Well it looks like the City of Marshall has permanently closed a portion of C Drive North which is part of the Great Lake-to-Lake Trail Route 1 between Marshall and Ceresco to the west. Marshall closed, abandoned, and then gave the road to Ford Motor Company for their new battery plant. You can read the story here.
There were precious few good ways into Marshall from the east, and now there is one less. The Route 1 map has been changed to show the new section in pink. You can see it here.
Heading East - Continue south through Ceresco, at C Drive North continue 1.2 miles on 12 Mile Rd. Turn left (east) onto A Drive North and continue 5.1 miles to Kalamazoo Ave aka Hwy 227. Turn left (north) onto Kalamazoo Ave and continue 0.5 miles to W. Spruce St. Turn right (east) onto W. Spruce St. and continue for 0.2 miles to Monroe St. Turn right (SE). You are now back on the Great Lake-to-Lake Trail Route 1.
Heading West - Continue northwest on Monroe St. to W. Spruce St. Turn left (west) onto W. Spruce St for 0.2 miles to Kalamazoo Ave aka Hwy 227. Turn left (south) onto Kalamazoo Ave and continue for 0.5 miles to A Drive North. Turn right (west) onto A Drive North and continue for 5.1 miles to 12 Mile Rd. Turn right (north) onto 12 Mile Rd and continue for 1.2 miles to C Drive North. Continue straight. You are now back on the Great Lake-to-Lake Trail Route 1.