Michigan's M-3, Gratiot Highway-- Part 1

From Wikipedia.

Michigan's M-3 is a north-south trunkline highway running 43 miles long in the Detroit Metro Area.  For most of its length, it is known as the Gratiot Highway.  It starts in downtown Detroit and runs northward along one of the city's five main avenues.  Along the way, it passes several historic landmarks and a historic district.

It is one of the original avenues laid out by Judge Augustus Woodward after the Detroit Fire of 1805.  Later, it became a supply road to Fort Gratiot in Port Huron.

It was included in the State Trunkline System of 1913 and was signposted in 1919.  After that, it was a part of US-25 before being replaced by I-94 in 1960.  It received its M-3 designation in 1973.

--Brock-Perry