Constructed in 1900, the Sweetwater Brewery is a historic building located in Green River, Wyoming. It was designed by German brewer Hugo Gaensslen, who arrived in Green River around 1891. Gaensslen was inspired by the Chicago water tower and designed the brewery to have several castle-like turrets on facade of the building. Beer is no longer made there, but a bar, Sweetwater Brewery, is housed in the building, which was placed on the National Register of Historic Places in 1982.
A few German brewers operated breweries on the site before Gaensslen. The first brewer, Adam Braum, opened his business in 1872. Gaensslen's business, called Green River Brewery, was successful until prohibition forced him to make non-alcoholic beer in 1919. He died in 1931, two years before prohibition ended. An Irish con-artist, Tom Flaherty, opened a brewery in 1936 but only wanted to make a quick profit and he fled to Canada soon after. He was the last person to make beer in the building. Several businesses have used it since then.