Sherman County is in the High Plains region of the northern Panhandle on the Oklahoma border. The county's center lies at 36°50' north latitude and 102°30' west longitude. Stratford, the county seat, is in the northwestern part of the county eighty miles north of Amarillo. The county, named for Sidney Sherman, a veteran of the Texas Revolution, extends across 923 square miles of nearly level land covered by prairie grasses, some sagebrush, and yucca; elevations range from 3,200 to 3,800 feet above sea level. The area is drained by the North Fork of the Canadian River, which cuts across the northwestern corner of the county, and by Frisco, Coldwater, and North Palo Duro creeks. The area's soils are dark and loamy, with clayey subsoils that contain hardened calcium deposits. Temperatures vary from an average low of 31° F in January to an average high of 97° in July. The area receives an average of twenty inches of precipitation each year; the average growing season lasts 182 days. In 1982, 98 percent of the county's land was in farms and ranches, 45 percent of the agricultural land was cultivated, and 59 percent of the cultivated land was irrigated. Approximately 66 percent of agricultural receipts were from livestock and livestock products, especially cattle and hogs. Wheat, corn, barley, sorghum, and soybeans are the main crops, and mineral resources include caliche, natural gas, and petroleum. The county's road network includes U.S. Highway 54, which runs across the northwestern corner of the county; U.S. Highway 287, which runs north to south in the western sections; and State Highway 15, which crosses east to west across the center of the county and terminates at Stratford. Two railroad lines, the Atchison, Topeka and Santa Fe Railway and the Southern Pacific, pass through the county and intersect at Stratford.
In prehistoric times the Panhandle-Plains area was occupied by an Apachean culture; the modern Apaches occupied the area until about 1700, when they were pushed out by the Comanches, who dominated the Panhandle until the mid-1870s. During the early 1870s buffalo hunters entered the area and wiped out the great herds that once roamed the region. In 1876 the Texas state legislature established Sherman County from lands formerly assigned to Bexar County. The area was attached to Oldham County for administrative purposes until 1889. When first surveyed in 1874, alternate sections of the land were given to railroads as compensation for the survey, and the even-numbered sections were reserved for homesteaders. Partly because of the area's limited surface water and its distance from existing settlements, however, the population grew slowly. J. W. Rawlings built a bachelor's quarters near the Coldwater springs in 1874, and by 1880 cattlemen had begun to move in to graze their herds on the open range. The county was organized in 1889. Coldwater, a small settlement founded by the Loomis family near the center of the county, was designated the county seat by 1890. According to the United States census, there were thirty-four people living in Sherman County in 1890. The agricultural census for that year reported eight farms, encompassing 6,400 acres. There were about 500 cattle in the area, and no crops were reported. A small rock courthouse was built at Coldwater in 1891, and soon C. F. Randolf began to publish the Sherman County Banner, the area's first newspaper, there. During the 1890s much of the land in the county was incorporated into large ranches by men such as Dick Pincham, J. M. Turner, and William B. Slaughter. John Lanners, who settled on a claim under the Four-Section Act, ran a mule-drawn freight line between 1890 and 1898 to supply the area's ranchers. By 1900 there were eighteen ranches and farms, encompassing 195,000 acres, in the county, and the population had increased to 104. Cattle ranching dominated the local economy. Almost 30,000 cattle were reported that year, but only 2,880 acres were described as "improved," and no crops were reported. Farmers began to move into the area in numbers during the first years of the twentieth century, especially after 1901, when the Chicago, Rock Island and Gulf Railway built across the northwest corner of the county. Growth was also encouraged by the introduction of mechanized water-well drilling. The D. D. Spurlocks settled in the south central part of the county about this time, and the J. T. Brown family moved in with well-drilling equipment in 1902. The Norton family, from Kentucky, bought ninety-six sections of railroad land, which were managed for them by Walter Colton. Efforts to move the county seat to a site on the railroad began before the tracks were laid. Walter Colton, who owned a section of land on the line, formed a partnership with C. F. Rudolph to form a townsite (called Stratford) and to make it the new county seat. Their hopes were realized in an election held in May 1901, when voters chose to move the local government to Stratford. Opposition to the move was so strong that county officials transferred the county records in the middle of the night and held court in a tent in Stratford after midnight to make the move official. Bitterness between the factions caused Governor Joseph D. Sayers to order Texas Rangers to Stratford to keep the peace. By the time the rangers arrived, however, the district court suit had been dismissed and Stratford was generally accepted as the new site. A new newspaper, the Stratford Star, began to be published about this time.
