Michigan State Route 66 runs in the northwestern portion of the county. It runs from the St. Joseph/Branch County Line, southwest of Athens, to the Branch/Calhoun County Line, south of Athens. MI St Rt 66 does not pass through any towns in Branch County. MI St Rt 66 is multi-plexed in Branch County. Michigan State Route 60, near Sherwood.
MI St Rt 66 intersects the following highways in Branch County. Michigan State Route 60, near Sherwood.
SB MI St Rt 66 at the Branch/Calhoun County Line. SB MI St Rt 66 north of east MI St Rt 60. SB MI St Rt 66 at east MI St Rt 66.
