Riverlorian.com

There are several Red Rivers in the United States and this one is known as "The Red River of the South". It is the Red River that the song "Red River Valley" was written for. Palo Duro Canyon (photo) is south of Amarillo Texas and the birthplace of the spring fed Red River.  In this arid land the river often dries up. 

The upper Red River is a saltwater river. The saltiness is caused by a natural phenomenon that dates back to ancient times. About 250 million years ago, an inland sea blanketed parts of what is now those states. As time passed, that sea evaporated, leaving salt deposits – mostly sodium chloride. Rock and silt eventually buried the deposits, but the salt continues to leach through natural seeps in tributaries above Lake Texoma. 

Its name comes from its color, which in turn comes from the fact that the river carries large quantities of red soil in flood periods. It is not always red, particularly in the lower sections. 

Map shows the path of the River River from Texas to Louisiana.  The total length of the river is 1,360 miles

The upper Red River Meanders through Texas before becoming the border between Texas and Oklahoma, then Texas and Arkansas before flowing completely in Louisiana. The river has changed courses many times since becoming a border between states. When this happens the state line remains where it is but the river may be totally in or out of a border state.

The south bank of the Red River formed part of the US–Mexico border from the Adams–Onís Treaty (in force 1821) until the Texas Annexation and the Treaty of Guadalupe Hidalgo.

As can be seen in the photo, when the upper Red River is low, it leaves salt deposits (and sand). When it is dried up, it can be dangerous to walk, due to quicksand from the water table below the surface.

The only boating that can be done in this part of the Red River is by canoe or kayak, and even those might need to be dragged through particularly shallow areas. It is a beautiful and remote area for adventuresome paddlers.

The huge Lake Texoma is formed by Denison Dam on the Red River.  The dam site is approximately five miles northwest of Denison, Texas.  The lake has a surface area of 74,686 acres.

The dam was completed in 1944 for flood control and hydro-electricity. It also provides recreational opportunities for boaters and fishermen. While boater cannot go below the dam and spillway without portaging, there are many miles of lake/river and shoreline above the dam. The lake straddles both states, hense the name.

The Red River has changed courses many times as can be seen in this photo. The yellow dotted line is the state line between Texas and Oklahoma that was originally established as the middle of the Red River. Since then the River has moved but the state lines remain where they were surveyed.

Many oxbow lakes are left where the river once flowed. Some are still connected to the river and some are disconnected. You can see that there are some signs (scars) of other course changes but those occurred before the Oklahoma and Texas state lines were established. (Click image to see enlargement)

There is usually enough water depth for power boaters to use the Red River at around Texarkana, near where the river becomes the border between Texas and Arkansas. 

Even with the controls at Lake Texoma, the Red River floods. The photo is flooding at Texarkana in 2015. The Red River flooded all the way down to and included the Atchafalaya River and on to Morgan City, Louisiana.

By the time that the Red River reaches Shreveport/Bossier City in Louisiana, it has grown into a major river. From this point and downriver, it is a navigable waterway with commercial traffic and perfectly suitable for any size pleasure craft for the 232 miles to the end of the river. It is maintained by the Army Corp of Engineers with five locks & dams, along with wing dikes to stabilize the channel and riverbank. There are currently two marinas with fuel on the Red River. One is a few miles below Shreveport and the other is near Natchitoches.

The Red River ends where the Atchafalaya River begins. The Old River Complex was created to control how much Mississippi River flow is allowed to flow into the Red/Atchafalaya Rivers. At one time the Red flowed into a bend on the Mississippi River and the Atchafalaya flowed out of the Mississippi River to the Gulf of Mexico from the same bend. 

Henry Shreve (of Shreveport fame) made a cutoff of that bend in 1831 for navigation purposes.

Eventually this caused a problem that was found in

1951. The Mississippi River was probable going to change course toward the Atchafalaya River and would be a disaster for the lower Mississiippi River. In the end the problem was solved (for now) by building structures that controls how much water flows from the Mississippi to the Atchafalaya. As for the Red River, it comes to an end and the Atchafalaya River begins at the point where the lower Old River channel, as can be seen in the graphic. This point is mile 0 of the Red River and mile 0 of the Atchafalaya River. Sound confusing? That is because the mile markers on the Red River go upriver and the mile markers on the Atchafalaya River go downriver. At the confluence of the Lower Old River, vessels have access to the Mississippi River from the Red/Atchafalaya River, using a Lock. For those going to the Gulf of Mexico, it leaves two choices. The Atchafalaya River is a much shorter route.