The Lower Mississippi River Water Trail

Atchafalaya Upper

Mileage Down Lower Old River Channel

Note: The following numbers 0 to 6.9 refers to the mileage down the Old RIver Channel to reach the Three Rivers Junction, where the Red River comes in from the north and forms the beginning of the Atchafalaya River.  RBD = right bank descending, LBD = left bank descending, as if you are “descending” the channel from the Mississippi to the Atchafalaya (even though there is no flow).  If there is no designation the described feature covers the whole channel (i.e. a bridge, or the lock & dam).


0 Old River Channel


.5 RBD Commercial Bay - Lower Old River Channel


.5 LBD Enter Navigation Channel


.6 RBD Commercial Bay Boat Ramp


.6 Lock & Dam Bay


1.0 LBD Old River Lock Forebay


1.1 Inflow Landing Boat Ramp


1.0 East Lock Wall


1.0 - 1.3 Lock Chamber


1.3 West Lock Wall


1.5 LBD Old River Lock Tailbay


1.6 Outflow Landing Boat Ramp


2.8 LBD Exit Navigation Channel


2.9 RBD Lower Old River Channel


4.6 LBD Pointe Coupee Parish Port Dock


4.7 LBD Pointe Coupee Parish Boat Ramp


5.2 LBD Bayou Moreau


6.0 Barbre Landing


6.2 River Gage: Atchafalaya River at Barbre Landing


6.9 RBD Three Rivers Junction

The Red River flows in from the north and together with water drawn off the Mississippi  forms the beginning of the Atchafalaya River.   The Red and the Mississippi meet four miles upstream.  As you know, there is no flow through the Lower Old River Channel you just paddled.  The Mississippi River water was already added upstream through the various channels Inflowing from the control structures.  Approximately one third of the daily average flow of the Mississippi is to be kept flowing down the Atchafalaya.  That figure 30% is a Congressional mandate.  The Red River flow is augmented by the Old River Control structures which are opened or closed according to need to augment the flow of the Red and maintain the 30% flow.


In the late 19th and early 20th centuries, huge floods along the Mississippi River increased the size of the channel and the carrying capacity of the Atchafalaya River until concern mounted that it might capture most of the flow and redirect the Mississippi again. Congress directed the US Army Corps of Engineers to build a control structure that would allow restriction of the flow down the Atchafalaya River to 30% of the total flow down the Mississippi and the Red Rivers. The 70-30 split, as it came to be known, was approximately the breakdown of the flow in the 1950s and was thought to be a reasonable choice that would allow the Mississippi River to maintain its current route. The Corps completed the first elements of the control apparatus in the 1960’s.  (Friends of the Atchafalaya)

Red River

The Red River begins in New Mexico...

Three Rivers WMA and Red River NWR

From the top of Palmetto island down to Shreve’s Bar the sprawling Three Rivers Wildlife Managment Area (WMA) and Red River National Wildlife Refuge (NWR)

create sprawling swaths of deep bottomland hardwood forests, tupelo gum wetlands, and countless lakes, bayous and other waterways, bounded between the Mississippi and the Red River.   When viewed from above, this is one of the most extensive green areas on the entire Lower Mississippi, ranking alongside the White River WMA at the close confluences of the White-Arkansas-Mississippi River systems.  Only the Mighty Atchafalaya River Basin creates a bigger green space.


Red River NWR is a critical stop over point for migratory birds and provides crucial wintering grounds for waterfowl and wading birds. Over 80,000 waterfowl utilize the refuge for feeding and resting annually and over 200 species of neo-tropical migratory song birds seek refuge here.   Habitat types include shrub/scrub, open grassland, cypress sloughs, sandbars, various stages of reforested agriculture lands, batture and bottomland hardwood forest and moist soil impoundments. The refuge also has numerous oxbow lakes, bayous, rivers, irrigation ditches and reservoirs. With such a diverse array of habitats, Red River NWR supports an abundance of wildlife including over 44 species of mammals, more than 70 species of reptiles and amphibians, over 106 fish species, more than 200 species of migratory birds, 25 species of waterfowl and an array of plant life. Priority species for conservation found on the refuge include the cerulean warbler, Swainson’s warbler, the endangered least tern, the recently delisted bald eagle, the American alligator, alligator snapping turtle, rusty blackbird, Rafinesque’s big-eared bat, southern myotis bat and endangered pallid sturgeon.