Brandon-Mt. Auburn Bridge

That would’ve been the demolished McFarlane Bridge

https://bridgehunter.com/ia/black-hawk/mcfarlane/

There was apparently a rail bridge there. in southwest Buchanan county.

waterloo, CF and Northern RR

just north of J.D. Winegar's land in 1923.

Aerials from historicaerials show the historic bridge downstream on the original alignment of 22nd Ave (Now 22nd Ave Ln.), but show no signs of remains on the modern alignment

What is possibly happening here is that what is being seen are remains from pilings made during construction. Construction pilings are often mis-identified as remains of previous spans.

I myself am not in the area as well, and I have a short list of spans closer to me that need photographing well before I'd stray that far north.

This area needs some research. there appears to be two locations where a bridge may have crossed.

I'm unable to research further at this time, but historic atlas or historic aerials may provide some more clues.

I'll try to remember to come back to it. I'm about 80 miles north of the area, so maybe I'll make a trip in the future too.

Any one out there knows if there was another bridge just north of the bridge that fell in 1929 there’s old wooden bridge pylings that you can see going at a angle from the east bank

Any one out there knows if there was another bridge just north of the bridge that fell in 1929 there’s old wooden bridge pylings that you can see going at a angle from the east bank