The word dalles is generally thought to derive from the French plural of dalle, meaning “gutter” or, possibly, “tube” or “conduit.” Dalle is also French for ﬂagstone, a natural material historically used to line gutters. Local history suggests that The Dalles, Oregon, a place where the Columbia River once moved swiftly between steep canyon walls, was named by French Canadian trappers: the steplike rapids created by the ﬂow of water over columnar basalt might well resemble water moving through an enormous gutter lined with ﬂagstone. The Grand Dalles refers to the great rapids east of the present town, which were inundated by the backwaters of the newly built Dalles dam in 1957, described by Robert Michael Pyle in Chasing Monarchs: Migrating with the Butterﬂies of Passage, this way: “It is now a prefab village above the reservoir beside the freeway, the home of those who remained after The Dalles Dam did its dirty work of drowning the falls, wrecking the ﬁshery, and killing what was left of the river culture in 1956.” Indeed, Celilo Falls, also erased by the resulting slackwater, was one of the most important and sacred Indian ﬁsheries in North America. In some regions, dalles may also be synonymous with dells. In Wisconsin, the geologic feature called the Dells is a channel system cut into Cambrian sandstone, through which the Wisconsin River ﬂows. In fact, the ravine complex was originally called the Dalles.