I know nothing more about this site than what is on the plaque. The plaque is located in Falls Park, near the Horse Barn Art Museum (Google Maps link.)
Here is what it says:
The Dubuque House, Sioux Falls' first hotel, was built about 350 yards due wewst of this spot by Wilmot w. Brookings and members of the Western Town Company of Dubuque, Iowa, in September 1857. In the previous year, they had staked out a 320 acre claim and established the town of Sioux Falls, Minnesota Territory, on the west side of the Big Sioux River. The new town-site was northwest of a large wooded island, originally called Brookings but later renamed Seney.
Although Dubuque House was built for visitors and prospective settlers, it may have also served as a meeting hall, freight station and post office. It appears in the field notes and on the first map of Sioux Falls made by a federal surveyor in Augus, 1859, the only building shown within the town-site.
The primitive hotel was built of rough undressed blocks of Sioux Quartzite, found in the stone outcroppings which surround the Falls of the Big Sioux River. No photographs or sketches of the hotel are known to exist, but it was probably a rough rectangular-shaped structure featuring a single open room with a loft above and a cellar below. Sleeping accomodations were crude, with cloth sack mattresses filled with prairie grasses on rough wooden cots or on the floor, with animal skins and blankets for covers.
Since the settlers had a steam-driven saw mill, we can assume that the roof was probably made of rough boards and light wooden poles covered with thatch and dirt, much like settlers' cabins. Windows were small and covered with cloth or skins. Oil lamps provided any interior lighting. There probably was not an innkeeper in residence; whether visitors paid for sleeping space is uncertain. But the existence of the Dubuque House enabled the town promoters to assure the world that the new city did indeed have a new hotel!
With the rest of the town, Dubuque House was abandoned in the Dakota War of 1862 and probably burned by the Santee Sioux. When Fort Dakota, D.T., was established in 1865 at what is now the northeast corner of Phillips Avenue and Eighth Street, the Sioux Falls town-site was included within the boundaries of the 70 square-mile military reservation surrounding the Fort. Not until Fort Dakota was closed in 1869 was the military reservation reopened for civilian settlement. The remains of the Dubuque House were razed and the stones were probably used to begin the construction of teh Stevenson Hotel near the intersection of North Main Avenue and Falls Park Drive. Although that hotel's walls were erected, the building was never completed. However, in 1874, stone from the unfinished Stevenson Hotel was used nearby for the construction of the city's first brewery.
DEDICATED IN 1997 BY THE MINNEHAHA COUNTY AND SOUTH DAKOTA STATE HISTORICAL SOCIETIES, MINNEHAHA CENTURY FUND AND BLAKE LAW OFFICES