Sour Lake is a city in Hardin County, Texas, in the southeastern part of the state within the Beaumont–Port Arthur metropolitan area. Its 2020 population was 1,773. The community's story moves through two distinct eras — mineral springs and oil — both of which shaped its identity. The town began as Sour Lake Springs, named for the sulphurous spring water that flowed into a nearby lake. In the late nineteenth century, the reputed healing properties of those springs drew visitors, and Sour Lake developed as a mineral-springs health resort, with grand hotels and bathhouses serving travelers seeking the waters. By 1885 the town already had two general stores, two hotels, and about 150 residents. That resort era ended abruptly with the Southeast Texas oil boom. After the famous 1901 gusher at nearby Spindletop, drillers turned their attention to Sour Lake, recognizing that the sulphur in the area signaled the presence of crude oil. A 1903 oil discovery at Sour Lake proved consequential: it helped turn the Texas Company — the firm founded by Joseph Cullinan — into Texaco, one of the world's major oil companies. The oil fields doomed the grand hotels and mineral baths, replacing them with a working oil town. Today Sour Lake is a small city whose economy and character reflect its petroleum heritage and its position in the Beaumont–Port Arthur region. Homes, schools, churches, and local businesses serve the community, and the area's museums and historical sites preserve the memory of both the springs and the oil boom. The town remains a quiet Southeast Texas community, connected by road to Beaumont's employment and services while retaining its own distinct history. Its dual legacy — healing springs and oil wealth — remains its defining story.