east-northeast, while US 43 and SR 13 head to the northeast. US 43 and SR 13 curve to the north and intersect SR 64. They continue to the north and east until they reach the Tennessee state line, where SR 13 ends. Tennessee US 43 enters Lawrence County and the city limits of Saint Joseph. The unsigned State Route 6 (SR 6) begins at the state line. In the main part of the city, US 43 begins an unsigned concurrency with SR 227 (Iron City Road). They curve to the northeast, leave Saint Joseph, and enter Loretto. There, SR 227 splits off to the southeast onto East Main Street. Then, US 43 intersects SR 98 (Rabbit Trail Road) in Leoma. It has an interchange with US 64 (unsigned SR 15; Lawrenceburg Highway) in Lawrenceburg. In downtown Lawrenceburg, US 43 intersects US 64 Bus. (Gaines Street). The highway briefly parallels the North Fork Buffalo River before beginning a curve to the north and crossing that river twice. Then, US 43 intersects SR 240 (Monument Road) and Spring Water Drive. In Maury County, US 43 intersects SR 20. It intersects the southern terminus of SR 243 (South Main Street) in Mount Pleasant. It travels on an overpass over Mt. Joy Road and some railroad tracks. US 43 bypasses downtown by traveling through the western part of the city. It intersects SR 166 (1st Avenue). Then, it has an interchange with SR 243, which also leads to the Maury County Airport. It has an interchange with US 412 (unsigned SR 99) and the western terminus of US 412 Bus. (Hampshire Pike) in Columbia. At this interchange, US 43 and US 412 travel concurrently to the north-northeast. At an interchange with SR 50 (Williamsport Pike), the concurrency briefly re-enters the city before leaving again. The concurrency curves to the east-southeast and has an interchange with SR 7 (Santa Fe Pike). Then, they intersect US 31 and US 412 Bus (Nashville Highway). Here, US 43 ends, US 412 continues to the east-southeast on Bear Creek Pike, and SR 6 turns onto US 31 north. History Prior to the completion of Corridor X in western Alabama, US 43 and US 278 shared a concurrency with US 78 between Guin and Hamilton. 1934 proposed expansion In 1934 as part of a proposal to eliminate the US 31W and US 31E spilt, US 43 was to be extended