H&BTM Bridges over Raystown Branch Juniata River and US-30 near Everett, PA

1937 Trail/Fishbelly: (Archived Bridge Hunter; no Bridge Hunter; no Historic Bridges; Satellite)

Thropp Viaduct: (no Archived Bridge Hunter; Bridge Hunter; no Historic Bridges; Satellite, approx.)

H&BTM = Huntingdon & Broad Top Mountain

Lincoln Highway Overview

1937 Trail/Fishbelly

Street View, Nov 2024

It has been added to the trail.

Eldon Martin, Feb 2021

Thropp Viaduct

This bridge also went over US-30 (Lincoln Highway). 

c1921 Postcard via BridgeHunter

5 of 8 images posted by PRR Bedford Branch History Preservationist with the comment:

Between Everett and Mount Dallas, there was a spur that rounded a 180-degree turn as it crossed the Raystown branch of the Juniata river to the south side. There it served the Earlston Furnace. 

This was called the Thropp bridge. 

built in 1884 by the Everett Iron Company.

The furnace went idle shortly after opening, but was put back into operation when the company was purchased by Joseph Thropp in 1889 and put into blast in 1890. The furnace was shut down in 1923, and the company went bankrupt in 1933. In June 1933, the plant was sold to the Bethlehem Steel Corporation, who began dismantling it in June of 1934.

This furnace was connected to the H&BTM using the Thropp Bridge. But it was also directly connected to the PRR too. Refer to the map and you can see the direct connection bypassing the Thropp Bridge.

Byron Smail: Earlston furnace was 1 of the 4 major latest and most modern iron furnaces in the Juniata Iron District.

Rockhill, Saxton, Riddlesburg, Earlston

a

b

c

d

e
[With the Thropp bridge in the background.]

These maps are wrong because they show the bridge heading West to the Pennsy tracks rather than curving back East to head to the Earlston Furnace. And BridgeHunter is wrong because it claims that the bridge carried Penn Central. The bridge carried H&BTM so that both Pennsy and H&BTM terminated at the iron works.

PRR Bedford Branch History Preservationist commented on their own post

Peter Fleszar commented on the above comment
here’s a map of present day showing the hiking trails on both sides of the gap relative to the old rail lines

rail.guide

Alverno Dam on Black River near Cheboygan, MI

(Satellite)

See April 2026 Flood for more photos of this dam.

Anchor In Marina and Storage posted

A great shot from Craig Passeno

The Alverno Dam keeps the upper Black River and Black Lake stable, it feeds to the ‘Black River ‘ which flows in to the Cheboygan River , right at Anchor In. All the white are the sand bags that were placed today. 

Give her strength!

Thumbwind posted

**Black River Dam, Cheboygan County, Michigan**

Black River Dam in Cheboygan County fills this postcard with timber cribbing, a riverside powerhouse and water pouring over a spillway. Several people stand on the dam’s platforms and along the rocky banks.

The University of Michigan’s matching archive record links the view to Alverno Dam, south of Cheboygan. The hydroelectric site dates to the early 1900s and used the river’s flow to generate electricity. Water leaving Black Lake passes through the Lower Black River toward the Cheboygan River and Lake Huron.

https://michigan4you.com/history-of-mullett-lake-michigan/black-river-dam/

Facebook Reel

1957 I-880 Cypress Street Viaduct collapsed Oct 17, 1989, at 5:04pm during the magnitude 6.9 Loma Prieta earthquake

(Satellite)

cnu, Source: H. G. Wilshire for U.S. Geological Survey
engineering
"In October 17, 1989 the Loma Prieta earthquake hit the San Francisco Bay area, causing over $12 billion in damages and claiming 64 lives. Over half the victims were on the Cypress Street Viaduct during the quake....On October 17, 1989 at 5:04 p.m., a devastating earthquake, measuring 7.1 on the Richter Scale, rocked the city of Oakland, causing billions of dollars worth of damage and a death toll of 64....The deaths on the Cypress Viaduct, 35 in total, accounted for more than fifty percent of the 64 lives taken during the earthquake. Fortunately, only about eighty vehicles were on the affected stretch of highway during the earthquake — a fact attributed to a sporting event: the San Francisco Giants were playing in the World Series and people were indoors anticipating the commencement of the game."

American Experience | PBS posted

Thirty-seven years ago today [Oct 17, 1989], just before Game 3 of the 1989 World Series, fans at San Francisco's Candlestick Park felt the earth shake beneath their seats.

It turned out to be the 6.9 magnitude Loma Prieta earthquake, which resonated throughout the Bay Area, ultimately responsible for 63 deaths and thousands of injuries.

