  pine river township is a civil township of gratiot county in the u.s. state of michigan. the population was 2,451 at the 2000 census. ==communities== *the city of alma is at the south side of the township, but is administratively autonomous. *the city of st. louis is at the southeast corner of the township, but is administratively autonomous. *forest hill is an unincorporated community in the township at . it was first platted in 1857, four miles from its current site, then moved to its present site when a major road was built in the area. forest hill had its own post office until 1957.walter romig, michigan place names, p. 203 ==geography== according to the united states census bureau, the township has a tot
Townships_in_Gratiot_County,_Michigan Townships_in_Michigan