1935 Mississippi Lock and Dam #20 near Canton, MO

(John A. Weeks III; HAER; Satellite)

USACE_instructions

"The maximum lift is 10.5 feet with an average lift of 5.3 feet....The movable dam has three non-submersible roller gates (20 feet high by 60 feet long), 34 non-submersible Tainter [Parker] gates (20 feet high by 40 feet long), and six submersible Tainter gates (20 feet high by 40 feet long). The submersible Tainter gates submerge three feet." [USACE]

USACE, Rock Island District posted two photos with the comment:

Today we have another 'Then & Now'! This one takes us down to Lock and Dam 20 in Canton, Missouri. The first photo was taken in July of 1935 and shows construction of the steel forms that would later make up piers 8 and 9 of the dam.

The second photo was taken earlier this month [Oct 2024] and shows what the completed dam looks like today. Both photos were taken looking west towards the lock.

USACE, Rock Island District posted these two photos again with the comment:

Today [Jun 9, 2025] we wish a "Happy Birthday" to Lock and Dam 20 in Canton, Missouri! On this date in 1936, Lock and Dam 20 on the Mississippi River opened for operation. As only the second lock to go into operation on the Mississippi River within the Rock Island District, LD20 has been helping commercial traffic navigate the river for 89 years!

Robbie Quiller-Tallent: You used to be able to get so close that you could talk to the deckhands while they locked through.

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USACE, Rock Island District posted
Today's [Sep 26] #FlashbackFriday takes a look at Lock and Dam 20 in Canton, Missouri! This photo shows construction of the dam in 1934. Construction was completed the next year with operation beginning in June 1936. The site has been helping aid with navigation along the Mississippi River ever since!

USACE, Rock Island District posted

This week's #FlashbackFriday takes us to Lock and Dam 20 near Canton, Missouri. This photo, taken in 1934, shows the dam being built.

Today, an average of 21.7 million tons of cargo passes through Lock and Dam 20 annually. A majority of that cargo is food and farm products, but can you take a guess at what percentage of the 21.7 million tons falls into that category? Let us know in the comments below!

Jason Herr: 93%?

Note the high river level. All of the gates are out of the water. There was flooding on the Mississippi in 2024. Some of the locks closed in July.

Street View, Jun 2024

In the only other comparable view available, we can't see the river level.

Street View, Jul 2012

And then it occured to me that I could get a different view to compare the river levels.

Street View, Jul 2012

Judging by the height and maintenance of the levees behind the tracks, there are times when those tracks are under water. According to the 2004 SPV Map, those are CB&Q tracks that are now used by BNSF and NS.

Street View, Jun 2024

 

The gates were also out of water in 2008, but the river level wasn't nearly as high on the lock walls.

Johns Weeks, 1 of several photos

Johns Weeks

David Webster posted two photos.

Mirandaandseth Wyman: Lock 20 Canton Missouri

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[The river is still running high on Jul 23, 2024]

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NOAA

Those trees on the right are near the westernmost point of Illinois.

Street View, Jun 2012

David Webster posted

Mirandaandseth Wyman: Lock 20 canton missouri

[The grain elevator in the background on the other side of the river is Ursa Farmers Co-Op Co.]

HAER_grid

120mw Parker Dam creates Lake Havasu

(Satellite, 150 photos)

I learned of Lake Havasu when I researched the London Bridge.

usbr
"Parker Dam is a concrete arch structure commonly called the 'deepest dam in the world'.  Seventy-three percent of the dam's structural height of 320 feet [98m] is below the original river bed; only about 85 feet [26m] of the dam's structural height is visible (its superstructure rises another 62 feet [19m] above the roadway across the top of the dam). Parker Dam has a volume of 380,000 cubic yards of concrete. At its crest, the dam is 856 feet [261m] long. Water control is provided by five 50-ft [50m]-square gates." The capacity of the powerplant is 120mw.

usbr
"Lake Havasu backs up behind the dam for 45 miles and covers more than 20,400 acres (32 square miles). The reservoir's total capacity is 646,200 acre-feet. The Metropolitan Water District`s W. P. Whitsett Intake Pumping Plant for the Colorado River Aqueduct is located on the shore of Lake Havasu about two miles upstream from the dam. The aqueduct begins at the intake pumping plant and extends 242 miles to its terminus at Lake Mathews near Riverside, California. About half of the power generated at Parker Dam is reserved by MWD to pump Colorado River water along the Colorado River Aqueduct."

