Improving the River

East Dubuque Local Area History Project

Snag boat	A.D. 4/28/00

	The boat travelers often had trouble with the river. If the river gets too shallow the bottom of boats would hit. There might be obstacles like trees, rocks, and sandbars. The upper Mississippi had a lot of hazards. Many things have been done to improve the river. The Army Corps of Engineers has been in charge since 1830.

	Snags are floating trees on the river. Snag boats were used for taking objects like trees and logs out of the river. Snag boat were invented by a man named Shreve. They had two hulls, and a winch to help clear the jams.

Wing dams	In 1878, Congress approved a 4.5 foot channel from St. Paul to St. Louis. They did what they could do for that time. Sometimes they used blasting to clear the channel. The biggest problems were the Rock Island and Keokuk rapids. They also used wing dams. They are built of layers of crushed rock and willow mats. They send the flow of water to the middle and make a stronger current. They tried to keep the channel no more than 1,200 feet wide. Wing dams stick out from the side banks into the river. The wing dams helped, but there was still trouble at Rock Island, Keokuk, and also at St. Paul because of the rocks and rapids.

	The first locks and dams were built at St. Paul to pass St. Anthony Falls, and at Rock Island. These were completed by 1907.

	In 1907 the Congress approved a 6 foot channel. They had to do a lot of dredging to clear the channel. They also needed to build more wing dams. They also built more lock and dams. One of the biggest locks was in St. Paul. It was built in 1917, replacing the previous dam. There was also a lock built at Keokuk and Des Moines River rapids in 1913. The lock and dam at the Moline Rock Island rapids opened in 1924.

The Wm M Black, a dredger at the Dubuque River Museum	A dredge boat is one of the most important tools to keep the channel clear. They move slowly, possibly 200 feet a day. They have to work 24 hours a day. Under the water is a big dredge shed, about 34 ft wide on the bottom that shoots high power jets of water into the river bottom, then sucks out the mud and sand like a big vacuum cleaner. The boats have a big blade and pump as big as a room to create the suction. Those things deposit on the shore line through big 36 inch pipes that are 50 feet long on floats. Every day, they can pick up as much mud as the size of a football field four stories high, about 80,000 cubic yards.

	The Army Corps of Engineers also built a lock and dam in Galena River which had silted in. It opened in 1894. It was used until 1921, and removed in 1925.

	The 9 ft channel project was started in 1930. The Army Corps of Engineers built a full system of locks and dams, from Minneapolis to St. Louis. There were 24 locks and dams in all.

	The Army Corps of Engineers does a very good job of keeping the river clean. It is important for them do keep a clear channel for the barges and other boats to be able to haul freight on the river.

	Bibliography Field trip to Dubuque River Museum, 3/10/00. Larson, Ron. Upper Mississippi River History: Fact -- Fiction -- Legend. Winona, Minnesota: Steamboat Press, 1994. Photos Courtesy of Center for Dubuque History. Loras College, Dubuque, Iowa.