Ochiltree County is in the far northern Panhandle, bordered on the north by Oklahoma, on the east by Lipscomb County, on the south by Roberts County, and on the west by Hansford County. The county is in the heart of the High Plains, with its center at 36°17' north latitude and 100°49' west longitude. Perryton, the county seat, is in the north central part of the county, 120 miles northeast of Amarillo. The area was named for William Beck Ochiltree, a Republic of Texas judge, secretary of treasury, and an officer in the army of the Confederacy. The county occupies 907 square miles of level prairies cut by Wolf Creek, which runs eastward from the center of the county; by South Wolf Creek, which runs northward into Wolf Creek from the south central part of the county; and by Palo Duro and Chiquita creeks, which flow northward into Oklahoma from the northwestern corner of the county. These streams are all intermittent. The rich clay and loam soils support abundant native grasses as well as wheat, grain sorghum, corn, and alfalfa. Oil and gas are produced in substantial quantities. Elevations range from 2,600 to 3,100 feet above sea level, and the county's annual average rainfall is 20.48 inches. Temperatures range from an average minimum of 18° F in January to an average maximum of 93° F in July. The average growing season lasts 191 days. A modern highway system focusing on Perryton developed between the 1930s and the 1950s. U.S. Highway 83 runs from Liberal, Kansas, to Perryton, then on to Canadian, and U.S. Highway 70 runs from Perryton south to Pampa. State Highway 15 runs east to west across the county, parallel to the Santa Fe Railroad, and various farm-to-market roads link the major routes to the rural area.
Prehistoric cultures occupied this region, then the Plains Apaches appeared. The historic-era Apaches arrived, then were pushed out of the region in the early eighteenth century by the Comanche Indians, who dominated the Texas Panhandle until the 1870s. The Red River War of 1874–75 led to the removal of the nomadic Indians to Indian Territory, which in turn led to the arrival of the ranching era. In 1876 the Texas legislature established Ochiltree County from lands formerly assigned to the Bexar District. Ranching arrived a little later in Ochiltree County than it did farther south in the Panhandle. By 1885 Henry W. Cresswell had purchased or leased most of the county and established the Cresswell Ranch (Bar CC) on Wolf Creek in the eastern part of the county and moved its headquarters from Roberts County to the new site on Wolf Creek. His company, the Cresswell Land and Cattle Company of Colorado, was syndicated as the Cresswell Ranch and Cattle Company by 1885. The Cresswell Ranch controlled most of the land in the county. Dee Eubank and Tom Connell, who arrived on Wolf Creek in 1879, controlled much smaller acreages in the eastern part of Ochiltree and the western part of Lipscomb counties. After the blizzards of 1886–87 county lands were opened to settlement by stock farmers who operated on a much smaller scale. The availability of land in Ochiltree County coincided with the proximity of a new railroad. In 1887 the Southern Kansas Railway Company of Texas, a Santa Fe subsidiary, built a line from Kansas through Oklahoma into the Panhandle via Canadian and Panhandle. This line passed through Lipscomb County, thirty to forty miles east of Ochiltree. Thus the county was only one or two days' travel from the railroad. Proximity to the railroad brought an influx of settlers into the county, especially after 1900, and the ranching economy evolved into a stock-farming system. Between 1890 and 1900 the number of ranches in the area increased from forty-seven to seventy-one, and the number of cattle grew from 10,000 to 84,000. At the same time the area's population rose from 198 to 267. Almost no crops were grown in the area at the beginning of the twentieth century, though some ranchers did grow corn and vegetables for their own consumption. Between 1900 and 1910, however, stock farming began to give way to wheat farming. As local stock farmers determined that wheat was a viable crop and new settlers moved into the area, the local economy shifted. By 1910 there were 264 farms and ranches in the area, encompassing almost 226,000 acres, including more than 53,000 acres reported to be "improved." That year the agricultural census reported 9,000 acres planted in wheat in the county; another 2,075 acres were planted in corn, and 7,400 acres were devoted to sorghum. By the beginning of World War I Ochiltree County possessed a diversified agricultural economy poised for expansion. By 1920 there were 336 farms and ranches; almost 42,000 acres were planted in wheat, and 14,500 acres devoted to sorghum. Poultry raising was also becoming significant to the economy by this time; in 1920 23,000 chickens were reported on county farms. Cattle ranching continued but was less important than it once had been. About 24,000 cattle were reported in the county that year.
