The Sheridan Flouring Mills, Incorporated was originally constructed by J. W. Denio in 1920-21. It is an elongated rectangular reinforced concrete building with a two-story south wing, a central six-story segment, and a two-story brick element on the north end. These components represented the milling, packaging, and storage portion of the flour mill. There is a narrow intervening open space between the north end of the building and a reinforced concrete grain elevator and smokestack and seven pairs of attached grain storage tanks. In 1978 the mill was converted to a motel, which is now known as the Mill Inn. The south side of the elevator still bears a multi-colored logo with a cowboy on a bucking bronco and mountains in the background. The sign reads ''Best Out West Enriched Flour, Tomahawk Feeds For Livestock and Poultry, Sheridan Flouring Mills Inc.''

The Sheridan Flouring Mills, Inc. represents one of the most important early commercial enterprises in the City of Sheridan and Sheridan County. It served not only Sheridan but also the surrounding agricultural region including southeastern Montana and northeastern Wyoming through its network of farmers and grain elevators located along the mainline of the Chicago, Burlington and Quincy Railroad. It encouraged the growth of different strains of wheat by local farmers and provided a reliable market for their crops. It also converted these raw materials into flour, livestock feed, and other products to service the demands of the local community, as well as a much larger national market that extended from coast to coast. It became one of Sheridan's largest and most enduring employers with a substantial payroll and was also one of the largest taxpayers in Sheridan County and in the State of Wyoming. It provided a substantial income for the hundreds of farmers in the region who depended upon the mill as a buyer for their agricultural products. At this location, the Sheridan Flouring Mills, Inc. served Sheridan and the surrounding region from 1921 until finally closing in 1972.

The Sheridan Inn represents the establishment of modern culture in areas still ''wild and woolly'' prior to the coming of the railroad. When the Sheridan Inn opened in 1893, it was said by many to be the finest hotel between Chicago and San Francisco. It immediately became the social center for the Big Horn country area which at that time attracted many big game hunting parties, including notables from all parts of the United States. The Chicago, Burlington, and Quincy Railroad built into Sheridan, Wyoming, and constructed the hotel as a feature of its development program. George Holdrege, general manager for the railroad, conceived the idea for the hotel and gave to Thomas R. Kimball, an architect of Omaha, Nebraska, the task of designing the structure. Kimball modeled the Inn generally after a Scottish inn that he had visited and liked. The Sheridan Inn is credited with having had the first bathtub and electric lights in that part of Wyoming. William F. Cody, better known as Buffalo Bill, is said to have led the grand march at the opening of the Inn. He operated the Inn from 1894 to 1896.

Located on Main Street between Burkitt and Mandel Streets, the Sheridan Main Street Historic District comprises architecturally and historically significant buildings dating from the late 19th century to the early 20th century, with the majority of its buildings constructed in the 1910 and 1920 periods. Mixed elements from different classical styles are characteristic of the architecture. Sheridan was platted as a town by John D. Loucks in 1882. Loucks was said to have platted the town on the back of a sheet of wrapping paper by the tallow of a candle. Once the town was platted, it was then approved and incorporated in 1884. By the end of 1884, most of the lots of the original forty acre plat of the Sheridan townsite were occupied. As the Main Street Historic District was part of the ''original town'' and the survey maps still list the southern part of Main Street as ''original town,'' one can easily see that Main Street grew to the north as the town increased in population. In 1890 Sheridan had a population of 281 and by 1900 there had been a 455% increase to 1559 with the coming of the railroad, the opening of many coal mines in the vicinity of Sheridan, the arrival of townspeople, and the settling of ranchlands. By 1907 the City of Sheridan had a population of 4927. Sheridan as a business community was thriving during the first twenty years of the 20th century and Main Street was the center for trade, commerce, and government for the city and the county.

The Sheridan Railroad Historic District extends to the north and east of the original commercial district of Sheridan and comes within one block of the north end of the Main Street Historic District. The district extends along Broadway adjacent to the Burlington Northern Railroad tracks (originally Chicago, Burlington and Quincy) from Grinnell Street north to Sixth Street. Structures within the district are primarily residential, with a few commercial and railroad-related industrial (warehouse) buildings. Most structures in the district are in one way or another connected to the railroad that runs along the eastern edge of the district.

The district constitutes the historic transportation hub for the city and surrounding communities. It is also significant in community planning and development, as it includes a well-preserved, late 19th to early 20th-century working class neighborhood. The centerpiece of the district is the Sheridan Inn, which opened in 1893 and is now listed as a National Historic Landmark. Immediately southeast of the Inn is the 1912 Chicago, Burlington and Quincy Railroad depot. The original wooden railroad depot, built in 1892, lies directly northeast of the Inn.

St. Peter’s Episcopal Church is one of the few historic churches remaining in Sheridan designed in the Gothic Revival style. The building was completed in 1912 with additions built in 1958. The original portion of the building was designed by architect Edward Ellsworth Hendrickson of the Frank Miles Day firm in Philadelphia. The building features a stone foundation, arched stained-glass windows, engaged buttresses, parapet walls, and a grand tower. The interior is characterized by dark-stained woodwork, decorative beams with carved dentils, and original oak pews. Stained-glass windows designed by the prominent Charles Connick Studio of Boston were added beginning in 1958. Connick was a well-known and prolific designer of stained-glass, however, St. Peter’s is one of only three churches in the State of Wyoming known to contain windows produced in his studio.

Located among other false front buildings along Main Street in Dayton, the Susan Wissler house is a frame, false front structure constructed as a commercial building in 1885. The traditional storefront design is typical of late nineteenth and early twentieth century commercial architecture. In 1911 Susan Wissler was elected mayor of the small ranching community of Dayton, thus becoming the first woman mayor in Wyoming, and one of the first in the United States. Wissler served three terms as mayor and made great strides toward improving the quality of life in the town. She lived in the house at 406 Main Street from 1905-1915, encompassing her years in office.

From the time the home was started in 1908, and July 16, 1913, when it was ready for occupancy, John B. Kendrick was on the fringe of a political career which took him to the Governor's office in 1914, and to the U.S. Senate in 1917. Trail End, which was built at a cost estimated at $160,000 including major furnishings, became a summer home due to Kendrick's political success. The architect for Trail End was William MacAlister of Billings, Montana, and the interior designer was another architect, D. Everett Waid of New York City. Good workmanship and the best materials were employed from foundation to roof and the result is a blending of beauty and sturdiness. The foundation is built of Indian limestone but everything above is brick, laid in a difficult old Flemish bond pattern. A dark mahogany woodwork is an interior feature, and 36 box cars of it were shipped from Grand Rapids, Michigan. The tile and marble throughout the house was made to order by a firm in Omaha, Nebraska. Ceilings and walls of the home not covered by paneling were covered with canvas and hand painted by a New York artist. The home is an outstanding example of many other homes built between 1880 and 1910 by cattlemen in the developing towns and cities of the high plains and mountain states. Today Trail End is a State Historic Site.