In 1917, the Upper Peninsula Development Bureau created a tourist route that is a predecessor of the modern Great Lakes Circle Tours (GLCT). The Great Lakes Automobile Route was a series of roads on both the Upper and Lower peninsulas of Michigan. It included US 31 between Manistee and the Benton Harbor–St. Joseph area. The concept did not last a year; the American entry into World War I and a lack of focus on a single route consigned the idea into obscurity. The idea of a tourist route around the Great Lakes was revived in 1986 as a pet project of Michigan First Lady Paula Blanchard. MDOT and its counterparts in Wisconsin, Minnesota and Ontario created the GLCT scheme which includes the LMCT that follows US 31 from Lake Michigan Beach northward to Manistee and from Traverse City north to the terminus near Mackinaw City excluding locations where business loops run closer to the lake at South Haven, Muskegon, Whitehall–Montague and Pentwater. A group of area residents initiated an effort to have the former West Michigan Pike designated what is now called a Pure Michigan Byway. The designation would prioritize the area for historic preservation grants. A Preserve America grant funded a survey from June 2007 through September 2010, the results of which were a set of reports through the Michigan State Historic Preservation Office on the historical nature of the West Michigan Pike. In 2011, the group was in the process of securing resolutions from municipalities along the highway in support of the designation. According to officials working on the byway, it can take up to seven years to complete the process. The initial proposals had the byway continuing to Mackinaw City, but as approved in 2016, it runs from New Buffalo on I-94 to Ludington, following US 31 except between business loops at South Haven, Muskegon, Whitehall–Montague and Pentwater. MDOT maintains a listing of the historic bridges in the state; along US 31, the department has listed four structures. In downtown Charlevoix, the US-31–Island Lake Outlet Bridge carries the highway over a channel dredged between Lake Michigan and Round Lake that also connects to Lake Charlevoix. Built from 1947 through 1949, it is the fifth bridge at the location. It is a double-leaf bascule bridge. In Petoskey, the highway crosses Bear Creek on a concrete girder bridge built in 1930. At in length, it is the fourth longest such bridge in Michigan. In Manistee, the Manistee River is spanned by a double-leaf bascule bridge built in 1933.