M-70 was a state trunkline highway in the US state of Michigan. In the 1920s, the highway originally connected Sterling in southwest Arenac County with Prescott in southeast Ogemaw County. The route was later adjusted to run from M-76 near Sterling along a convoluted route through Maple Ridge and Prescott to end at M-55 in Nester's Corners. The highway was still a gravel road when the designation was removed by 1960.