountain is the highest point in the county (2,311 feet (704 m) above sea level). Such national protected areas can be found in the county: Eleanor Roosevelt National Historic Site, Home of Franklin D. Roosevelt National Historic Site, and Vanderbilt Mansion National Historic Site. Such parks are there: Bowdoin County Park, Hudson Highlands State Park, Stratt Town Park, Wilcox County Park and Tymor Forest. Also there are three airports in the county.