In 1838, when the United States and the Republic of Texas surveyed the boundary between the countries along the Index Line (today's straight line from ca. Logansport, LA to the Arkansas/Texas border at the Red River), the surveyors noted features where they placed their markers. Between the Sulphur River and the Big Baoyou, they noted "Trammel's Trace to Fulton," (Hempstead County, Arkansas).
Trammel's Trace is an early 19th century path through southwestern Arkansas and northeastern Texas, between the Red and Sabine rivers, that was forged by Nicholas Trammell, a human enslaver and trafficker, horse trader, horse racer, and some say, a horse thief. For some reason, chroniclers spelled the road as "Trammel," possibly because it was too much trouble to add the second L.
Due to the length of the boundary but the need to print the information on the sizes of paper available at the time, the map is divided into three columns - south, middle, north - to mark the Index line.
You can enjoy this map in full at https://texashistory.unt.edu/ark:/67531/metapth493036/?q=texas
There are many mounds still along the Red north of Texarkana, tho not as many as once was. Many have been plowed away or nearly so, other than the sites now protected etc. Below is Battle Mound, it is east of the Red, just south of where US 82 crosses it, is the biggest Caddo mound.