First Dam on the Mississippi

Transportation | FIND Iowa
Apr 18, 2024 | 00:03:46

How did the Keokuk-Hamilton Lock and Dam benefit Iowans in the early 1900s?

Steamboats on the Mississippi River connected Iowa to other parts of the country, but not without challenges. Learn how engineers overcame problems faced by the Des Moines Rapids.


(Abby Brown, host of FIND Iowa, is standing on an elevated walkway with a river behind her.)

[Abby Brown] Transporting people and goods along the Mississippi River has been essential to the people that live here, even before Iowa was officially a state. Some parts of the mighty Mississippi were unsafe to travel, presenting some interesting challenges to overcome.

[Abby] This is Lock and Dam 19. It's located at the most southeastern tip of Iowa.

(A panoramic view of Lock and Dam 19. The dam, consisting of 119 rectangular sliding gates, stretches from the west bank of the river to the east side of the river where it connects to a Power Plant on the water. The lock is southeast of the Power Plant next to land. The lock is made up of two tall concrete walls on each side and a gate on the north and south ends, forming a rectangle. The river water fills the lock almost to the top of the walls. Past the south gate, the lock’s walls are half as tall and the water level is lower.)

[Abby] That little part of Iowa that dips down like that, giving our state a unique shape is actually part of this story.

(A map of Iowa shows how Lee County juts out like a big toe in the southeast section of the state.)

[Abby] It's where the Des Moines River and the Mississippi River meet.

(The Des Moines River and Mississippi River join in the shape of a “Y” to form the Des Moines River Confluence.)

[Abby] Near there, back when Iowa was first settled, that area presented a problem for river traveling. The problem was the Des Moines Rapids, a ten mile section of the Mississippi River that was rough and very shallow.

(A navigational map of the Des Moines River rapids, where the Des Moines River flows into the Mississippi River.)

[Abby] Because the Mississippi River got a lot wider just a few miles from here, the depth changed, going from 22 feet to just 2 1/2 feet. That's not deep enough for a big boat to get through. So until people engineered a solution, the Des Moines Rapids were a hard stop for big boats, at least without taking a really long time.

(A black and white photo of the building of Lock & Dam, Number 19. You can see on the right a wall section. The wall section has three tunnels built into the wall like a lowercase “m”. Several cranes have their booms up above the wall, like the booms were legs of a very large spider that was trying to climb the wall.)

[Abby] In 1913, the Keokuk-Hamilton Dam was the answer that finally fixed the Des Moines Rapids problem. It was the first dam on the Mississippi River, and it went all the way across.

(A modern, aerial photograph of the Keokuk-Hamilton Dam. You can see the tunnel section of the lock and dam on the left side of the photograph. The Keokuk Plant building is towards the center of the river, and there is a large walkway with tunnels underneath that spans from the center of the river to the right shore of the Mississippi River. The walkway looks like the spiral of a spiral notebook.)

(A black and white photo of two steamboats moving through the Keokuk-Hamilton Dam. The photo reads “1148- IOWA DIV - FIRST BOATS TO GO THRU NEW LOCK - TWO BOATS. JUNE 10, 1915.”)

[Abby] Cargo no longer needed to be unloaded before the rapids; put onto a horse and wagon; taken ten miles by land; and then loaded onto another boat.

(A pen and ink drawing of the Keokuk Rapids Canal. A steamboat is traveling through the canal.)

[Abby] This dam made history. And, it made travel on the mighty Mississippi a lot more efficient.

(A black and white photograph of the completed Keokuk-Hamilton Dam. The photograph reads “1181- IOWA-DIV-General View of Complete Lock Aug-21-1913.”)

(A modern photograph of the Keokuk-Hamilton Dam from the opposite side of the Mississippi River facing Keokuk, Iowa.)

[Abby] So, Kirk, how did travel change on the Mississippi with the addition of the Keokuk-Hamilton lock and dam?

[Kirk Brandenberger, Keokuk Area Convention and Tourism Bureau] Travel was very hard getting past Keokuk. And they had tried other things before, but they had this bright idea of combining a hydroelectric plant with a lock and dam. And the dam raised the river behind the you know, the dam and made it much easier to navigate past Keokuk.

[Abby] So Kirk, what is a lock and how does it work?

[Kirk] They bring a boat end to the lock and then they lock it in, basically closing off both sides, and then they pump water in. Raise the boat up to the level that is on the north side. And then they let the boat out. They open this one gate and let it out.

[Abby] And that's all because the dam is holding back so much water that the level in front of the dam and behind the dam is so much different.

[Kirk] That's right. And Keokuk, there's 38 feet from head water to tail water. So that much difference. They have to lower or raise the boat depending on the direction.

[Abby] The Mississippi River truly is mighty, and taming its rougher areas has really shaped our history.

(A black and white photo of the modern lock and dam at Keokuk, Iowa.)

[Announcer] Funding for FIND Iowa has been provided by The Coons Foundation, Pella, and the Gilchrist Foundation.