Complex sentence: Lakeshore Drive around the island is shown on maps as early as 1915, and the M-185 designation was first assigned to Lakeshore Drive around Mackinac Island before 1936.
Split into simpler sentences: Lakeshore Drive around the island is shown on maps as early as 1915. The M-185 designation was first assigned to Lakeshore Drive around Mackinac Island before 1936.