Spear-O-Wigwam Ranch is significant under Criterion A in entertainment/recreation for its association with dude ranching in the Bighorn Mountains from the 1920s through the early 21st century. Dude ranching was an important economic activity that brought hundreds of visitors from the East to the Bighorn Mountains and other areas of Wyoming, many of whom eventually settled in the area and contributed greatly to the culture and economy of the state. In addition to contributing to local economies and attracting investors to the state, dude ranching has been credited with helping preserve western traditions such as hunting, fishing, pack trips, campfire gatherings, round-ups and brandings. As one of the longest surviving dude ranches in Sheridan and Johnson counties, Spear-O-Wigwam represents the 'Golden Age of Dude Ranching' in the 1920s, as well as its survival into the early 21st century. When Spear-O-Wigwam closed as a dude ranch in 2011, it was one of only five early 20th century dude ranches from the 'golden age of dude ranching' still operating in the area. The period of significance begins in 1923, when Willis Spear first began inviting guests to his cow camp for fishing and hunting, and ends in 1947 when the Spear family sold the property, ending twenty-four years of Spear family ownership and ending the excursions to the Spears' Montana ranches and the Crow Reservation. The property is also significant under Criterion C for its rustic-style dude ranch architecture, especially the multi-sided lodge in the shape of the ranch's brand, a spear extending from a "wigwam." This and other buildings on the property were designed and built by the owners and their employees, although there is evidence that a professional architect contributed to the design of a 1933-1934 addition to the lodge. The historic log buildings date from 1924 to 1938. It has additional significance in landscape architecture for its layout and setting representative of Western dude ranches of the early 20th century. - NRHP