Pine River is a town in Lincoln County, Wisconsin. The population was 1,869 at the time of the 2010 census. The town of Pine River occupies the southeast corner of Lincoln County. It is bordered to the east by Langlade County and to the south by Marathon County. Part of the town's western border is with the city of Merrill, the Lincoln county seat. The remaind…Pine River is a town in Lincoln County, Wisconsin. The population was 1,869 at the time of the 2010 census. The town of Pine River occupies the southeast corner of Lincoln County. It is bordered to the east by Langlade County and to the south by Marathon County. Part of the town's western border is with the city of Merrill, the Lincoln county seat. The remainder of the western border follows the Wisconsin River.