The historic Jensen Ranch is located in Sublette County near the town of Boulder, Wyoming. The ranch complex consists of a cluster of dwellings, barns, outbuildings, pole corrals, and barbed wire fences. The ranch is dominated by a wood frame Foursquare ranch house which was constructed in 1918 by Metinus Jensen. The Jensen Ranch is a pioneer cattle ranch which represents the themes of early 20th century settlement and agricultural development on submarginal lands in Sublette County and the State of Wyoming. Submarginal lands were settled late, after the more attractive and better watered lands had already been claimed.

Danish immigrant Metinus Jensen settled the area in 1905 and gradually built a successful beef cattle operation. The Jensens were neither political leaders nor the county's wealthiest cattle barons, but they helped form the real foundation of Sublette County's ranching community, persevering against an inhospitable climate on marginal lands far from the nearest railhead. The Jensen Ranch has remained a working cattle ranch and has been owned and operated by the same family for three generations.

The New Fork townsite consists of several log and wood frame structures representing one of the earliest settlements and commercial centers in the isolated upper Green River Valley. The small ranching settlement was established by John Vible and Louis Broderson in 1888 near the New Fork and East Fork Rivers. Both men were Danish emigrants who had come to America in 1884. They met while working on the Oregon Shortline in western Wyoming and Idaho. The two men pooled their meager resources into an informal partnership. They planned to file on homesteads in order to raise cattle and to start a mercantile business by locating a store close to the Lander Cut-off of the Oregon Trail. The partners built a small log structure which served as the store, trading post, and living quarters. The location became known as New Fork. By the end of 1908 the town boasted a school, a saloon, a hotel, a barbershop, a livery and a blacksmith shop, and a woodframe house with a bay window owned by the saloon keeper Frank Seabolt, in addition to the Vible stores and residence. In 1909-1910 John Vible contracted with locally prominent carpenters to build a large frame dance hall. He named it Valhalla after the Norse Heaven populated by heroes slain in battle. The dance hall became the focal point of community activity including dances and political rallies.

By 1918 the post office was discontinued and mail was then delivered to nearby Boulder. New Fork had gradually been eclipsed by other communities, including Pinedale which became the county seat when Sublette County was created in 1921. Transportation patterns had changed over the years, and the Lander Cut-off fell into disuse. Railroad transportation never reached the upper Green River Valley. A scarlet fever and diphtheria epidemic struck the Vible family in late 1915, and John Vible, his daughter and two elder sons died within a period of two weeks. These factors contributed to the demise of New Fork.

As an 1886 homestead complex, the Steele Ranch is one of Sublette County's best remaining examples of an early homestead/ranching operation that has been passed from generation to generation. It is an excellent representative of the cattle ranching frontier which contributed significantly to the broad patterns of Wyoming settlement and development. It is associated with the Steele family, locally significant for their involvement in local politics. The ranch also embodies the distinctive characteristics of type, period, and method of construction typical of high plains ranching.

In 1886 Ed P. Steele and a friend of his traveled from Boulder, Colorado, to South Pass City in order to try their luck in the gold mines. They continued on over to the eastern part of the Green River Valley and searched for gold there. One mile below the confluence of Silver Creek at the base of Fremont Butte, five miles east of Boulder, Wyoming, they built a cabin on the East Fork River. On August 15, 1888, the rest of the Ed P. Steele family including 75 head of cattle arrived at the cabin. The Steeles filed and bought more land until they eventually operated 3,000 acres with 600 head of cattle and 100 horses. The original homestead cabin has evolved from the one-room cabin built in 1886 to an eight room log structure, whose last addition was constructed in 1908.