One of the least studied but apparently, major trade arteries emanating from the Red River was the so-called "Great Spanish Road" that originated near the confluence of the Washita and Red rivers (today's Bryan County, Oklahoma) and snaked through the prairies and plains northwest to Santa Fe, New Mexico.
Very few historical references exist about this trail. In 1925, Grant Foreman wrote that it was the "first known trail of any record" in today's Oklahoma, running from "Natchitoches to Nacogdoches to Santa Fe" through "Tillman, Beckham, and Greer Counties." John Melish's 1822 map seems to be the first to document the pathway. According to an 1896 Texas boundary study, Melish's map "was constructed from information derived from travelers along the old Spanish Road." John Arrowsmith copied the same road in the same location in a map from 1840. According to accounts by Captain Randolph B. Marcy, he followed "Mexican cart tracks" in the road to conduct immigrants from Fort Smith to Santa Fe in 1849. A counter point to the existence of this road is an 1847 map by John Disturnell, whose map was used by Mexico during the Mexican American War. Disturnell's map does not depict this road at all, which is odd considering that Mexico insisted that its claim to Texas extended all the way into today's Texas Panhandle.
So, did this road exist, or not? It's one of many Red River mysteries. The mystery isn't helped that its origin point lies now beneath Lake Texoma. But stay tuned! More evidence has been found... see the next post.
Disturnell's map, used by Mexico during the Mexican-American War, does not depict the Great Spanish Road at all. https://www.loc.gov/item/2004627240/
In 1822, John Melish depicts the Great Spanish Road as starting at the confluence of the Red and Washita (here, called the "False Washita") rivers. https://www.loc.gov/item/96686688/
John Arrowsmith's map copied Melish's map to depict the Great Spanish Road in 1840.