The railroad set up the Standard Land Company to market its lands in Sherman County and elsewhere. From 1904 to 1909 Standard Land encouraged immigration into the area by offering excursion trips from Chicago for prospective buyers and setting up an experimental farm and ranch to demonstrate the area's potential. The Western Farm Land Company also subdivided lands in the county and offered excursions. By 1910 there were 165 farms and ranches, encompassing 303,000 acres, in Sherman County, and the population had grown to 1,376. Crop farming had also been established; 2,757 acres were planted in wheat that year, and 3,362 acres were devoted to sorghum. Ranching was still at the center of the local economy, although the number of cattle in the county had declined to 22,400. In 1908 the Pronger Brothers ranch introduced registered Hereford cattle into the county. Crop production continued to expand during the 1910s in spite of a drought in the first years of the decade, and expansion accelerated during the 1920s due to immigration and increasing farm mechanization. There was a particularly large influx of farmers from Oklahoma, Kansas, and other states between 1926 and 1928. Wheat became the county's most important crop; by 1930, 99,000 acres were devoted to the grain. As crop production expanded, the number of cattle declined somewhat but held fairly steady; 20,262 cattle were reported in 1920 and 20,772 in 1930. By 1930 there were 298 farms and ranches, and the population had increased to 2,314. Many residents suffered reverses during the Great Depression of the 1930s. The county gained another railroad link in 1930, when the Santa Fe built a line through the area, but drought severely hampered farming during the first years of the decade. In 1933 the area received only ten inches of rain, and during the mid-1930s its residents were caught in the Dust Bowl. Wheat production had fully recovered by 1940, however, when 130,000 acres were planted in wheat. Sherman County lost 10 percent of its population during the 1930s; by 1940 there were only 2,026 residents.
The pattern of periodic expansions of crop farming followed by drought-induced retrenchments continued during the two decades following the depression. Crop cultivation revived during the 1940s and then fell during an extended drought in the 1950s. Almost 168,000 acres of cropland were harvested in the county in 1940, more than 275,000 in 1950, and about 193,000 in 1960. In the 1960s large-scale irrigation was introduced, and a rapid expansion of crop farming ensued. The abundance of grain encouraged the establishment of big cattle feedyards in the late 1960s. In 1975 the county ranked seventh in the nation in per capita income. The population slowly rose to 2,443 in 1950, to 2,605 in 1960, and to 3,657 in 1970. Though oil was discovered in the county in 1938, petroleum production was relatively insignificant until the late 1970s. Only 28,000 barrels of crude were produced in the county in 1960, for example, and as late as 1974 only 8,000 barrels were produced. Almost 167,000 barrels were produced in 1978, however, and 104,000 barrels in 1982. Meanwhile natural gas production became an important element of the local economy. In 1982 more than 441,151,000,000 cubic feet of gas-well gas and almost 285,000,000 cubic feet of casinghead gas were produced in Sherman County. In the 1980s the county's 750 producing gas wells and several producing oil wells furnished 60 percent of the school tax base. Nearly 756,000 barrels of oil were produced in the county in 1990 and almost 202,000 in 2000; by January 1, 2001, 8,685,750 barrels of petroleum had been taken from Sherman County land since 1938.
The voters of Sherman County supported Democratic candidates in virtually every presidential election between 1892 and 1948, except in 1896, when Republican William McKinley narrowly carried the county, and in 1928, when Republican Herbert Hoover bested Democrat Al Smith. The county's sympathies shifted in the 1950s, however, and Republican candidates carried the county in every presidential election from 1952 through 2004. In the 1980s Stratford Feedyard, the largest feedlot in the county, had a capacity of 80,000 head and used 1,500,000 pounds of grain a day. Other feedyards in the area included Walter Lasley and Sons, Dean Cluck, and Jack Freeman. In 2002 the county had 322 farms and ranches covering 546,237 acres, 59 percent of which were devoted to crops and 30 percent to pasture. In that year farmers and ranchers in the area earned $295,070,000; livestock sales accounted for $247,624,000 of the total. Beef and stocker cattle, corn, wheat, sorghum, and alfalfa were the chief agricultural products. Sherman County's population dropped to 3,164 by 1980, then rose slightly to reach 3,185 by 1990. The census counted 3,084 people in the county in 2014. About 55.5 percent were Anglo, 0.9 percent African American, and 42.3 percent Hispanic. Communities include Stratford (population, 2,050), the county seat, and Texhoma, which straddles the Texas-Oklahoma border (352 on the Texas side). Nothing except a tiny cemetery is left of Coldwater, the original county seat. Irrigated crops furnish cover for game birds, and pheasant season in December attracts hunters from all parts of the country to the area.