 M @-@ 18 is a north – south state trunkline highway in the Lower Peninsula of the US state of Michigan . It runs for 77 @.@ 530 miles ( 124 @.@ 772 km ) through the central region of the state connecting US Highway 10 ( US 10 ) near North Bradley with M @-@ 72 in rural Crawford County near the community of Luzerne . In between , the roadway connects several smaller communities while running through woodlands in both state and national forest areas . Two segments of M @-@ 18 run along sections of county boundaries , and one part of the highway forms a component of the business loop for the village of Roscommon . 
