The western segment of the loop is named after General Walton Walker, who served and died in South Korea.

Starting in the east at I-30, Loop 12 goes north as Buckner Boulevard, following surface streets past White Rock Lake.

It is also the only portion that leaves the Dallas city limits, as it runs through the eastern portion of Irving between where the road crosses the Elm Fork of the Trinity River (northern boundary, just north of the former site of Texas Stadium) and where it crosses the West Fork of the Trinity River (southern boundary).

At the intersection with US 175 and Murdock Road, Loop 12 turns north again as Buckner Boulevard all the way back to I-30.

On October 6, 1943, Loop 12 was extended northward and eastward back to SH 114 at White Rock Lake.