The Hoover Dam posted

Did you know Parker Dam is the deepest dam in the world? About 73 percent of its 320-foot height is hidden underwater. This engineering marvel creates Lake Havasu along the Arizona and California border, transforming the desert into a beautiful oasis.

Inside the Parker Dam Powerplant, four massive penstocks, each 22 feet in diameter, carry more than 41,000 gallons of water per second [5,481cfs] to spin generators and produce clean energy. With a nameplate capacity of 120,000 kilowatts, this powerhouse helps the Bureau of Reclamation remain the second largest producer of hydropower in the United States.

Bureau of Reclamation posted
In July of 1937, the first bucket of concrete was placed in Parker Dam, 245 feet [75m] below the level of #ColoradoRiver. One year later, the last bucket of concrete was placed, and Lake Havasu began to fill in October of 1938. 

nps

Don Barrett Flickr, License: Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC-SA)

LivingNewDeal
This dam is considered a diversion dam. "The diversion of the water from the Colorado River is made by the Parker Dam which raises the water level in the river 72 feet [22m] to the first pumping plant. The main aqueduct consists of 91 miles of tunnel, 55 miles of cut and cover conduit, 65 miles of lined canal, and 27 miles of various kinds of reassure pipe, making a total of 238 miles of aqueduct. The total pump lift, after diversion is completed by the Parker Dam, is 1,614 feet [492m]."

Bureau of Reclamation posted two images with the comment: "Together, the four generator units at the Parker Dam Powerplant put out about 428,000 megawatt-hours of energy annually, providing power to Arizona, California, and Nevada. Each component of the hydroelectric generating unit is impressive. The generator shaft shown here weighs an astounding 22 tons and is nearly 24 feet [7.3m] long! It is built to harness the 40,000 horsepower the turbines produce and spin at roughly 95 RPM."

Richard Polivka: Generator is 76 poles - 60 Hz @ 94.74 RPM.

[Some comments discuss some technicalities about the turbine.]

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1921 Kansas Avenue Bridge over Kansas River and 23rd Street Viaduct in Kansas City

Bridge: (Archived Bridge Hunter; Historic Bridges; Satellite)

Viaduct: (Archived Bridge Hunter; Satellite)

The Kansas Avenue Bridge in Kansas City, KS, connects with the Avenida Cesar E Chavez (23rd Street) Viaduct in Kansas City, MO.

The bridge is 1,395' (425m) long with a main span of 322' (98m). [HistoricBridges]

The viaduct is 2,381' (725m, 1/2 miles) long. [BridgeHunter_viaduct]

HistoricBridges

Because of the flood wall that we see left of center in the above photo, I could not find any decent street views of the bridge. And because of the trees, HistoricBridges shows that it is hard to get a good elevation shot of the bridge even if you get on the other side of the flood wall. But this model of the bridge on a parade float below gives us a clear view of the north elevation of the bridge. In the above photo and the model below, we cans see that the east truss is cantilevered past its pier and holds up the west end of the steel girders for the approach span.

Archived MyPresentPast

The viaduct carries traffic over the floodplain of the Kansas River and... 

Street View, Apr 2019

...connects with the local roads up on the river bluff.

Street View, Apr 2019

The viaduct was built with concrete girders. This is a section  between expansion joints.

Street View, Dec 2023

During construction, a truss span was damaged because high water and floating ice compromised the falsework.

Engineering News
[The bridge in the background is the abandoned Rock Island Bridge.]

The bridge was closed in July 2022 following an inspection. In Mar 2023, the Unified Government finally authorized money for repairs. Repairs were expected to begin in Aug 2023 and be completed by Feb, 2024. [fox4kc]

Those repairs were emergency repairs, and they would be stranded assets because they plan to replace the bridge by Oct 2029. The average daily traffic is 7,100. [fox4kc_presentation]

I have not been able to find when the repairs were actually completed.

There are two interstate and three local bridges across the Kansas River connecting the KS and MO parts of Kansas City. The closure of this bridge in July 2022 removed two out of the three local bridges because the 1919 Central Avenue Bridge had already been closed Feb 1, 2021. [wycokck]

And Google Map shows that the third local bridge, James Street, is "temporarily closed" when I write this in July 2024.

