 At Woodport , Lake Hopatcong ends as Route 181 crosses the line from Morris County to Sussex County . Now in the town of Sparta , Route 181 becomes Woodport Road , winding northward back toward Route 15 . The two routes parallel northwestward and intersect with Blue Heron Drive , which connects the two roads . Once again , Route 181 turns northwest and away from Route 15 , reaching downtown Sparta . The two @-@ lane road winds northwest through the center of Sparta , reaching a junction with County Route 517 ( CR 517 ; Sparta Avenue ) , which connects to Route 15 once again . 
