The western terminus of the highway is at its intersection with SR 33 at Wren, an unincorporated community in Lawrence County.

The eastern terminus of the highway is at its intersection with U.S. Route 231 (US 231) at Lacey’s Spring in Morgan County.

It crosses the two roadways of the road (AL-157 is a four-lane divided highway) and s-bends again.

It junctions with CR-72 (Iron Man Road) and continues onward to U.S. 31 in Hartselle.

Past this point, the route is in almost a completely straight line.