📸: Collapsed sections of the Cypress Street viaduct of Interstate Highway 880 in Oakland, California, in the aftermath of the 1989 Loma Prieta Earthquake. (H.G. Wilshire/United States Geological Survey)

[The comments are interesting. Several people describe what they saw during the earthquake.]

localwiki
engineering
"During the Loma Prieta earthquake, the entire Viaduct structure began to vibrate tremendously (Peterson, 1990). Whereas well-graded soils helped to dampen vibrations (Yashinsky, 1998), the soft “bay mud” upon which most of the structure was constructed actually served to increase the amplitude of vibrations by up to five times in comparison to that of the rest of the freeway which was built on rock. In addition, it was later determined that the angular frequency of the seismic waves almost exactly matched a natural angular frequency of the individual horizontal sections of the structure (Halliday et al., 1993). It is suggested that these sediment resonances could have played a significant role in contributing to the freeway collapse, since the resulting forces were not anticipated in the original design.
"The Cypress Street Viaduct was designed as a two-tier multi-lane highway constructed of reinforced concrete (Moehle, 1997). Upper and lower levels were connected by two-column bents in a combination of cast concrete and four pin (shear key) connections. The upper deck in some sections was not securely fastened to the lower deck, making this concrete susceptible to vibrations. As the bridge vibrated during the earthquake, the pins connecting the upper level to the lower level also began to vibrate, causing the concrete surrounding the pins to crumble and break away. Without the presence of concrete under the support columns, the columns slid sideways under the weight of the upper deck and allowed a large portion of the upper deck to collapse (Yashinsky, 1998)." The concrete itself tested as structurally sound.

infinityeng

Part of the land used for the spiral ramp is now the Cypress Freeway Memorial Park.

cnu,  Source: California Highways and Public Works
"The construction of the Cypress Street Viaduct displaced over 600 families and the surrounding urban renewal projects destroyed over 5000 residences."
This source puts the strength of the earthquake at 7.1. The viaduct collapsed between 7th and 18th Streets.  (I question this range. See the dotted red line on the USGS diagram below.) The highway was carrying 160,000 daily vehicles. The $1.1b replacement was built primarily over railroad land rather than through residential and commercial land. The old route was rebuilt as the $13m Mandela Parkway.

localwikie

I read about this collapse many years ago. I remember that some drivers deliberately parked over the columns thinking that would be the strongest part of the viaduct. Unfortunately, that is where there was a thick bent cap overhead for the upper deck. When the upper deck collapsed, those drivers were crushed. Drivers that were away from the piers survived because there was a gap between the two decks after the collapse.

infinityeng
The earthquake lasted for 15 seconds.

usgs
"The part of the Cypress freeway structure in Oakland, California, that stood on soft mud (dashed red line) collapsed in the 1989 Loma Prieta earthquake, killing 42 people. Adjacent parts of the structure (solid red) that were built on firmer ground remained standing. Seismograms (upper right) show that the shaking was especially severe in the soft mud. (Photograph by Lloyd S. Cluff)"
[A source that I have lost indicated that the soft mud vibrated with a frequency that matched the resonant frequency of the viaduct. Evidently, the vibration of the sand & gravel had a different frequency so that part survived.  Even if they had reinforced the viaduct, it may not have sruvived because the issue of matching frequencies between the ground and structure was not a known design issue until this failure.]

This map shows how the freeway cut through a residential neighborhood.

1980/81 Oakland West Quad @ 24,000

A satellite image shows how the replacement highway went around the neighborhood.

Satellite

1922 Green and 1978 First Major USA Cable-Stayed Bridges over Columbia River at Pasco, WA

1922: (Satellite)

1978: (Archived Bridge Hunter is broke; Bridge Hunter; John A. Weeks III; Satellite)

nps

The Green Bridge replaced a ferry system to span the Columbia River.

HANFORD HISTORY PROJECT

Allyson Thiss posted
Tri cities History!!

Stan Johnstone commented on Allyson's post
[There are some comments that driving over this bridge was part of people's drivers education.]

I can't imagine a more functional (i.e. plain) cable stayed bridge. 

This is a fan design as opposed to the harp design. Most of the bridges we see today are a hybird of the two designs. Specifically, the tower anchorages are spread out along the top part of the towers. [midas]

Street View, May 2012

The 240' (73m) tall towers hold up a main span of 752' (229m). The total length of the bridge is 2,503' (763m). "This bridge is the first major cable stayed bridge to be built in the US. It is so unique that it has become the unofficial symbol of the tri-city area." [JohnWeeks]

This source states that the length of the main span is 981' (299m). The width of the bridges went from 19' (5.8m) to 60' (18.3m). 

tri-cityherald
"The 1922-built green bridge is overshadowed by its replacement, the Ed Hendler cable bridge, which opened in 1978. The old bridge was demolished in 1990 after a fierce battle to preserve it failed. National Parks Service"
"The 2,500-foot span carries more than 16,000 vehicles per day. It’s “underused” according to the Department of Transportation."

