LA 3136 begins at an intersection with LA 34, just north of the small town of Atlanta. LA 3136 ends at Parish Road 817, also known as the Packton Alexandria Road. PR 817 is a remnant road from when LA 500 ended at LA 34, then US 167. US 167 has been shifted east, and LA 500 now ends at this alignment.
LA 3136 is an undivided, two-lane road for its entire route.