Best SEO and internet marketing services in Putnam County NY. Putnam County zip codes - 10509, 10524, 10537, 10542, 12563 Putnam County is a county in the U. S. state of New York. It is located in the southeastern part of the New York State. The county was founded in 1812. The county’s seat is Carmel as well as the largest town. The county was named after Israel Putnam, an American army general officer and Freemason. The total area of a county is 246 sq mi (that is 637 sq km). Land is 230 sq mi (or 596 sq km), water is 16 sq mi (41 sq km) and water takes 6.5% of the whole territory. Population of the county is 99,710 residents, according to the census in 2010. The density is 433/sq mi (167/sq km). The county is located in Hudson River Valley. The Putman county is generally hilly. The highest point is Scofield Ridge, 1,540 feet (or 469 m) above sea level. There are several reservoirs in the county. They are: Bog Brook, Croton Falls Reservoir, Diverting Reservoir, East Branch, Middle Branch, West Branch and Boyds Corner Reservoir. The climate is humid continental. There are six public school districts. There you can visit: Chuang Yen Monastery, Clarence Fahnestock State Park, Donald J. Trump State Park, Thunder Ridge Ski Area, etc.