US-6 (I-195) Bridges over Providence River in Providence, RI

Old: (Satellite, the piers were repurposed for a pedestrian bridge.)

New: (Satellite)

US-6 Overview

Normally, I would not use a 2008 Street View because of their quality, but this is the only view available since the bridge was soon torn down. I included the arch of the replacement I-195 bridge on the right side. I'm guessing that this old bridge was a steel-girder bridge.

Street View, Oct 2008

They left the piers.

Street View, Sep 2012

The Michael S. Van Lessten Memorial Pedestrain Bridge was built on the old piers.

Justin Case, Aug 2019

I-195+new US-6

Street View, Aug 2025

Street View, Aug 2024

Greenmark Geography posted

Providence took down a freeway bridge and kept its piers for something better.

Until 2009, I-195 crossed the Providence River right at the south edge of downtown, on a stretch of highway that was about 45 years old. The 2008 view on top shows the bridge full of traffic.

Rhode Island's $610 million Iway project moved the interstate south, onto a new eight-lane bridge. The last piece of the new highway opened in late 2009, and the old one came down over the next few years, freeing about 20 acres of downtown land.

The highway bridge went too, but its piers stayed in the river. In August 2019, a $21.9 million pedestrian bridge opened on top of them, with new parks at both ends. Since 2020 it has carried the name of civil rights advocate Michael S. Van Leesten.

Have you walked across it yet?

This is how US-6 used the old bridge. I'll bet US-6 used to use Angell and Waterman Streets to get through town.

1996/2000 Providence Quad @ 24,000

This map blend shows how US-6 was moved further downstream on the river.

This is a blend of the 1996 map with a current map.

1874+1932 Trail/Katy and US-40 Bridges over Missouri River at Boonville, MO

Katy: (Bridge Hunter; no Historic Bridges; Satellite)

US-40: (Satellite)

US-40 Overview

This view is looking south from the US-40 Bridge.

Street View, Jul 2025

Dmitry Choukline, Sep 2026

Dmitry Choukline, Sep 2026

Dmitry Choukline, Sep 2026

The depot a few blocks south of this bridge is a trailhead for the Katy Trail.

"The first Katy bridge in 1874 was the fifth bridge across the Missouri. The current bridge, a 1932 replacement, was the longest lift-span in the united states when constructed." [plaque]

The lift span is 408' (124m). [BridgeHunter]

SaveTheKatyBridge

This must have been before dams were built on the Missouri River.

SaveTheKatyBridge

The US-40 bridge is a combination of concrete and steel girders. My guess is that they are unloading potash for fertilizer.

Street View, Jul 2025

Market Street Stub for Chicago's Lake Street "L"

Terminus Depot: (Satellite, the stub was removed when Waker Drive was built.)

David M Laz posted
DID YOU KNOW THAT? Once upon a time, there was an "L" stub that ran from the Lake Street "L" and ended in front of the Opera House on Market Street (now Wacker Drive).
Alan Follett: Yes; the original downtown terminal of the Lake Street ‘L’, before it was connected to the Loop. It was abandoned in 1948.
Leonard Carey Williams: Samuel Insull's station he owned the Opera House he owned the trains he would park his private car at the end of the line it was good while it lasted
Paul Webb shared

Nicholas J Vetrovec commented on David's post
It was the fist section of the L built in the Loop and was part of the Lake Street Elevated rail known as the Market Street stub 1893. It was supposed to be removed in 1897 when they opened the fist section of the Loop but wasn't removed until 1948 leaving way to extend the double decked Wacker Drive. https://www.chicago-l.org/stations/market_term.html 

We can see the junction of the stub with the line that now connects with the Loop. Also, on the right side of the photo, we can see the stub going south of Randolph Street.

Frank Piha posted
Chicago 1925. No Merchandise Mart yet. There is a train station where the Mart will be built. The Chicago Temple Building on the SE corner of Clark and Washington was the tallest building in Chicago from 1924 to 1930. The Franklin/Orleans bridge is raised. The Clark bridge pivots.
[The construction of Wacker Drive is in progress at Wolf Point, but they have yet to clear the buildings along South Water Street. However, this photo must be after Aug 31, 1925 because that is when the replacement produce terminal opened. So South Water Street is now vacant, and the buildings can be cleared for Wacker Drive.]

Comments on Frank's post

This map shows that the terminus depot was just north of Madison Street.

Terry Gregory commented on Frank's post