"The following day we continued our march down the border of the Llano Estacado. Knowing that our Comanche guide was about as familiar with all those great plains as a landlord with his premises, I began to question him, as we traveled along, concerning the different streams which pierced them to the southward. Pointing in that direction, he said there passed a water-course, at the distance of a hard day's ride, which he designated as a Cañada or valley, in which there was always water to be found at occasional places, but that none flowed in its channel except during the rainy season. This cañada he described as having its origin in the Llano Estacado some fifty or sixty miles east of Rio Pecos, and about the same distance south of the route we came, and that its direction was a little south of east, passing to the southward of the northern portion of the Witchita mountains, known to Mexican Ciboleros and Comancheros as Sierra Jumanes. It was, therefore, evident that this was the principal northern branch of Red River. The False Washita, or Rio Negro, as the Mexicans call it, has its rise, as he assured me, between the Canadian and this cañada, at no great distance of the southeastward of where we were then traveling."