Midland County is on the southern edge of the High Plains in West Texas, bounded on the east by Glasscock County, on the south by Upton County, on the West by Ector County, and on the north by Martin and Andrews counties. The center of the county lies at approximately 31°52' north latitude and 102°00' west longitude, 120 miles south of Lubbock. The county was named for its location halfway between Fort Worth and El Paso on the Texas and Pacific Railway. Midland County extends across 939 square miles of flat land broken by draws and covered by scattered mesquite; sandy red and dark loam soils predominate, and elevations range from 2,550 to 2,900 feet above sea level. There are no rivers or any other permanent surface waters in the county. Annual rainfall is only 13.51 inches. Temperatures range from an average minimum of 31° F in January to an average maximum of 95° F in July; the growing season lasts 218 days. In the 1980s the agricultural sector of county's economy averaged $11 million in annual income from beef cattle, hogs, sheep, cotton, sorghums, and small grains. Over 13,600 acres are irrigated. The city of Midland is the county's seat of government and the bustling administrative center of the huge Permian Basin petroleum fields. Over $1 billion was paid in wages to the county's 54,207 workers in 1980. About $53,800,000 in goods were manufactured in Midland County in 1982, including clothing, oilfield equipment, plastics, electronic calculators, and watches. County wells produced 7,616,000 barrels of oil, valued at over $225 million, that year. Interstate Highway 20 cuts the northeast corner of the county, coursing southwesterly, and State Highway 349 bisects it north to south. The Missouri Pacific Railroad crosses the northwest corner of the county, connecting the city of Midland with Odessa, Abilene, and other points to the northeast and southwest.
In 1953 archaeologists discovered the fossilized remains of "Midland Minnie" on the Scharbauer Ranch in the county. Though "Minnie's" age could not be conclusively established, the remains were tentatively determined to belong to the Folsom culture of the late Pleistocene age, when the area had a cool, humid climate. Fossil evidence of extinct species of horse, antelope, peccary, wolf, mammoth, and sloth were also found at the site. Long before settlers entered what is now Midland County, the region was crossed by a number of early transportation routes. The Comanches used the Great Comanche War Trail, which ran through the area from Indian territory to the south. In 1839 Mexican travelers blazed the Chihuahua Trail, which ran northwesterly from the site of Big Spring to Castle Gap and Horsehead Crossing on the Pecos River. Another trail was the Emigrant Road, which led to the site of Preston on the Red River. Wagon roads also crossed through the area. One led from the head of the North Concho to the Double Mountain Fork of the Brazos; another, also beginning at the head of the North Concho, ran to Five Wells and Laguna Cuates. There were also two wagon roads that led from Five Wells to Monument Spring in New Mexico. After 1850 these two roads were familiar to various surveying parties charged with marking out the Texas-United States boundary lines. In the 1870s buffalo hunters decimated the great herds occupying the region, forcing Indian migration and setting the stage for a new era of land use. The last recorded incident of White-Indian strife in what is now Midland County occurred in 1879. Twenty-five Comanches led by Chief Black Horse were given permission to leave their reservation to hunt buffalo. After the Indians resorted to eating horses from local ranches when no buffalo could be found, they were attacked by Texas Rangers, who surprised them while they were eating one of the stolen horses.
Ranching began in the area after Herman Garrett shipped sheep from California to El Paso on the Southern Pacific Railroad. Garrett drove 300 sheep across the Pecos River, at the present site of the town of Midland, before moving on to Mustang Draw and settling in as the county's first permanent settler. Promotions by the Texas and Pacific Railway, which built into the area in 1881, brought other sheepmen to what is now Midland County. Nelson Morris, a Chicago meatpacker who bought 200,000 acres from the state for his Black Angus ranch, was the first to fence county land. Cattle were introduced after ranchers discovered that abundant water could be obtained from wells. In 1885, when 300 people were living in the area, the Texas state legislature established Midland County from lands previously assigned to Tom Green County, and the county was organized later that same year. The town of Midland, originally named Midway to suggest its place on the Fort Worth-El Paso rail line, became county seat. The Staked Plains, the county's first newspaper, began publication in 1885, and another paper, the Midland Gazette, was in circulation by 1889; the county's first school house was built the next year. By 1890 twenty-nine ranches had been established in the county, and the agricultural census reported 14,867 cattle and 13,364 sheep in the area. No crops were reported in the county that year, though some early settlers did grow limited amounts of corn and grain, sometimes using irrigation. The United States Census counted 1,033 people living in Midland County in 1890. The area had good soils but only sparse rainfall, and in 1891 the United States Department of Agriculture conducted a rain-making experiment in the county; watermelons and pumpkins were planted in another experiment. Further settlement in the area was encouraged when the Texas legislature passed the Four-Section Act of 1895; this law enabled stockmen to buy four sections for each family member at favorable terms, and provided opportunities for leasing range lands for a modest price. By 1900 there were seventy-three ranches in Midland County, and cattle dominated the local economy. Almost 45,000 cattle were reported in the area that year, while the number of sheep had declined to only 2,257. Only one acre of cropland was reported in the county that year; it was planted in oats.
