US 431 enters the state going out of Robertson County, Tennessee, and into Logan County south of Adairville. It goes northward to Russellville, where it makes a left turn onto the Russellville Bypass, and follows it to the north side of town. It becomes known as the Terry Wilcut Highway from Russellville to Lewisburg.[3]
Confluence of the Green and Rough Rivers at Livermore.
For a unique reason, the U.S. 431 crossing of the Green River and Rough Rivers in McLean County, Kentucky, is a famous river crossing. It is at that crossing in the city of Livermore that U.S. 431 crosses two rivers and also crosses into Ohio County before completing the river crossing back in McLean County. This is the only known crossing of this type in the United States: a road starts in one county, crosses two separate rivers, crosses a sliver of land within another county, and then terminates the bridge crossing in the original county it started in. This special feature is marked by a state historical marker on both approach ends of the bridge.
In 1953, US 431 was extended into Tennessee and Kentucky from the Huntsville, Alabama area. From 1929 until sometime in the 1940s, the US 431 corridor in Kentucky was originally signed as Kentucky Routes 75 and 81. KY 75 ran from Owensboro to KY 81 at South Carrollton, while KY 81 ran its current course, plus the rest of US 431's original route from South Carrollton into Central City and Russellville to the Tennessee state line.[6] Sometime in the 1940s, KY 75 was extended southward from South Carrollton to the Tennessee State line near Adairville via Central City and Russellville.
In downtown Owensboro, KY 75 also ran onto the bridge connecting to what was originally a part of SR 75 (this stretch of roadway north of the bridge is now the present day SR 161) in Spencer County, Indiana until 1954, when US 231 was extended into Indiana.
Reroutings
US 431's original alignment in the city of Russellville became Kentucky Route 3519 in the mid-2000s, when the main US 431 alignment was rerouted onto the Russellville Bypass on the west side of town. As of mid-2010, Frederica Street in Owensboro no longer carries the US 431 designation into downtown Owensboro as KY 2831 is assigned onto that street.
In 2011, the US 431 alignment in Central City was rerouted onto the former KY 189 bypass on the west side of that city. This was done due to the low clearance of a bridge carrying the Paducah and Louisville Railroad tracks. US 431's original alignment in downtown is now designated as Kentucky Route 1031.
Northern terminus
In Owensboro, US 431 previously ended at a two-way pair junction with the original downtown alignment of US 60.[7] US 431's northern terminus was truncated to the junction with the US 60 Bypass in early 2011. The alignment from the bypass to the KY 54/KY 81 junction is now signed as KY 2831.
US 431 / SR 65 at the Tennessee state line
US 60 at Owensboro
