Louisiana Highway 840-1 (LA 840-1) spans 1.23 miles (1.98 km) from west to east and is known as Smith Street.

From the west, LA 840-6 begins as a state highway at an intersection with US 80/US 165 Business in Monroe.

Forsythe Avenue has many upscale shops and restaurants and is one of the prized thoroughfares through Monroe.

It connected US 165 Business to Vernon Street, providing access to the Louisiana Institute for Boys and E.A.

It spanned 0.74 miles (1.19 km) from west to east and is currently known as Desiard Street.

It connected downtown Monroe to US 165, but was eventually truncated before the 1955 Louisiana Highway renumbering to 26th Street.