Natural features have often played a role in the naming of communities. One such settlement was Big Rock. Named after a massive boulder, this hamlet was located at the crossroads of present-day M-32 and Thornton Road. Seth Gillet became the first postmaster in 1882. By 1902 a general store owned by Briley Township pioneer William Remington housed the post office. At that time a church and school, a grange hall, a sawmill and a blacksmith shop were also located in Big Rock. The post office closed in 1920.