The man was riding just below the summit of the ridge, occasionally uplifting his head so as to gaze across the crest, shading his eyes with one hand to thus better concentrate his vision. Both horse and rider plainly exhibited signs of weariness, but every movement of the latter showed ceaseless vigilance, his glance roaming the barren ridges, a brown Winchester lying cocked across the saddle pommel, his left hand taut on the rein. Yet the horse he bestrode scarcely required restraint, advancing slowly, with head hanging low, and only occasionally breaking into a brief trot under the impetus of the spur. The rider was a man approaching thirty, somewhat slender and long of limb, but possessing broad, squared shoulders above a deep chest, sitting the saddle easily in plainsman fashion, yet with an erectness of carriage which suggested military training. The face under the wide brim of the weather-worn slouch hat was clean-shaven, browned by sun and wind, and strongly marked, the chin slightly prominent, the mouth firm, the gray eyes full of character and daring. His dress was that of rough service, plain leather "chaps," showing marks of hard usage, a gray woolen shirt turned low at the neck, with a kerchief knotted loosely about the sinewy bronzed throat. At one hip dangled the holster of a "fortyfive," on the other hung a canvas-covered canteen. His was figure and face to be noted anywhere, a man from whom you would expect both thought and action, and one who seemed to exactly fit into his wild environment. Where he rode was the very western extreme of the prairie country, billowed like the sea, and from off the crest of its higher ridges, the wide level sweep of the plains was visible, extending like a vast brown ocean to the foothills of the far-away mountains. Yet the actual commencement of that drear, barren expanse was fully ten miles distant, while all about where he rode the conformation was irregular, comprising narrow valleys and swelling mounds, with here and there a sharp ravine, riven from the rock, and invisible until one drew up startled at its very brink. The general trend of depression was undoubtedly southward, leading toward the valley of the Arkansas, yet irregular ridges occasionally cut across, adding to the confusion. The entire surrounding landscape presented the same aspect, with no special object upon which the eye could rest for guidance-no tree, no upheaval of rock, no peculiarity of summit, no snake-like trail, -all about extended the same dull, dead monotony of brown, sun-baked hills, with slightly greener depressions lying between, interspersed by patches of sand or the white gleam of alkali. It was a dreary, deserted land, parched under the hot summer sun, brightened by no vegetation, excepting sparse bunches of buffalo grass or an occasional stunted sage bush, and disclosing nowhere slightest sign of human habitation