Surfacing issuing in maple?

Has me wondering if it could be from water, it can go deeper than what sanding a scraping remove. Have you tried a pass with a hand plane of a pass through a planer?

mother nature isn't consistant in its color pallet, hence the reason wood workers love her products.

i'd say its the tree that spawned the piece, but sure others will have a different take on it
can't go wrong with any wood, jmo
rj in az

Looks like a deep wear stain to me. I have seen it before on some of my boards. as RJ said, jmo.

Hard to tell:
- Sticker staining?
- Panel glue up stain or defect?

Use a straight edge and check if surface is flat on top of that area. Could be a depression, and need to keep going with thickness reduction. If it's sticker staining, edge might show depth of stain.
It is too uniform across many years of growth to be naturally created. I blame a human for that color band.

Cheers!

No glue up / stain issue. Wood was run thru a planer from 4/4 to 3/4 and the stain was still there. So it's probably a (deep) sticker or water stain. Sigh. Wood is natural.

Looks wet. Do you have an accurate moisture meter? I think with one you would see variances in %.

You could always use my favorite technique when dealing with wood. Embrace the imperfections. OR, just use the parts ya like, you have to be happy with the end result, this is why they always suggest at least buying a 10% overage on material, so you can weed out what doesn't make ya smile.

Best of luck.