It is time to pass from quadrupeds to bipeds. While our feathered friends were not so abundant in the wilder regions as we might have wished, still we had almost constant avian companionship along the way. The warbling vireos were especially plentiful, and in full tune, making a silvery trail of song beside the dusty road. We had them at our elbow as far as Graymont, where we made a sharp detour from the open valley, and clambered along a steep mountain side, with a deep, wooded gorge below us. Here the vireos suddenly decided that they could escort us no farther, as they had no taste for crepuscular cañons and alpine heights. Not a vireo was seen above Graymont, which has an altitude of nearly ten thousand feet. We left them singing in the valley as we turned from it, and did not hear them again until we came back to Graymont. Almost the same may be said of the broad-tailed humming-birds, whose insect-like buzzing we heard at frequent intervals along the route to a shoulder of the mountain a little above Graymont, when it suddenly ceased and was heard no more until we returned to the same spot a few days later. House-wrens, willow thrushes, Brewer's blackbirds, and long-crested jays were also last seen at Graymont, which seemed to be a kind of territorial limit for a number of species. However, several species--as species, of course, not as individuals--convoyed us all the way from Georgetown to the timber-line and, in some instances, beyond. Let me call the roll of these faithful "steadies": Mountain hermit thrushes, gray-headed juncos, red-shafted flickers, pine siskins, western robins, Audubon's and Wilson's warblers, mountain bluebirds and white-crowned sparrows. Of course, it must be borne in mind that these birds were not seen everywhere along the upward journey, simply in their favorite habitats. The deep, pine-shadowed gorges were avoided by the warblers and white-crowned sparrows, whilst every open, sunlit, and bushy spot or bosky glen was enlivened by a contingent of these merry minnesingers. One little bird added to our list in the gorge above Graymont was the mountain chickadee, which was found thereafter up to the timber-line.