Mich. Comp. Laws § 250.1014: "Pere Marquette Memorial Highway."

Sec. 14.

The part of highway US-31 beginning at the county line of Muskegon and Oceana Counties and extending north to the county line of Mason and Manistee Counties, excluding the portion of highway US-31 in Oceana County beginning at the W. Shelby Road exit 144 and continuing north to the Hart Polk Road exit 149, shall be known as the "Pere Marquette Memorial Highway".