Town Hall Address 100 Belvidere Ave. Washington, NJ 07882-1426 United States- Warren County Website http://www.washingtonboro-nj.gov County Clerk 908-689-3600 Ext. 127 100 Belvidere Ave. Washington, NJ 07882-1426 United States Assessor 908-689-3600 Ext. 129 Monday: 5:00 P.M. - 7:00 P.M. 100 Belvidere Ave. Washington, NJ 07882-1426 United States Tax Collector 908-689-3600 Ext. 116 100 Belvidere Ave. Washington, NJ 07882-1426 United States Attorney 908-735-5161 100 Belvidere Ave. Washington, NJ 07882-1426 United States Mayor 908-689-3600 100 Belvidere Ave. Washington, NJ 07882-1426 United States Municipal Court 908-689-7066 100 Port Murray Rd. Port Murray, NJ 07865 United States County Warren