Michigan State Route 51 runs north-south through southeastern Berrien County. This connects Niles to South Bend, IN, via IN St Rt 933. MI St Rt 51 passes through the following town in Berrien County. Niles
MI St Rt 51 is multi-plexed in Berrien County. BUSN. U.S. Rt. 12, at Niles.
MI St Rt 51 intersects the following highways in Berrien County. Michigan State Route 140, near Niles. BUSN. U.S. Rt. 12, at Niles.
NB MI St Rt 51 north of Niles. Junction marker on EB former BUSN. U.S. Rt. 12 in Niles. A junction marker on EB Main Street. NB MI St Rt 51 south of BUSN MI St Rt 60. A BGS on EB Main Street. NB MI St Rt 51 near Silverbrook Ave. NB MI St Rt 51 at U.S. Rt. 12. EB BUSN. U.S. Rt. 12/SB MI St. Rt. 51 at U.S. Rt. 12 on the southside of Niles. A guide marker on the ramp from NB U.S. Rt. 31. A BGS on EB U.S. Rt. 12. A BGS on EB U.S. Rt. 12. A BGS on WB U.S. Rt. 12. A BGS on WB U.S. Rt. 12. A BGS on WB U.S. Rt. 12. SB MI St Rt 51 south of U.S. Rt. 12. SB MI St Rt 51 south of U.S. Rt. 12. A guide marker on SB MI St Rt 51 south of Niles. SB MI St Rt 51 south of Niles.
