Town Hall Address 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States- Sussex County Website http://www.hopatcong.org County Clerk 973-770-1200 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States County Admin 973-770-1200 Ext. 4 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States Assessor 973-770-1200 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States Tax Collector 973-770-1200 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States Attorney 973-729-2117 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States Mayor 973-770-1200 111 River Styx Rd. Hopatcong, NJ 07843-1599 United States Municipal Court 973-770-1200 111 River Styx Rd. Hopatcong, NJ 07843 United States County Sussex