Dr. William Harris of Laramie established the TA Ranch in 1882, purchasing the brand and herd from Tom Alsop and driving cattle north to Johnson County. Harris never lived here himself, remaining in Laramie to practice medicine while Charles Ford managed the operation. This absentee arrangement aligned Harris with the large cattle barons of the Wyoming Stock Growers Association, men who ran vast herds on open range and viewed the growing number of small ranchers and homesteaders as a threat. The original barn, built that first year, still stands with its log-and-frame construction. A large root cellar went in the same year. The ranch was one of the first in Johnson County, documenting the early expansion of cattle ranching across Wyoming.

By 1892, tensions between the cattle barons and small landowners had reached a breaking point. The stockmen accused the newcomers of rustling. The locals saw the accusations as a cover for driving them off the land. In April, the Wyoming Stock Growers Association assembled a small army: hired guns from Texas, stock detectives, and sympathetic cattlemen. They traveled north by special train, then set out to eliminate suspected rustlers. The mercenaries killed two men at a cabin on the KC Ranch before word spread across Johnson County. An armed force of local settlers and cowboys mobilized to confront them. The invaders, outmaneuvered and outnumbered, retreated to the TA Ranch.

The gunmen fortified the ranch. They cut gunports in the upper walls of the barn, holes that remain visible today. On elevated ground west of the barn, they dug trenches commanding views of the surrounding country. The locals surrounded them and built their own breastworks, at least ten positions encircling the ranch. Three of these earthworks survive. Inside the ranch house and barn, roughly fifty invaders waited. Outside, nearly four hundred Wyomingites wanted blood. Shots cracked across the prairie. The siege stretched through three days. The standoff ended only when the U.S. Cavalry rode in from Fort McKinney, rescuing the invaders before the locals could storm the fortifications.

Harris traded the ranch to J.P. Gammon in 1904. Gammon raised Percheron draft horses, later switching to Hereford cattle and adding hogs in the 1920s. The ranch expanded with new structures: a log cookhouse in 1904, a milk barn, meat house, hog house, and cattle shed in 1915. The Long Brothers took ownership in 1979, followed by other hands. In 1991, private owners purchased and restored the property. Today the TA operates as a working cattle ranch, guest ranch, and restaurant. Visitors are welcome to view the barn with its gunports, the ranch house with its bullet scars, and the quiet trenches where desperate men once waited for deliverance or death beneath the Big Horn Mountains.