The Flying V Guest Ranch, or Cambria Casino-Park Memorial as it was originally called, is a resort in the western foothills of the Black Hills of northeast Wyoming. The main physical structure at the Flying V resort is a two-story, sandstone lodge, English Tudor in its general design. It is a modest, somewhat eclectic, version of an English manor house of the sixteenth century. The original purpose of the Flying V, which was constructed in 1928, was to serve as a memorial to the miners and traditions of Cambria, a mining operation north of present-day Newcastle, Wyoming. Before the mines were shut down plans were made by the Cambria Fuel Company to erect the memorial. The facility was opened in piecemeal fashion, the grand opening of the dance hall being held on January 12, 1929. The casino was situated on 2,280 acres of land donated by the company, and had a subsidiary ranch of 15, 560 acres. A fresh water pool supplied by the water of Salt Creek, and a salt water plunge supplied by water piped from a salt springs two miles north of the casino, were primary features of the complex. Seventy-five guests could be accommodated in six cottages, which no longer exist, and the main casino building. In 1936-37 a room at the casino was leased for use as a bar. From 1939 to 1949 the Flying V Ranch was leased to the Reno Livestock Company. Since 1949 the Flying V has been under various ownership.

Jenney Stockade is best knows as a stage station on the Cheyenne to Deadwood Stage Line. However, its history dates back to 1857. During that year Lt. G. K. Warren, accompanied by geologist Dr. F. V. Hayden, became the first white men to occupy the site. They camped on the east bank of Beaver Creek and Warren constructed a log corral at the camp. From this semi-permanent camp the Warren party proceeded to explore the Black Hills for mineral wealth and represented the first authorized military expedition into the Black Hills some seventeen years before the famed Custer Expedition.

March 17, 1875, 75 geologists and miners headed-up by Professor Walter P. Jenney left Cheyenne for the Black Hills. At Fort Laramie the Jenney party joined forces with 432 soldiers under the command of Lt. Col. Richard I. Dodge. The group arrived at the old Warren campsite on June 3, 1875 and the construction of the log fort began that day. The building of Camp Jenney, named after Professor Jenney, was completed in ten days. It was used during the summer of 1875 as a supply depot for all the camps throughout the Black Hills. In June of 1877, a cut-off on the Cheyenne to Deadwood Stage Line from Hat Creek, via Old Woman's Fork, to Camp Jenney was completed by W. M. Ward. Located 56 miles south of Deadwood, Camp Jenney became a regular stage stop on the Cheyenne to Deadwood run. The station became known as Jenney Stockade and beginning April 10, 1877 the stages made night runs between the stockade and Hat Creek Station. Jenney Stockade then became a breakfast and supper stop for stage passengers.

On June 22, 1877, the land on which Jenney Stockade stood became the property of Flarida, Burroughs and Spencer. Spencer obtained Flarida's and Burrough's interest and the LAK (Lake, Allerton and Spencer) Cattle Company was established during the winter of 1877-1878. In the following years the Stockade served the owners of the LAK Ranch until the construction of modern buildings necessitated moving the old original stockade structure to Newcastle.

The Newcastle Commercial District is eligible under Criterion A because it is related to the late nineteenth and early twentieth century growth and commercial development of the City of Newcastle, the county seat of Weston County. West Main Street (U.S. Route 16), around which the commercial district was built, became the original route of the Black and Yellow Trail, one of America’s first transcontinental auto highways. This major transportation route that connected the Midwest to Yellowstone National Park brought tourist and commercial traffic to the county and city, all of which added significantly to Newcastle’s economy. The commercial district of Newcastle suffered from a number of devastating fires, which resulted in the loss of several buildings. However, these fires are also an important facet of the history of Newcastle, and succeeding eras of economic growth resulted in the construction of new commercial buildings to fill the voids. The last significant growth occurred during the oil boom period of the 1940s and early 1950s. The Newcastle Commercial District is also eligible under Criterion C because the buildings in the district represent a wide array of architectural styles from Late Victorian Italianate commercial buildings to Streamline Moderne, Neo-Classical, Beaux-Arts, and Mission influences. Many are well preserved and retain good exterior physical integrity. The Newcastle Commercial District retains the flavor of a small early-to-mid twentieth century American downtown with a concentration of diverse commercial and public buildings clustered along its main street. Large commercial chains, plazas, and strip malls have not encroached on the vital downtown, and modern infill has been eliminated by careful drawing of the district boundary.

This thematic study includes twelve post offices owned and administered by the U.S. Postal Service (USPS) throughout the State of Wyoming. These include the Basin, Greybull, Douglas, Lander, Torrington, Thermopolis, Buffalo, Kemmerer, Powell, Yellowstone, Evanston, and Newcastle Main Post Offices. The buildings represent a continuum of federally constructed post offices allocated to the state between the turn of the century and 1941. The buildings exhibit a variety of styles and sizes but maintain a common demeanor representative of the federal presence. All of the buildings were constructed from standardized plans developed from guidelines provided by the Office of the Supervising Architect in the Treasury Department. Variations in design styles reflect both the transition in the design philosophies of the Supervising Architect and the requirements developed in response to the Depression. These variations in design, as well as functions are also somewhat related to the communities in which they were placed and reflect the economic, political, and governmental context of those communities.

The Weston County Courthouse is a two-story Classical Revival building with Beaux Arts details designed by Wyoming architect Charles A. Randall and constructed in 1910-1911. The Courthouse is important for its association with and representation of the broad patterns of development in Newcastle's early years as a county seat. As is typical in communities throughout the west, Newcastle experienced the usual success enjoyed by a town once it became the ''county seat.'' The role of the courthouse in extending to the community of Newcastle a relative stability as the county seat in a somewhat economically marginal environment has made a significant contribution to the broad patterns of local history. The courthouse remains as the most beautiful and imposing structure in Weston County, nobly representing Weston County government's role in shaping this community from 1890 to the present day.

The Anna Miller Museum Building was originally a stable and residence constructed for the National Guard's horses and caretaker. Constructed between 1933 and 1936, the building is one story tall with a rock faced exterior of native sandstone laid in courses. The stone work was done by the Sundstrom Brothers, craftsmen from the area. These same stone masons cut and laid the stone for the construction of the Weston County Court House. The building is significant for its association with and representation of the National Guard's important role in the community of Newcastle and in Wyoming history. The Newcastle National Guard unit has historically made significant contributions to the broad patterns of Newcastle's economic and social stability. The National Guard continued its service to the community by permitting the Weston County Historical Society to use the stables as a museum in 1966. It is the last National Guard cavalry stable known to exist in Wyoming.