I hiked Mount Hoffman in Yosemite today and at the top there was this metal plate bolted to the rock with 4 metal rods welded to it. On the side you can also see some rivets so possibly there was something attached to it.

What could it be?

Metal plate

  • 1
    Not for sure, but it is likely a survey mark of some sort if it is placed horizontally on a rock surface. These are often on the highest peak around, but not always, sometimes it's just one with easy access or a good vantage point to site many other peaks/features. Sometimes survey marks are "destroyed" and no longer used as reference points as might be the case here.
    – bob1
    Sep 8, 2019 at 3:35
  • It's nothing like any survey monument i've ever seen.
    – Martin F
    Sep 9, 2019 at 17:17

1 Answer 1


That is half of an old summit registry box. That one is missing the top and might not be the exact style but the full ones look like this.


You can see more pictures of them here and a history of the summit registers in the Sierra's here.

Its obvious that its aluminum because it hasn't corroded and the point of the "rollers" is to keep the record book above moisture because the containers aren't waterproof. Unfortionaly, people steal and vandalize these boxes.

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