In 1851 the United State Army established Fort Belknap on the Red Fork of the Brazos River. The Brazos Indian Reservation was surveyed in 1854 twelve miles southeast of the fort. Among the 1200 Indians living there were Caddoes, Anadarkos, Wacos, and Tonkawas, each with their own villages and all relieved to have protection from the Comanches. The Indians were removed to Indian Territory in July, 1859. Young County was also a stop on the Butterfield Overland Mail route from 1858 to 1861. The new town of Graham was chosen as the county seat in 1873. Stockmen gathered at Graham in 1877 to form the Stock-Raisers' Association of North-West Texas (later known as the Texas and Southwestern Cattle Raisers Association). Young County is also the home of the largest live oak tree in the nation, estimated to be 500-750 years old. The tree stands 48 feet tall and has a circumference of 357 inches.

The economy of Young County is supported by agricultural crops of beef cattle, wheat, hay, cotton, and pecans. Minerals include oil, gas, sand and gravel. Oil exploration and production rapidly shaped the economy and actual production of petroleum began in 1920. Recreation opportunities include activities at Possum Kingdom Lake, exceptional hunting throughout the year, and tourism. Young County Arena attracts many entertainig events such as rodeos, tractor pulls, circuses, indoor motocross and others.