County Origins
Midland County got its name from the railroad running halfway across Texas
Midland County was organized in 1885 and named for its location at the midpoint of the Texas and Pacific Railway between Fort Worth and El Paso.
The Texas and Pacific Railway reached this area in 1881, bringing early settlers. The county was carved out of Tom Green County in 1885. The city of Midland became the county seat. Before that, the land was open range used for sheep and cattle ranching.
The county sits on the Llano Estacado's southern edge at elevations between 2,550 and 2,900 feet. Annual rainfall averages only about 13 to 15 inches, making water a constant challenge. Early farmers and ranchers had to drill wells — and sometimes hit oil while looking for water.
Source to confirm: Handbook of Texas — Midland County