Henry S. Boice, rancher and manager of the XIT Ranch, was born in Las Vegas, New Mexico, in 1860, the son of a local physician. He began working as a cowboy at age fifteen for fifteen dollars a month. Since his contemporaries were mostly native New Mexicans, he spoke mainly Spanish throughout his youth. Beginning in 1878 Boice worked for Henry W. Cresswell's ranch near Pueblo, Colorado, where he became foreman at age twenty-one and subsequently Cresswell's partner. Boice also ran his own cattle, branded LK connected. When Cresswell drove his herd down to the Panhandle of Texas, he put Boice in touch with David Berry, a New York financier, who also owned a herd in Pueblo County. The result was the formation of the Berry-Boice Cattle Company, in which Boice managed the range and supervised the buying and selling of cattle.
In 1881 Boice moved the company herd, branded with three sevens, to a choice range along Palo Duro Creek in Ochiltree and Hansford counties. The Three Sevens Ranch was mainly a steer operation, and Boice contracted for steers throughout the Southwest, purchasing 25,000 a year. Most of these were shipped from the Panhandle to ranges in North Dakota. Because of his extensive travels, he gained perhaps the widest knowledge of ranchers and cattle among his contemporaries. Cresswell and other Panhandle ranchers were counted among his circle of friends. In 1885 Boice trailed the remainder of his Three Sevens cattle to North Dakota and closed out his Panhandle operation. By that time the Berry-Boice Company was operating on a grand scale, mostly in the badlands along the Little Missouri River. There Boice became acquainted with Theodore Roosevelt and Gregor Lang, whose ranches bordered his own. By 1896 Boice was the leading shipper of grass-fed young steers through the Chicago commission firm of Clay, Robinson and Company.
Boice was among the first to buy purebred bulls and breed up his stock. The Kansas firm of Gudgell and Simpson, established in 1879 to import bulls for breeders, sold him several prize bulls, especially Herefords. Boice went to Independence, Missouri, to do business with Charles Gudgell, and met Gudgell's daughter LuBelle, whom he married in 1891; they had three sons and two daughters.
When the Berry-Boice Company closed out in 1897, Boice formed the H. S. Boice Cattle Company and purchased the Beatty brothers' ranch, with headquarters at Point of Rocks on the Cimarron River, near the point where the Oklahoma, Kansas, and Colorado boundaries meet. The firm shipped from the railroad towns of Texhoma and Arkalen, Oklahoma, a fact that necessitated a drive of more than a hundred miles to load the cattle. Since only Hereford bulls were used, Boice's herd grew in both quality and quantity during the decade of the ranch's existence. Although his family resided at Kansas City most of the year, they spent summers at Point of Rocks, where the sons gained valuable ranching experience. During this period Boice and several partners formed a livestock loan and commission company in Kansas City, but this enterprise soon fell into financial straits, and the partners lost everything. Boice accepted the general managership of the XIT Ranch in 1905 and moved his family to Channing, in Hartley County, Texas. By 1906 he had closed out the H. S. Boice Cattle Company, and two years later he began investing in the Block Ranch, in the Carrizozo-Roswell area of New Mexico, and the Chiricahua Cattle Company in southern Arizona. Boice remained with the XIT until it closed out its cattle operations in 1912. As the Capitol Freehold Land and Investment Company's last general manager, he won a reputation for his refusal to smoke, drink, or swear and for possessing "a will like a rock." R. L. Duke was among the range foremen who worked under him.
After 1912 Boice and his family settled at the Chiricahua (CCC) Ranch, which he and his partners reorganized as the Boice, Gates, and Johnson Cattle Company. Boice died on the ranch in December 1919. His two oldest sons, Henry and Frank, and their sons continued Boyce's successful efforts at improving their stock of purebred Herefords.