The Wikipedia page for Chesaning, Michigan says that:
The first mention of Chesaning in the written pages of history is the Saginaw Treaty, signed in 1819. This treaty was between members of the Saginaw Tribe, Chippewa Indians and the government of the United States. They established a number of reservations, including 10,000 acres (40 km2) along the banks of the Shiawassee River known as “Big Rock Reserve.” Chesaning is a Chippewa word meaning “big rock place”. The treaty continued in effect until 1837 when a second treaty led to the reserve being surveyed and offered for sale in 1841. The first land was sold at $5 per acre to brothers Wellington and George W. Chapman, and Rufus Mason. After making their land purchase, they traveled back to Massachusetts and moved their families to their new wilderness home by late summer of 1842.
During the months they had been away from their land, several settlers had moved into the area, building a dam and a sawmill. A few years later, a grinding mill was added. The new settlers named their community “Northampton” in honor of the home they had left in Massachusetts. In 1853, the legislature changed the name to Chesaning, the traditional name for the village and township. The first township elections, held in 1847, are considered to be the official birthday of the community.
They explain that The rock was one of the features of the area since Chesaning was settled. Located in woods to the east of Chesaning, the large rock inspired the name of the area. See it bigger at Seeking Michigan and check out more funny photos on Michigan in Pictures.