Four Mile Bridge
In April of 1927 Charles M. Smith, of Thermopolis, was awarded a construction contract for Four Mile Bridge under Federal Aid Project 90. 2.9 miles south of Thermopolis. [ As near as I can tell from looking at Google Earth Satellite images the bridge is no longer there. ]
The bridge is a single span seven panel Pennsylvania Trough Truss with substruts. This type construction is rare in road bridges. Ususally used for railroad bridges. The bridge has an overall length of 195 feet and a center span of 175 feet with a roadbed of 20 feet width.
In 1981 it was said that this was one of only two bridges of it's type still functioning in Wyoming. Also, "one of Wyomings more significant trusses."