Farmers moved into Midland County in increasing numbers between 1900 and 1930, though ranching continued to dominate the local economy until the oil boom of the 1920s. By 1910 there were 178 ranches and farms in Midland County. While 29,000 cattle were reported on local farms that year, crop farming was beginning to become established: 2,438 acres of sorghum, 1,755 acres of cotton, and 421 acres of corn were grown in the county that year. Some sectors of the county's economy contracted during the droughts of the late 1910s; by 1920 the number of farms and ranches in the county had declined to 133. Midland College, established in the city of Midland by the Christian Church in 1910 as a junior college, failed in 1921. That same year the Midland and Northwestern Railway ceased service; it had operated as a short line serving farmers and cattlemen near the towns of Midland, Fasken, and Florey since 1917. Cotton cultivation continued to expand across county lands, however, as irrigation projects after 1911 showed farmers and ranchers how to increase production. By 1920 over 4,600 acres in Midland County were devoted to cotton, and 2,449 people were living in the area. Cotton farming continued to expand in the county during the 1920s. By 1930 more than 31,200 acres in the county were planted in cotton, and there were 361 farms and ranches in the area. Midland County's economy also benefitted when oil was discovered in neighboring counties. After strikes were made in Reagan County in 1923 and in Ector County in 1926, the city of Midland became the corporate headquarters for oil companies. Farm expansion and the oil boom combined to attract thousands of new people to the county, and by 1930 the area's population had increased to 8,005. The oil boom also helped to buoy the area economy during the Great Depression of the 1930s. Cotton production dropped by more than 60 percent during the 1930s, and by 1940 only 9,622 acres in the county were devoted to the fiber; during that same period, however, the population of the county increased to 11,721. A great boom in 1945 resulted from production of Midland County wells, and the Midland South Pool success in 1947 established the wealth of the Permian Basin. Yet another boom followed between 1949 and 1952, assuring long-range prosperity for the county; the town of Midland came to be called "The Tall City of the Plains," as oil companies built high-rise buildings there. The county became one of the more productive petroleum areas in the state. Almost 17,060,000 barrels of crude were produced in Midland County in 1956, 11,747,000 barrels in 1965, 11,274,000 barrels in 1974, and more than 7,615,000 barrels in 1982. In 1990 the county produced 8,693,000 barrels of crude oil; by January 1, 1991, 455,926,000 barrels of oil had been taken from county lands since discovery in 1945.
The voters of Midland County supported Democratic candidates in every presidential election between 1888 and 1948. The county's loyalties shifted in 1952, however, when a majority of voters supported Dwight D. Eisenhower, the Republican candidate, over Democrat Adlai Stevenson. Midland County supported Republican candidates in every presidential contest between 1952 and 1992. In 1982 90 percent of the land in the county was in farms and ranches, and 9 percent of the land was cultivated; about 24 percent of the population worked in agriculture. Local farmers grew cotton, hay, wheat, sorghum, pecans, and watermelons; the primary livestock were cattle, sheep, and hogs. Much of the area's economy revolved around oil and gas extraction and related industries, though many workers were employed in construction, trucking, the production of plastics, and other industries; the county's non-farm income in 1981 reached $1,452,334,000. Except for a slight dip in the 1960s Midland County's population has grown steadily since the boom of the 1940s, when the population more than doubled. The United States Census counted 25,785 people living in the county in 1950, 67,717 in 1960, 65,433 in 1970, and 82,636 in 1980. By 2014 there were 155,830 people living in Midland County. About 50 percent were Anglo, 6.8 percent African American, and 41.1 percent Hispanic. Most of the area's population lives in the city of Midland (population, 127,598). Other communities include Odessa (mostly in Ector County), Germania, and Spraberry. Midland is also the location of the Permian Basin Petroleum Museum, the Museum of the Southwest, the Midland County Historical Museum, and the Pliska Aeroplane Museum.