where is hopatcong nj
Hopatcong, NJ. Sponsored Topics. Hopatcong is a Borough in Sussex County, New Jersey, United States. As of the United States 2000 Census, the borough population was 15,888. The area had been called Brookland in the 19th century and the lake that was expanded to become Lake Hopatcong had been known as Great Pond or Brookland Pond.