Gladstone is a city in Delta County in the U.S. state of Michigan. It is also known locally as "Happy Rock", a play on words of Gladstone. First settled in 1877, Gladstone's original name was Minnewasca. The population was 4,973 at the 2010 census.U.S. Highways 2 and 41 run concurrently through the city, connecting with Escanaba, nine miles to the south. US 41 runs north to Marquette and US 2 runs east to Manistique. M-35 runs northwest 52 miles to Gwinn and merges with US 2/US 41 south to Escanaba.