In the mid-1980s, rising water levels in Lake Huron endangered M-185 and bicyclists. The roadway was overwashed by waves from the lake during a storm on May 31, 1985; the waves littered the road with gravel and dirt and raised fears of erosion. MDOT spent around $50,000 (equivalent to $ in ) to install of rock and filter cloth designed to prevent erosion. The expectation at the time was that Lake Huron could rise another that summer. Such a lake level increase prompted worries that the waves would wash away sections of the road. The lake had already washed away shoreline near Arch Rock; there was at least of berm between the road and shoreline in the 1970s and by 1985 some sections had been reduced to just . Storms later that year washed away sections of M-185, removing huge chunks of asphalt. MDOT closed those stretches on July 7, 1986, after the Independence Day weekend, to fix the damage. Repairs were budgeted to replace the missing sections of roadway at a cost of $894,366 (equivalent to $ in ); tourists were detoured inland, and uphill, to access the island's various tourist attractions.