Key, TexasKey is an unincorporated community in Dawson County, Texas, United States. According to the Handbook of Texas, the community had an estimated population of 20 in 2000.GeographyKey is located at the intersection of U.S. [Route 180 in Texas|U.S. Highway 180] and Farm to [Market Road 178], east of Lamesa, northwest of Big Spring, and west of Snyder in east-central Dawson County.EducationKey had its own school in 1947. Today, Key is served by the Lamesa [Independent School District].