Map Monday Bonus: Saint Paul’s Sand Rock Tunnel Sewers

Via Dana DeMaster and Than Tibbets’ Twitter conversation, here is a map of a mysterious and unknown subterranean engineering feature in Saint Paul, Minnesota’s weirdest city in some ways. Here is your map. The “sand rock tunnels” are in yellow.


[.pdf is here.]

The initial query came from yet another West 7th Street rumor:

It turns out to be true. The explanation is thus:

Here’s an illustration from Teresa Boardman’s blog. That and many more oddities can be found in the links on Twitter.

They say that “s**t flows downhill”, and in Saint Paul that is literally the case. is a non-profit and is volunteer run. We rely on your support to keep the servers running. If you value what you read, please consider becoming a member.

, , ,

3 Responses to Map Monday Bonus: Saint Paul’s Sand Rock Tunnel Sewers

  1. Dana DeMaster
    Dana DeMaster May 7, 2018 at 4:15 pm #

    I’m still shaking my head over this one. Really? My sewer is a cave?? I mean, make do and all, why build pipe when there are caverns? I just wasn’t expecting this one to be real.

    Now, snakes. How does this all relate to snakes? Lots of snakes.

  2. NathanT May 8, 2018 at 5:38 pm #

    Check out Greg Brick’s “Subterranean Twin Cities” for more on this.

    • Jim Stockton May 16, 2018 at 11:54 pm #

      Greg Bricks books are full of incorrect info, unfortunately. Many sites have proven his data to be wrong and fabricated 🙁

Note on Comments welcomes opinions from many perspectives. Please refrain from attacking or disparaging others in your comments. sees debate as a learning opportunity. Please share your perspective in a respectful manner. View our full comment policy to learn more.

Thanks for commenting on!