“About the centre of the flume, on the eastern side, and 30 feet from it, is the entrance to the Mill Bridge series of the caves, shown on the map as ‘Entrance No. 1.’ This entrance is a mere cleft in the rock strata, and is only wide enough to admit of the passage of a man’s body. The total length of the underground passageway, at one time accommodating a very considerable volume of water, is 400 feet. The height varies from a minimum of 10 feet to a maximum of 25 feet, and the width from 3 to 15 feet. At its eastern end it opens to an irregularly-shaped chamber of approximately 60 by 70 feet, with a greatest height of 20 feet. This chamber has been named ‘The Auditorium’ by the first exploring party. Cougar creek in its flow beneath Mill bridge passes through the Auditorium, and as it falls 75 feet in a distance of 200 feet, from its entrance beneath Mill bridge to the Auditorium, the chamber is replete with its roar, and the name is appropriate, though hardly in the conventional sense of the word. Faint daylight enters through the passageway of the waters and serves to make the surroundings look dim and mysterious. The frosts of winter also reach this spot, and in the spring stalactites and stalagmites, formed of huge icicles, are seen in columnar groups surrounding the dashing waters and extending some distance into the chamber itself. In this particular spot disintegration has created much havoc and the walls no longer show the marks of water erosion, while the floor is heaped with rock debris fallen from the ceiling. The passageway, however, that connects it with the surface is still intact as a sample of the power of water erosion. It is composed of a series of potholes, connected one with the other by short narrow passages. The bottom of each succeeding pothole, as you recede from the entrance, is at a lower elevation, sometimes as much as ten or fifteen feet. To make access possible, Deutschman has, with the assistance of a bridge carpenter loaned by T. Kilpatrick, superintendent of the Canadian Pacific Railway Company at Revelstoke, placed rough ladders from floor to floor. Most of these potholes hold water in the hollows at the bottom, and, in one case, the water is so deep—4 or 5 feet—and the potholes so wide that a floating bridge had to be built. When it is realized that every bit of timber used in these constructions had to be hewn from the tree and transported on the shoulder or back, over a road hardly accessible for a mountain goat, to the place where it was utilized, some idea of the magnitude of the work can be formed.