Early writers in English referred to the “cataracts of heaven” to describe the floodgates through which rain poured for forty days and forty nights to produce the flood of Genesis, which only Noah and the passengers of his ark survived. Such cataracts were great waterfalls, and so the term was classically applied. By the nineteenth century, however, cataract had come to describe not a single waterfall but a series of them. In this usage, a cataract differs from a run of rapids only in the scale of its magnitude. John Wesley Powell, in his exploration of the Colorado River, applied the term enduringly to a stretch of the river in southeastern Utah. On July 23, 1869, he wrote in his journal: “We come at once to difficult rapids and falls, that in many places are more abrupt than in any of the canyons through which we have passed, and we decide to name this Cataract Canyon.” The following day he elaborated: “Large rocks have fallen from the walls—great, angular blocks, which have rolled down the talus and are strewn along the channel. . . . Among these rocks, in chutes, whirlpools, and great waves, with rushing breakers and foam, the water finds its way, still tumbling down.”

William deBuys