Coke County (F-12), in West Central Texas, is bounded on the east by Runnels County, on the south by Tom Green County, on the west by Sterling County, and on the north by Mitchell and Nolan counties. It was named for Richard Coke, a Texas governor. The county center is at 31°54' north latitude and 100°33' west longitude, about thirty miles north of San Angelo. The terrain includes prairie, hills, and the Colorado River valley; sandy loam and red soils predominate. The elevation varies from 1,800 feet in the south to 2,600 feet in the north, where Nipple Mountain, Meadow Mountain, Horse Mountain, and Hayrick Mountain are located. Its 911-square-mile area is drained by the north branch of the Colorado River and Yellow Wolf Creek. Native grasses include mesquite grass, needlegrass, sideoats, bunchgrass, and crabgrass. Ninety percent of Coke County's agricultural income of $10 million comes from cattle, sheep, goats, and horses. The rest is from cotton, sorghum, small grains, hay, fruits, and peanuts. Coke County is among the leading counties in sheep ranching. Extraction of sand and gravel is a minor industry, though the county has no manufacturing; county oil production of 2,249,804 barrels in 1982 earned almost $77 million. The annual rainfall is 20.48 inches. The average minimum temperature in January is 29° F; the maximum in July is 97°. The growing season lasts 226 days.
From about 1700 to the 1870s, Comanche Indians ranged the area that is now Coke County. They competed with the Tonkawa Indians to the east and the Lipans to the west for dominance of the Edwards Plateau and Colorado River valley. In 1851 Fort Chadbourne, in the northeast part of the future county, was established by the United States Army to protect the frontier; the fort was manned until the Civil War. The Butterfield Overland Mail ran through the area from 1858 to 1861.
Between 1860 and the early 1880s the only settlers in what became Coke County were ranchers attracted to open grazing land. J. J. Austin established his ranch headquarters near Sanco in 1875, and Pate Francher settled in the area in 1877, after he drove a cattle herd for John Austin and Joe McConnel to the Odom Ranch near Sanco. In 1882 the Texas and Pacific Railway began providing service to San Angelo, and settlers started coming into the region in somewhat larger numbers. Severe drought in the 1880s led to fence cutting and its attendant quarreling, particularly on L. B. Harris's ranch: when landless cattlemen found that Harris had fenced in waterholes on the range, they destroyed $6,000 worth of his posts and wire. State authorities eventually settled the disputes.
The Texas legislature established Coke County in 1889, carving it out of territory previously assigned to Tom Green County; the county was organized that same year, with Hayrick as county seat. In 1889 the county's first newspaper, the Hayrick Democrat, began publication; shortly thereafter it was renamed the Rustler. By 1890 there were 163 farms and ranches in the county, and 2,059 people lived there. Only about 4,000 acres of the county was classified by the census as "improved" at this time. Ranching dominated the local economy, and 13,806 cattle were counted in Coke County that year.
In 1891, after an election, the new town of Robert Lee became the county seat; Robert E. Lee had once served at Fort Chadbourne. That same year, the county's newspaper moved to the new county seat and was renamed the Robert Lee Observer. Early settlers named a new town Bronte, after English writer Charlotte Brontë; another was named Tennyson, in honor of the English laureate. By 1900, 480 farms and ranches had been established in the county, encompassing 605,842 acres. That year more than 46,000 cattle and about 17,500 sheep were counted in Coke County. Farming had also grown, for about 4,200 acres were planted in corn and almost 7,000 acres were devoted to cotton.
In 1907, when the Kansas City, Mexico and Orient Railway built tracks north out of San Angelo, the little towns of Tennyson, Bronte, and Fort Chadbourne lay near the line, and residents moved their business centers to enjoy the benefits of transportation. The county seat, Robert Lee, was not on the tracks, but managed to survive nonetheless.
