Napoleon Warren “Boss” Chilson, Judy’s grandfather, had ranch holdings with his brothers in the Tonto Basin, south of Payson, as early as 1913. In 1924, he purchased the first summer permits, Hay Lake and Little Springs, plus numerous homesteads.

Since most of the Bar T Bar lies south of the Hay Lake and Little Springs grazing permit area, the ranch soon pursued acquiring more deeded land and contiguous land, with the goal of eliminating the 70-mile cattle drive between Little Springs and the Tonto Basin (which required numerous 7–10 day treks through downtown Payson each year). As the move to the north continued, they purchased the Pitchfork Ranch from the Babbitt Brothers in 1939. The Pitchfork probably accounts for most of the northern portion of the present day Bar T Bar. It included the lands around Meteor Crater. Several years later, in 1941, the families acquired a 199-year lease on the Meteor Crater property from the Barringer Family. Other significant purchases between 1937 and 1946 included the Wolfolk allotment, two townships in the area, which provided the connection between the summer and winter ranges, and Moqui Ranch, all from Fred Bixby.

Ernest Chilson, Judy’s father, was instrumental in building the waterworks that keep water in front of the livestock and wildlife that make their home on the Bar T Bar. Soldier Annex Dam was enlarged in 1940 to store 2,600 acre-feet of water. The supply canals from Canyon Diablo to Soldier Lake were constructed. In 1942, the Chilson Canal was built, connecting Soldier Annex Dam to the Hay Lake headquarters, a distance of 7 miles. Tremaine Dam was built by Bar T Bar in 1950 to store more runoff for the irrigated pastures. Water is transmitted to over 60 stock ponds in the winter country on state and private land through 73 miles of canals and ditches, providing relatively permanent water for 80,000 acres of rangeland.

In 1952, Ernest launched the first large-scale juniper-management program in Arizona. This aggressive program continued for 16 years. Some 40,000 acres were treated in several manners, but primarily cabled/chained, piled, and burned.

In 1990, the Prosser and Chilson families purchased most of the ranch properties from their partners, the Tremaines. Properties that were not purchased included Moqui Ranch and the most of the Hay Lake farmlands. To make up the loss of summer grazing land, Bar T Bar, Inc., purchased the adjacent Lost Eden Allotment in 1996 from the Kennedy family.

With the generational transition to the Prossers, Angus and Gelbvieh were integrated into the traditional Hereford herd in the 1980s — hence, the versatile Balancer cattle of today. Over the years, Beefmaster, Brangus, and Santa Gertrudis have been incorporated in a portion of the herd to produce Southern Balancers ™ for customers seeking more heat tolerance.

Currently, steer calves and bred commercial replacement heifers are merchandized in the fall, and registered bulls in the annual spring bull sale, typically the first Saturday in April. Steer calves go into the Country Natural Beef program, and the aged cows and bulls go to ground beef for Diablo Burger Restaurant and Diablo Beef Retail sales.

Bar T Bar has had a long tradition of ranch improvements that benefit both wildlife and their livestock, to include: grassland restoration, water development, and incorporation of a variety of grazing systems.

In the very recent years, an additional 34,000 acres of piñon-juniper country have been treated on private, state, and federal land to benefit pronghorn antelope and livestock. Pipelines have been added and extended. In 2016, a pipeline was extended by 10 miles and 16 drinkers were added to provide a more reliable water supply and reduce stress on livestock.  A circular pivot irrigation system waters the deeded acreage at Hay Lake. These projects are ongoing. Bar T Bar is proud of its long history of improving its resources.