Since the 1955 renumbering, the route of LA 6 has seen no major alignment changes apart from its shift onto a bypass around Natchitoches around the 1990s. LA 1 and LA 6 originally followed their current business routes through town. In 1975, the Natchitoches Bypass (constructed as LA 3110) was opened, relocating LA 1 on its current route, looping around the south and west side of town. LA 1 Bus. and LA 3191 were created at this time to cover the original route. Around 1980, a road was constructed to connect LA 6 with the LA 1 bypass on the north side of town. It was originally designated as LA 3175 and became part of LA 6 by the mid-1990s. LA 6 then became concurrent with LA 1 running along Sibley Lake, and LA 6 Bus. was created along the original route through Natchitoches.