During early planning of I-90, the town of
Clearmont (on US 14) filed suit against the
Wyoming Highway Commission for an alleged violation of a 1955 state law that required approval from voters for the construction of a
bypass. The town sought an
injunction to halt construction and reroute I-90 towards the town, which was north of the planned alignment, arguing it would be a straighter route between Sheridan and Gillette. Clearmont had previously been selected for a rerouting of US 14 and US 16 in 1957, which was seen as a precursor to a later Interstate Highway; the straighter route was also supported by business groups in Sheridan. The injunction was denied by a state district judge in 1959 and was appealed to the
Wyoming Supreme Court, which ruled in favor of the state highway commission in December 1960. Construction of I-90 in northwestern Wyoming began during the appeals process, with under active contracts for grading and site preparation by December 1960. The bypass of Sheridan, one of the first major sections of the freeway, was opened to traffic on July 28, 1962. The longest stretch, between Buffalo and Gillette, was dedicated on October 14, 1962, and cost $18.4 million to construct. It was initially a two-lane limited-access road that was later widened to four lanes. The final link in the section between Sheridan and Buffalo was opened in December 1968. The final Wyoming section of I-90 was opened to traffic on October 10, 1985, following four years of construction on between the Montana state border and Ranchester. It was also the final section of the Interstate Highway System to be completed in the state. ==Exit list==