The river went on raising and raising for ten or twelve days, till at last it was over the banks. The water was three or four foot deep on the island in low places and on the Illinois bottom. On that side it was a good many miles wide; but on the Missouri side it was the same old distance across – a half a mile – because the Missouri shore was just a wall of high bluffs.
– Mark Twain
The Adventures of Huckleberry Finn, Chapter 9. Huck describing the Mississippi River in early summer, just after he and runaway slave Jim escape to Jackson Island.