The Pecos at this point, and for many miles above and below, ran between low banks that rose vertically from the water. On both sides its "bottom" was a smooth plain, extending for miles back, where it stepped up to a higher level. It was nearly treeless. Scattered clumps grew at distant intervals, and along its margin a slight fringing of willows. This fringe was not continuous, but broken here and there by gaps, through which the water might be seen. The timber clumps were composed of cotton-wood trees and live-oak, with acacias forming an underwood, and occasionally plants of cactus growing near. These groves were so small, and so distant from each other, that they did not intercept the general view of the surface, and a person occupying one of them could see a horseman, or other large object, at a great distance. A man concealed in them could not have been approached by his enemy in daylight, if awake and watching. At night, of course, it was different, and the security then afforded depended upon the degree of darkness. The "motte" at which the cibolero had arrived was far apart from any of the others, and commanded a view of the river bottom on both sides for more than a mile's distance. The grove itself was but a few acres in size, but the fringe of willows running along the stream at both ends gave it, when viewed from a distance, the appearance of a wood of larger dimensions. It stood upon the very bank of the stream, and the selvedge of willows looked like its prolongation. These, however, reached but a few feet from the water's edge, while the grove timber ran out several hundred yards into the plain. About this grove there was a peculiarity. Its central part was not timbered, but open, and covered only with a smooth sward of gramma-grass. It was, in fact, a glade, nearly circular in shape, and about a hundred yards in diameter. On one side of this glade the river impinged, its bank being almost a tangent line to it. Here there was a gap in the timber, so that out of the glade could be obtained a view of the bottom on the other side of the stream. Diametrically opposite to this gap another opening, of an avenue-like form, led out into the adjacent plain, so that the grove was in reality bisected by an open line, which separated it into two groves, nearly equal in extent. This separation could only be observed from certain positions in the plain-- one on each side of the river.