The urban development of Ochiltree County reflects its evolution from a ranching to a mixed economy. The sparse ranching population of the 1880s and 1890s revolved around the village of Ochiltree, in the central part of the county fifteen miles south of the site of present Perryton. Ochiltree, founded in 1885, became the county seat in 1889, when the local residents decided to organize the county. By 1915 the town had a population of 500, a courthouse, a jail, a school, a bank, and two churches. The population of the county as a whole grew to 1,602 by 1910 and to 2,331 by 1920. The construction of the North Texas and Santa Fe Railway, a Santa Fe subsidiary, from Shattuck, Oklahoma, to Spearman, Texas, in 1919 altered the county permanently. The rail line, which ran across the Texas Panhandle, tapped the newly emerging wheat market. The post-World War I demand, coupled with access to rail transportation, made wheat farming profitable. Another influx of farmers between 1920 and 1930 took advantage of these circumstances. By 1930 there were 580 farms and ranches in the county, and almost 210,000 acres were planted in wheat, the county's most important crop by far. Reflecting this expansion, the area's population rose to 5,224 by 1930. As the population and economy grew, other changes occurred. Ochiltree, fifteen miles south of the railroad, found itself at a distinct disadvantage when a new town, Perryton, was laid out on the railroad in 1919; Perryton was immediately made the county seat. During the next year the entire town of Ochiltree was moved to Perryton, and by 1920 Ochiltree had disappeared completely. The new railroad also changed the location of Wawaka, which had been established in the west central part of the county by German immigrants in 1885. In 1919 and 1920 this tiny community moved three miles north to the railroad and shortened its name to Waka.
Ochiltree County suffered from the effects of the Great Depression and the Dust Bowl of the 1930s. By 1940 there were only 528 farms in the county, and the number of acres devoted to wheat had declined substantially; only 67,000 acres were planted in wheat that year. The population dropped from 5,224 in 1930 to 4,213 in 1940. The economy recovered during the 1940s, and the discovery of oil and gas in the southern part of the county in 1951 led to increased growth. Although oil and gas exploration had occurred in the county as early as 1912 and continued periodically through the 1920s and 1930s, the first successful major producer blew in 1955. In 1956 more than 341,500 barrels of crude oil were produced the county, and production rapidly expanded: the county's wells produced 4,644,000 barrels in 1960, 5,212,000 barrels in 1965, 4,913,000 barrels in 1974, 2,2,844,000 in 1978, and 3,012,000 in 1982, and 1,716,000 barrels in 1990. By January 1, 2001, 156,388,656 barrels of oil had been produced in the county since discovery in 1951. These petroleum discoveries led to a boom in the local economy and population. The 1950 population of 6,024 jumped to 9,380 by 1960 and to 9,704 by 1970. It began to decline in the 1970s, however, as the oil boom faded: to 9,588 by 1980, to 9,128 by 1990, and to 9,006 by 2000.
The voters of Ochiltree County supported the Democratic candidate in almost every presidential election between 1892 and 1948; the only exception occurred in 1928, when they supported Republican Herbert Hoover over Al Smith. In every presidential election between 1952 and 2004, however, the county went Republican. In the mid-1980s Ochiltree County possessed a diversified economy centered around agriculture, oil, and gas. The agricultural sector earned $70 million in 1983, primarily through the production of cattle, hogs, wheat, sorghums, corn, and alfalfa. Irrigation, which began in the late 1940s and expanded in the 1960s and 1970s, was used on 40 percent of the county's croplands in the early 1980s. In 2002 the county had 367 farms and ranches covering 559,479 acres, 63 percent of which were devoted to crops and 36 percent to pasture. In that year farmers and ranchers in the area earned $241,852,000, and the county ranked first in the state for wheat acreage. Cattle, swine, corn, wheat, and grain sorghum were the area's other chief agricultural products. Feedlot operations, agribusinesses, and oilfield services also added to the local economy. As of 2014, 10,758 people lived in the county. Of those, 46.4 percent were Anglo, 0.9 percent African American, and 51.2 percent Hispanic. Communities in the county include Perryton (population, 9,349), the seat of government; Waka (65); and Farnsworth (130).