Fjords are created when a rising sea ﬂoods a glaciated coastal valley. A fjord (sometimes spelled ﬁord and also known as a sea loch) begins as a U-shaped trough up to a hundred miles or more in length, gouged out by an advancing glacier plowing debris ahead of it. At its furthest reach, the glacier’s snout ﬂoats on a frozen or open sea. When the glacier retreats, it leaves behind a line of glacial debris—a terminal moraine, which later becomes an underwater sill near the fjord’s entrance. Multiple sills mark the temporary stopping points of some glaciers. When a rising sea enters these gouged troughs, it eventually forms long, ﬁnger-shaped, steep-sided inlets, commonly over a thousand feet deep. In many fjords, niche or cirque glaciers still hang from the mountainsides, ghosts of the fjord’s Pleistocene past. In summer, multiple waterfalls may spill down a fjord’s sides from these glaciers, the thin streams spiraling away in mist. In certain fjords, the parent glacier might survive still, as a tidewater glacier at the head of the inlet, where it now calves centuries-old ice that is still advancing seaward from the land’s interior. College Fiord and Chatham Strait in Alaska are among North America’s many fjords. In The Blue Bear, Lynn Schooler writes that the Hoonah Tlingit, who call Glacier Bay, Alaska, their traditional home, say “a foolish woman insulted the glacier and caused it to rampage down from the mountains. . . . Since then, the ice has been placated and withdrawn, grumbling and complaining, more than sixty-ﬁve miles back into the mountains,” creating in its wake the fjords of Glacier Bay National Park. The Norwegian word fjord came into English usage in 1674 when the Norse volume Scheffere’s Lapland was translated.