Pioneer rancher Joseph P. Gainer, known as Grandpa Gainer, settled 320 acres of land about three miles north of this site in 1858, and the highest point in the area on his land came to be called Mt. Gainer. A small farming and ranching community of the same name developed along the south fork of Onion Creek, and the name appeared on county maps by 1877, when a post office opened, though it closed two years later. In the early years of the twentieth century, the village included two general stores, a gristmill, a molasses mill, a Methodist congregation, and a Baptist church established in 1907. Area settlers secured a one-room schoolhouse in 1906 on land donated by resident Charlie Seal, and in 1908 a farmer's union formed to encourage further development while also playing an important part in community social life, with the school serving as a place for worship, education, and gatherings. A two-room school built in 1921 soon expanded, and a staff of three taught local children until 1944, when the Mt. Gainer School District was consolidated with Dripping Springs schools. By 1998, only the school cistern and steps, a teacherage, native rock fences, and a few buildings on private land remained of the once thriving village.