What the River Carries

State Lines

The first bridge to connect Hamilton, Illinois, and Keokuk, Iowa, was a drawbridge that opened to wagon, buggy, and train traffic in 1871. Even though the placement of the piers and the nearby presence of the treacherous Des Moines Rapids made this, in the opinion of the U.S. Army Corps of Engineers, "the worst bridge for the passage of [lumber] rafts, and one of the worst for the passage of steamboats, on the Mississippi River," the bridge stood until 1915, when a new bridge was built on the old pillars.

Not long after the first bridge opened, a dispute arose between Iowa and Illinois as to how much each state could tax the owners of the bridge. Iowa claimed the right to tax to the middle of the river. Illinois claimed the right to tax to the navigation or commercial channel, which at that time and place ran closer to the Iowa than the Illinois bank. The Keokuk & Hamilton Bridge Company complained that because of these different opinions about the location of the state line, it was paying double taxes for 716 feet of the bridge. Was the border at the river's midpoint or at the thalweg, the part of the channel with the greatest depth and fastest flow? The answer to this question had far-reaching implications because nine other bridges spanned the Mississippi River between the two states.

In State of Iowa v. State of Illinois, 147 U.S. 1 (1893), the U. S. Supreme Court ruled that "all the recognized treatises on international law of modern times" identify "the middle of the channel of the stream" as "the true boundary between the adjoining States up to which each State will on its side exercise jurisdiction." When there were several channels, the boundary was to be drawn at the middle of the principal one. Between Keokuk and Hamilton, the steamboat channel was 880 feet from the Iowa shore and 2,162 feet from the Illinois shore, which meant that Illinois was justified in taxing most of the bridge. Yet, when Justice Stephen Field, who delivered the court's opinion, wrote that the navigational channel "varies from side to side of the river, sometimes being next to the Illinois shore and then next to the Iowa shore, and at most points in the river shifting from place to place as the sands of its bed are changed by the current of the water," he was telling the two parties that when the state line is drawn by water, it is a moving thing.

But shifts in the river channel are seldom followed by changes on the map or in jurisdiction. Until the mid-nineteenth century, the Mississippi made a sharp turn to the west and then the east at a point about halfway between St. Louis and Cape Girardeau. On the peninsula within the meander, land firmly attached to Illinois, French settlers built the town of Kaskaskia, which became a bustling commercial center and the capitol of the territory and later the state of Illinois. But in 1844, the river began shifting its course. During the Flood of 1881, the river abandoned its channel and captured the former valley of the Kaskaskia River. This cut off the big meander and turned the area into an island. Now, the terribly flood-prone Kaskaskia Island is separated from Missouri by what appears to be only a creek but is, in fact, the old river channel, and can be reached only by boat or a bridge from St. Mary, Missouri. The river's thalweg flows on the east instead of the west side of the island, making this soggy piece of land the only part of Illinois that lies west of the Mississippi.

Nonetheless, Illinois has fought and won numerous court battles with Missouri so that it can ignore where the river draws the line and keep the 2,300-acres of prime bottomland on its tax rolls.

Oxygen

Depending on where you live on the river, mayfly nymphs emerge from the water between April and August. They break the nymphal skin, unfurl elegant, many-veined, transparent wings...