One of the central events of the Twin Peaks pilot was when a partially clothed and obviously battered Ronette Pulaski stumbled across this railway bridge the day after Laura Palmer's murder, then immediately fell into a coma. Their cases must be related, but how? Their fellow students all agreed the two girls barely knew each other. Ah, yet another piece of the mystery unfolds!
We stumbled onto this bridge by accident, although we had planned to seek it out eventually. But it is literally down the road from the Twin Peaks welcome sign - as we were driving, it suddenly appeared out of the wilderness in front of us.
As a New Yorker, I like to think of this as "The Ronette Pulaski Bridge" - that sounds fitting and familiar to me. Its real name is the "Reinig Bridge", and it was originally a trunk line meant to shuttle lumber from the Snoqualmie Falls Lumber Company mill (aka the Packard Sawmill).
(If you want to have a little fun with that map, follow the line of new trees where the rail line used to be to the north and see if you run across anything you recognize. You should find two more show locations pretty easily.)
Here's the bridge today:
Amazingly, it is in basically the same condition as in the show pilot 26 years ago. The same amount of rust :)
That said, it is now a pedestrian bridge, part of the Snoqualmie Valley Trail:
In person, it's obvious to me why Lynch and/or Frost wanted to use this bridge in the show. It sticks out oddly as a dilapidated, imposing, industrial structure in the middle of beautiful forest greenery.
Incidentally, while I'm sure it's possible to get the same angle and background compression as the shot from the show at the top, it's difficult. They were using a really long lens to make those mountains appear that close, and standing somewhere that I don't think you're really meant to stand. I don't have a long lens for my current camera, and I couldn't see an obvious spot to get that angle anyway. They were on the other side of the bridge, and must have been standing at the very edge of the riverbank. (There is a small beach on the side of the bridge I was on, but nothing at all on the other side - it's just trees right to the edge of the bank.)
I did get a shot of how the mountains look in real life, from the bridge: