U.S. 310

U.S. 310 is a short U.S. highway that connects U.S. 14-16-20 northwest of Greybull with Business Loop I-90 (former U.S. 10) in Laurel, Montana. The southern terminus may have been relocated north and west to the point where U.S. 310 breaks off from U.S. 14-16-20. U.S. 310 does not extend south of the U.S. 14-16-20 intersection near Greybull. For its entire route within Wyoming, U.S. 310 shares alignment with Wyoming 789 and State Control Route 32: from U.S. 14-16-20 to the Montana State Line. Now that U.S. 10 is decommissioned west of Fargo, North Dakota, U.S. 310 is orphaned from its parent route.


Commissioned as one of the original U.S. routes in 1926, U.S. 310 has always maintained the same designation and routing since its inception. In 1954, it was cosigned with Wyoming 789.

U.S. 310 is the only indication left that U.S. 10 used to travel through Montana, the same way U.S. 199 reminds us that U.S. 99 used to run through Northern California or U.S. 138 in Colorado tells us that U.S. 38 used to travel from Greeley to Omaha.


U.S. 310 connects Greybull with Lovell and Frannie. This route roughly follows the Bighorn River, then angles northwest toward Montana. The highway is cosigned with Wyoming 789, and Wyoming 789 terminates at the Montana State Line.

U.S. 310/Wyoming 789 north
Northbound U.S. 310 and Wyoming 789 shield assembly. Wyoming has chosen to sign U.S. 310 as an east-west route, but it mostly leads north into Montana. The DOT has a similar issue with how it signs Wyoming 120 north/westbound. Photos taken by Jonathan Winkler, 8/00.
Alternate U.S. 14 west and U.S. 310/Wyoming 789 north
After a brief shared alignment west of Lovell, U.S. 310/Wyoming 789 north and Alternate U.S. 14 west split. From here, U.S. 310 and Wyoming 789 travel north to Frannie, Wyoming. After crossing the Wyoming-Montana State Line, U.S. 310 travels northwest to Laurel, Montana, where it ends at Business Loop I-90. Photo taken by Alfred Regnery (07/27/07).

Page Updated November 27, 2007.

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