WYO 789 begins at the
Colorado state line just south of
Baggs. It travels north for about to Baggs. After Baggs, it continues north for about until it reaches the county line. After crossing the county line, WYO 789 travels north for about where it reaches exit 187 of
I-80/
US 30. WYO 789 joins I-80/US 30 eastbound. , May 2014 I-80/US 30/WYO 789 re-enter
Carbon County. Just west of
Rawlins, WYO 789 leaves at exit 211, joining
I-80 Bus./
US 30 Bus. through Rawlins. North of town, WYO 789 intersects
US 287 and travels concurrent with it north for to the county line, after which it passes through
Natrona County for about . US 287/WYO 789 continue in a northwest direction, passing through the towns of
Jeffrey City and
Sweetwater Station. About from Sweetwater Station, US 287/WYO 789 enter
Lander. WYO 789 splits from US 287 here and continues northeast for , alone, to
Riverton. WYO 789 joins
US 26 until they reach
Shoshoni. Here, US 26/WYO 789 intersect
US 20 where WYO 789 continues north with US 20 west. US 20/WYO 789 continue through the
Wind River Canyon into
Thermopolis. From there, the highway veers off in a northeasterly direction into
Washakie County. From the Washakie county line, the highway travels approximately before crossing the Big Horn River into
Worland where it joins
US 16/US 20. Upon crossing into Big Horn County, US 16/US 20/WYO 789 veer back to the northwest and cross back over the Big Horn River after reaching
Manderson. It continues on to the north through
Basin and
Greybull. Upon reaching Greybull, US 16/US 20/WYO 789 head west and join
US 14 for about . At that point, WYO 789 separates from the concurrency of US 14/US 16/US 20 and returns to its northern path along with
US 310 for about to the town of
Lovell. For about , US 310/WYO 789 travels west along
US 14 Alt. US 310/WYO 789 then turn north for about to
Cowley and then head west about to
Deaver. From Deaver, US 310/WYO 789 travel about north to
Frannie, where they straddle the boundary between
Big Horn County and
Park County. Just to the north of Frannie, US 310/WYO 789 bends slightly to the west, so that the road is actually inside Park County by about 400 feet before reaching the
Montana state line. At the state line, WYO 789 ends, while US 310 continues north. ==History==