Hall and Hall
The ranch, which includes a 9,500-square-foot house inspired by a Frank Lloyd Wright design, is located in Steamboat Springs, Colorado and is a haven for local wildlife like bald eagles and deer.
Mitchell spent decades working with computers and became wealthy enough to buy the ranch and his own plane.
"I got into computers in the early days and wrote my fist line of code in 1962," he told the WSJ.