Wyoming Highway 585 starts it south end at US 85 in Four Corners, and from there, travels north-northwest through the northeastern corner of Weston County and into Crook County. WYO 585 has an interchange with Interstate 90 (Exit 187) at 27.41 miles (44.11 km) in Sundance. WYO 585 ends a half mile later at I-90 Business/US 14 (Cleveland Street).
Wyoming Highway 585 was commissioned in 1933 and has kept its original alignment since then. In 1933, US 85 had four US auxiliary routes: US 185, US 285, US 385, and US 485. It was possible that planners wanted WYO 585 to be made into US 585, however, that never happened.