This photo is what motivated my research of this 1921 bridge and viaduct. But I learned that this is a photo of the I-70 Viaduct.

KKFI 90.1 FM posted
Then-and-now: The Lewis and Clark Viaduct opened to the public in 1907 as a roadway bridge connecting Kansas City, Missouri with Kansas City, Kansas. Built to withstand flooding, the bridge featured a pedestrian walkway, lanes for wagon traffic, and streetcar tracks.

LA-1 and MoPac Bridges over the Intracoastal Waterway in West Baton Rouge, LA

LA-1: (Archived Bridge Hunter; Satellite)

MoPac: (Archived Bridge Hunter; Satellite)

In the street view below, they are building the $57.7m phase one bridge. It was supposed to be completed in early 2023. [wbrparish]

Given the big gap still in the bridge in Mar 2024, they did not meet the original schedule.

Construction was halted in Spring 2023 "after DOTD found that the piers for the bridge were sinking more than expected.Since then, a fix was engineered, and the contractor, Kiewit Construction, has had a sub-contractor working on low mobility grouting to stabilize the piers. That is expected to be completed before the end of this year. Kiewit will begin construction work on the bridge again in early 2024." Phase one should be done by the end of 2024. [wafb]

Street View, Mar 2024

Kiewit Corporation posted four photos with the comment:

Progress continues in West Baton Rouge Parish as we work on constructing the new southbound LA-1 Intracoastal Bridge.

The construction of the southbound bridge is Phase 1 of a two-phase project to replace the existing bridges built 60 years ago. The new bridges will provide additional lanes and wider shoulders for more accessibility and safety, help with traffic congestion and be a more efficient route for hurricane evacuations in Louisiana. 

Kiewit is the general contractor on Phase 1. Phase 2 includes the demolition of the old bridges and the construction of the new northbound bridge.

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[Note the I-10 bridge over the Mississippi River in the right background.]

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The new bridge uses steel girders in the middle and concrete girders on the ends.

Street View, Mar 2024

There is a good view of the concrete girders on the north end.

Street View, Mar 2024

The Port Allen Lock is on the other side of this bridge.

Street View, Mar 2024

Madison Ave. and 145th St. Dam Bridges over Harlem River in New York, NY

1907 Madison Avenue: (Archived Bridge Hunter; NYC; Satellite)

1900+2007 145th Street: (Archived Bridge Hunter; NYC; Satellite)

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Madison Avenue Bridge

 

River View, Oct 2016

nyc
The 1,892' (577m) long bridge has a main span of 300' (91m).

Street View, Jun 2011

United States beauty posted two photos with the comment:

The Madison Avenue Bridge is a significant bridge in New York City that spans the Harlem River, connecting the neighborhoods of Manhattan and the Bronx. Opened in 1900, the bridge was originally built to accommodate both vehicular and pedestrian traffic. It features a steel arch design, which was innovative for its time, and is noted for its distinctive architectural style.

The bridge has undergone several renovations and restorations over the years to improve its structural integrity and maintain its functionality. Today, the Madison Avenue Bridge primarily serves vehicle traffic, and it features a walkway for pedestrians and cyclists, allowing for safe passage across the river.

The Madison Avenue Bridge is an important transportation link, facilitating travel between the two boroughs and providing access to various local amenities and neighborhoods. Its location also offers scenic views of the Harlem River and the surrounding area, making it a notable landmark within the city’s extensive network of bridges.

Cassandra Jenkins Pannell: Also know on the Manhattan side as the 135th street bridge and on the Bronx side as the 139th St Bridge.

Vincent Perrelli: Probably one of the few toll-free points of access between The Bronx and Manhattan, an I right?

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Jeffrey Gluck posted
Madison Avenue Bridge

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145th Street Bridge

River View, Oct 2016

nyc

The span was replaced in 2007.

nyc
Floating into place

 

nyc
Passing 3rd Ave. Bridge

Jeffrey Gluck posted
145th Street (Lenox Ave.) Bridge

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Macombs Dam Bridge

 

This content has been moved to "1895 Macombs Dam Bridge over Harlem River in New York, NY."