The Boston-Wyoming Smelter site is a specific point of interest relative to the Grand Encampment Mining District. The smelter property is only the site of the former smelter, since all of the buildings which were once on the site have been destroyed or removed, leaving only the foundations and traces of walls as evidence of the smelter's former expansiveness.

The era of the Grand Encampment district began in 1897. In that year Ed Haggarty, a prospector from Whitehaven, England, discovered a rich copper prospect which he named the Rudefeha. Much of the more than two million dollars of copper from this area of Wyoming came from this one great prospect and mine. Seeking capital and the development of the region was the foremost advocate or promoter of the Grand Encampment Mining Region, Willis George Emerson. By 1902 the construction of a smelter at Encampment had been accomplished, largely through the efforts of promoter Emerson, and was listed under the name of the Boston and Wyoming Smelter. It was built adjacent to the town on the west bank of the Encampment River to serve mainly the Ferris-Haggarty mine. It contained, with later additions, the equipment necessary to transform copper ore to consumable metal.

By 1904 the mining operations were at their apex, employing 200 men and producing over $1,400,000 worth of copper. Although the price of copper increased to its highest ever at 26 cents a pound in 1907, the Grand Encampment area would not become a part of that copper prosperity. The Grand Encampment copper region epitomizes the ''boom and bust'' syndrome of many Western mining areas. The reasons for the collapse of the boom in the region are many. Foreclosure proceedings began in 1913 and salvage operations followed shortly.

The Willis House is a two-story modified American Four Square style house built in 1908. It is the only two-story masonry clad residential building in the town of Encampment. The house was built by Mrs. Lydia M. Willis to be a deluxe house of prostitution and the headquarters of the Willis business empire. Mrs. Willis never finished the inside of the house. In 1931, the house was acquired and finished by Mr. Charles Deo Terwilliger, a locally prominent and respected rancher and merchant.