In the first years of the twentieth century cotton culture expanded significantly. By 1910 cotton was planted on more than 29,600 acres in Coke County; by 1920 cotton acreage had declined only slightly, to about 28,200 acres. Cotton production plunged sharply during the 1920s, however, apparently because of a boll weevil infestation, and by 1929 county farmers planted only 5,321 acres with cotton. These fluctuations in cotton production seem related to changes in the county's population that took place at about the same time. In 1910, near the height of the cotton boom in the county, 969 farms and ranches had been established in the county, and the population had grown since 1900 to 6,412. By 1920, after cotton production had begun to decline, there were only 721 farms and ranches in the area, and the county's population had dropped to 4,557. By 1925, as cotton production continued to drop, the number of farms had declined to 636.
But farmers were expanding their production of corn, wheat, and sorghum; in 1929 they harvested more than 55,300 acres of cropland in the county. Thousands of fruit trees were also planted during this time, and by 1920 about 18,000 fruit trees, including almost 14,000 peach trees, were growing in Coke County. Meanwhile, cattle ranching remained an important part of the economy. Though the number of cattle declined during the 1910s, by 1929 almost 31,000 cattle were grazing in the county. The number of farms and ranches in the county increased from 636 to 838 between 1925 and 1929. Meanwhile, the population of the county also began to recover; by 1930 there were 5,253 people living in the county.
The momentum of this recovery was lost during the Great Depression of the 1930s. Cropland harvested in Coke County dropped more than 10 percent between 1930 and 1940, and the number of farms in the area fell again to 756. Hundreds of people left during the depression, and by 1940 only 4,593 remained.
Prospects for the local economy were greatly improved after 1942, however, when oil was discovered in the county. In November and December 1946, Sun Oil drilled the discovery well in the Jameson field in the northwest section of the county. In November 1948, Humble Oil Company (now Exxon) opened the Bronte field in the eastern part of the county. In 1949 numerous wells were drilled, and the Bronte and Fort Chadbourne fields were proved. The latter field was shut down for thirteen months from February 1952 by the Railroad Commission to stop gas flaring. Production was resumed after the Lone Star Producing Company built a $3 million gas processing plant to utilize gas that was being wasted. Other oilfields drilled in the early 1950s included the North Bronte Multipay field; the McCutchen field, and the Wendkirk field. Production rose steadily into the 1950s but then began to drop. In 1948, Coke County produced almost 1,082,500 barrels of petroleum; in 1958, more than 12,795,000 barrels; in 1960, about 7,265,000; in 1978, almost 2,605,000; and in 1980, about 2,250,000. In 1990, production totaled 1,331,036 barrels. By 1991, since discovery in 1942, 209,281,131 barrels had been taken from Coke County lands. Tax money derived from oil profits helped the county to improve public services for its citizens. Modern schools were built in Bronte and Robert Lee; meanwhile, paving, road construction, and bridge improvements were made throughout the county. Oil money also helped to provide the county with a new courthouse, parks, and swimming pools.
The Robert Lee Dam, completed in 1969, impounded the E. V. Spence Reservoir which covers 14,950 acres and holds 488,750 acre-feet of water. Besides giving the Robert Lee area a reliable water supply, the lake is a valuable recreation site for fishermen, boaters, and swimmers. State highways 208 and 158 cross the county from north to south and east to west respectively, and U.S. Highway 277 crosses north-south through the eastern part of the county. Oil production accounts for the major share of income for the county. Income derived from its production is several times more than the county's income from agriculture. In the 1980s, Coke County maintained some 70,000 sheep and lambs and 30,000 cattle, along with smaller numbers of other livestock. About 500 acres were irrigated, and the county produced 47,000 bushels of wheat and more than 20,000 bushels of sorghum. Politically the county is stable in its voting habits; it was one of the sixty-two Texas counties that were still legally dry in 1986. By the late 1980s, Coke County had voted Democratic in every gubernatorial election since the 1950s, and had deviated to the Republican side only twice in presidential and senatorial elections (in 1972 and 1984). As of 2014, the population was 3,254. The county's smaller communities include Bronte, Blackwell (partly in Nolan County), Sanco, Silver, and Tennyson. Robert Lee is the county seat and largest town. Recreation in the county centers around hunting and fishing at Lake Spence and Oak Creek Reservoir.