Best SEO and internet marketing services in St. Lawrence County NY. St. Lawrence County zip codes - 12922, 12927, 12949, 12965, 12967, 12973, 13613, 13614, 13617, 13621, 13623, 13625, 13630, 13633, 13635, 13639, 13642, 13645, 13646, 13647, 13649, 13652, 13654, 13658, 13660, 13662, 13664, 13666, 13667, 13668, 13669, 13670, 13672, 13676, 13677, 13678, 13680, 13681, 13683, 13684, 13687, 13690, 13694, 13695, 13696, 13697, 13699 St. Lawrence County is a county in the U.S. state of New York. It is located in the north of New York State. The county was founded in 1802. It takes its name after Saint Lawrence River. Carton is county’s seat. The largest city is Ogdensburg. Total are of the county is 2,821 sq mi (7,306 sq km), where land is 2,680 sq mi (6,941 sq km) and water is 141 sq mi (365 sq km). There live 111,944 people, according to the census in 2010. Density is 42/sq mi (16/sq km). It is the largest county by area in New York. The strongest earthquake in New York State history took place in the county in 1944. There are such lakes and rivers: Cranberry Lake, Lake Ozonia, Oswegatchie River and part of the county is located in the Adirondack Park. There are 17 school districts in the county. St. Lawrence University, State University of New York at Potsdam, Clarkson University, the State University of New York at Canton and several others are situated there. There are such public use airports: Massena International Airport, Ogdensburg International Airport, Potsdam Municipal Airport and Moores Airport. Only one city is located in the county – Ogdensburg.