The rocks were the prototype of the temple, as was the forest of the Gothic cathedral, the date-palm of the Byzantine dome. But there worships here only the cañon-wren. He is the high priest who lifts up his voice in these rock temples--a sweet utterance delivered with the usual abandon of the wrens. Above the cliffs, on the precipitous slopes, is the impress of still another agent. The ledge, smoothed as by a plane, and the scattered boulders amidst the dead timber and small aspens, give it an appearance of extreme desolation. Here, where now the Indian paint-brush glows in summer, the glacier crept snail-like down the mountain, from its cradle in some _cirque_ above the forest. Timber-line is the frontier, the boundary between the verdant world and the land of snow and ice. It was the glaciers which in the days of their strength chiseled the lake basins every one, and began the great cañons on which the streams have been at work ever since. At the same time they laid out the _moraines_, like so many parks, where the pines and the spruce have planted themselves. They did the rough work and prepared the great rock masses for the finer work of the rain and frost and wind--as the stone-cutter precedes the sculptor. These lakes in many cases became the glacial meadows of today, which are like jewels set in the vast matrix of rock. Out of elemental changes, terrible in their immensity, came some of the most charming of all wild gardens,--as a rainbow follows a thunder-storm. These serene and altogether beautiful aspects of Nature were the outcome of tumult and passion--earthquakes, avalanches, lava-flows, glaciers, and now these idyllic meadows, beloved of bees and blossoms. There is a certain cañon hereabout which is closed abruptly at one end by a precipice, over which descends a considerable stream. This fall is a thing of beauty, and so holds the eye that few think of scaling the cliffs to see what may be beyond. But, as it happens, there lies above, and sundered from the world beneath, one of the most delightful little valleys in the Rockies--a long, narrow defile, flanked by perpendicular cliffs of pink and red and buff sandstone.