From the south, LA 131 begins at an intersection with
LA 15 in
St. Genevieve. LA 15 parallels the
Mississippi River north through points such as Deer Park and, upon reaching the junction with LA 131, turns to the northwest toward
Ferriday. LA 131 proceeds straight ahead, curving eastward with the river through a rural area toward
Vidalia, the
parish seat of
Concordia Parish. After , LA 131 crosses the town limit and intersects
LA 3180 (J. Logan Sewell Drive), which connects with
US 84 and
US 425 on the west side of town. LA 131 enters Vidalia on Martin Luther King Avenue and curves to the northeast, passing through a largely residential area. After , the route ends at an intersection with US 84-425 (Carter Street), the main highway through Vidalia. The northern terminus of LA 131 is located from the foot of the
Mississippi River Bridge, which crosses the state line into
Natchez,
Mississippi. US 84 and US 425 run concurrently between Natchez and Ferriday, to the northwest. The average daily traffic volume in 2013 is reported as 3,400 for the majority of the route, with a slightly lower figure of 3,200 in Vidalia between Gillespie Street and the northern terminus. ==History==