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, [Pg212] as we travelled 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 {147} 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 travelling. On the 15th, our Comanche guide, being fearful lest we should find no water upon the plain, advised us to pursue a more northwardly course, so that, after a hard day's ride, we again descended the _ceja_ or brow of the Llano Estacado, into the undulating lands which border the Canadian; and, on the following day, we found ourselves upon the southern bank of that stream. Although, but a few days' travel above where we now were, the Canadian runs pent up in a narrow channel, scarcely four rods across, we here found it spread out to the width of from three to six hundred yards, and so full of sand-bars (only interspersed with narrow rills) as to present the appearance of a mere sandy valley instead of the bed of a river. In fact, during the driest seasons, the water wholly disappears in many places. Captain Boone, of the U. S. Dragoons, being upon an exploring expedition [Pg213] in the summer of 1843, came to the Canadian about the region of our western boundary, where he found the channel perfectly dry.[132] Notwithstanding {148} it presents the face of one of the greatest rivers of the west during freshets, yet even then it would not be navigable on account of its rapidity and shallowness. It would appear almost incredible to those unacquainted with the prairie streams, that a river of about 1500 miles in length, and whose head wears a cap of perennial snow (having its source in the Rocky Mountains), should scarcely be navigable, for even the smallest craft, over fifty miles above its mouth.