 This would have created two discontinuous segments of M-29, so the section designated as such from Bay City to Port Austin was renumbered to M-25.In 1939, M-29, which formerly terminated at US 25 and Gratiot Avenue was shifted slightly eastward and realigned to run along Jefferson Avenue along the Lake St. Clair shoreline.It continued along Jefferson Avenue down to Grosse Pointe Shores where it then turned west along Vernier Road where it then terminated at US 25 on the Detroit – East Detroit border.