Town Hall Address 321 Greenwich St. Stewartsville, NJ 08886 United States- Warren County Website https://www.greenwichtwp.com/ County Clerk 908-859-0909 Ext. 10 321 Greenwich St. Stewartsville, NJ 08886 United States Assessor 908-859-0909 Ext. 13 Tuesday: 3:00 P.M. - 5:00 P.M. 321 Greenwich St. Stewartsville, NJ 08886 United States Tax Collector 908-859-0909 Ext. 2910 Monday: 4:30 P.M. - 6:30 P.M. 321 Greenwich St. Stewartsville, NJ 08886 United States Attorney 908-852-2600 321 Greenwich St. Stewartsville, NJ 08886 United States Mayor 908-859-0909 321 Greenwich St. Stewartsville, NJ 08886 United States Municipal Court 908-454-6121 50 Municipal Dr. Phillipsburg, NJ 08865 United States County Warren