The following is a list of minor state highways in the U.S. state of Louisiana in the 650-699 range. Many of these routes were designated as farm-to-market (or Class "C") routes in the 1955 Louisiana Highway renumbering. The shorter routes in the list often serve as connectors between main highways or are pieces of state-maintained roadways left over from highway realignments. Others are simply state-maintained bridges over waterways or provide access to various La DOTD facilities.
The route initially heads west from a boat launch on Bayou Cut Off then turns north and crosses US 90 via an overpass. The freeway is accessed indirectly by the north service road. LA 652 zigzags west, then northwest along Bayou Folse, north across Bayou Cutoff, and finally northwest a short distance to an intersection with LA 182 just inside Raceland. LA 652 is an undivided two-lane highway for its entire length.
The route heads north from an intersection with Eagle Island Road, a local road, and crosses Bayou Du Mar. It then crosses US 90 via an overpass. The freeway is accessed indirectly by the north service road. LA 653 continues north to an intersection with LA 182 south of Raceland. It is an undivided two-lane highway for its entire length.
Until recently, LA 653 extended west from its current southern terminus along what is now a private road to a second intersection with LA 182, existing as a loop off of that highway. In this form, LA 653 was part of the original route of the Old Spanish Trail, designated as State Route 2 in 1921 (in the pre-1955 Louisiana Highway system) and US 90 in 1926. This route was bypassed in 1938 when US 90 was moved onto what is now LA 182. LA 182 was then bypassed by the current route of US 90 in 1977 (north of Exit 210) and 1997 (south of Exit 210).
The route heads northeast from LA 1 and immediately crosses a vertical lift bridge over Bayou Lafourche. It then intersects LA 308 which, like LA 1, follows alongside the bayou. 4.4 miles (7.1 km) later, LA 654 curves to the south and proceeds a short distance to a bridge at the Company Canal. A private road crosses the canal and proceeds toward the Golden Ranch Plantation in Gheens. LA 654 is an undivided two-lane highway for its entire length.
Louisiana Highway 657 (LA 657) runs 2.51 miles (4.04 km) in a north–south direction from LA 3235 in Larose to the end of state maintenance just north of Larose in Lafourche Parish.
The route heads northeast from LA 3235 and intersects LA 1, which follows the west bank of Bayou Lafourche. It proceeds immediately across a vertical lift bridge over the bayou and intersects LA 308. Here, LA 657 turns west alongside Bayou Lafourche while LA 308 continues straight ahead. Reaching the Gulf Intracoastal Waterway, LA 657 turns again to the northeast and crosses underneath LA 308. State maintenance ends just beyond Pump Station 7 Road, a local road. LA 657 is an undivided two-lane highway for its entire length.
The route heads east from LA 24, which changes from a divided four-lane highway flanking Bayou Terrebonne to an undivided two-lane highway running along the west bank of the bayou. LA 659 proceeds along the east bank and exits the city of Houma. After curving to the southeast, it intersects LA 3087 (Prospect Boulevard). The highway continues southeast to Presquille and a second intersection with LA 24, which crosses to the east bank of the bayou. LA 659 is an undivided two-lane highway for its entire length.
The route heads northeast from LA 24, which travels on either side of Bayou Terrebonne. It then curves to the southeast, running parallel to the limits of Bayou Cane and Houma. LA 660 intersects LA 182 and LA 3087, which connect Houma to eastbound US 90. The route ends at an intersection with LA 316 on the Terrebonne–Lafourche parish line. It is an undivided two-lane highway for its entire length.
The route heads northeast from an interchange with LA 315 (Bayou Dularge Road) and immediately crosses a swing bridge over the Houma Navigation Canal. It then crosses a vertical lift bridge over Bayou La Carpe and enters the city of Houma where it travels along South Van Avenue. In Houma, LA 661 intersects LA 57 (Grand Caillou Road) and LA 3040 (Tunnel Boulevard). Crossing LA 3040, the highway curves to the north as Howard Avenue and proceeds to LA 24 (Main Street) at Bayou Terrebonne. A locally maintained vertical lift bridge crosses the bayou and connects to LA 659 (Park Avenue), which follows the opposite bank. LA 661 is an undivided two-lane highway for its entire length.
Louisiana Highway 664 (LA 664) runs 0.82 miles (1.32 km) in a north–south direction along St. Charles Street in Houma, Terrebonne Parish.
The route begins at LA 311 (Little Bayou Black Drive) and proceeds north along the Houma–Bayou Cane line. Almost midway through its route, LA 664 intersects LA 3040 (Tunnel Boulevard), a four-lane highway that runs southeast to northwest through Houma and Bayou Cane. At the end of its route, LA 664 intersects eastbound LA 24 (Main Street), crosses a bridge over Bayou Terrebonne, and terminates at westbound LA 24 (Park Avenue). LA 664 is an undivided four-lane highway with center turning lane from LA 311 to LA 3040, after which point it narrows to an undivided two-lane highway for the remainder of its route.
Louisiana Highway 665 (LA 665) runs 9.88 miles (15.90 km) in a northwest to southeast direction from LA 55 in Montegut to a dead end at the Cutoff Canal southeast of Montegut, Terrebonne Parish.
The route initially heads northeast from LA 57 in an area known as Pointe Aux Chenes at the northern limit of Montegut. After 1.1 miles (1.8 km), LA 665 turns to the southeast to run alongside Bayou Pointe Au Chien. The highway continues for another 8.8 miles (14.2 km) to the Pointe Au Chien Landing at the Cutoff Canal. LA 665 is an undivided two-lane highway for its entire length.