“On leaving the lake-bed above mentioned, Cougar creek flows in a series of cascades for a little more than half a mile through open alpine meadowland, broken here and there by knolls crowned with scrubby spruce. Suddenly, without warning, it drops into a cavity and, 450 feet farther down, quietly issues from its underground way. During this disappearance the stream has only dropped 30 feet. The intervening space between the entry into and exit from the ground has been named ‘Gopher Bridge’ by the first party visiting the Caves, owing to the large numbers of Parry’s marmot, which much resembles a gopher, to be seen in the immediate vicinity, and the underlying passages are here referred to as the Gopher Bridge series. Directly opposite the disappearance of the creek, two striking cascades tumble down the mountain side and uniting, flow for a short space parallel to Cougar creek; then, vanishing into a hole in the ground, they join the main stream by a subterranean passage. They are known as ‘Gopher Falls,’ and the place where they disappear as the ‘Gopher Hole’ (see map of Caves). “The Gopher Bridge series of passageways was at first entered by the opening shown on the map as ‘Old Entrance.’ It was a very disagreeable operation, entailing much wriggling and squeezing through narrow cracks over dirty rocks. Eventually, a point of vantage was reached directly over the subterranean torrent. At the time of the first exploration the writer took acetylene bicycle lamps, whose bull’s-eyes enabled the pitch darkness to be pierced to some extent. Magnesium wire also was lighted, and, by its aid, for a brief minute, the interior was bathed in dazzling brightness. Standing on a narrow ledge that overhangs a black abyss, the eye is first drawn by a subterranean waterfall heard roaring immediately on the left. It appears to pour from a dark opening above it. Below, between black walls of rock, may be seen the foam-flecked torrent hurtling down the incline until lost in sense shadows. Overhead, fantastic spurs and shapes reach out into the blackness and the entire surroundings are so weird and uncanny that it is easy to imagine Dante seated upon one of these spurs deriving impressions for his inferno. As the brilliant light goes out the thick darkness makes itself felt, and instinctively you feel to see if Charon is not standing beside you. This subterranean stream, with its unearthly surroundings, is somewhat suggestive of the Styx, and incidentally supplied the name ‘Avernus’ for the cavern of the waterfall.