This area does not count as wilderness, despite there being countless mushroom patches, and both adjacent areas do count a such.

Also, there seems to be no exploration XP but it's not exactly easy to reach. Same for the area beyond it: Sand Canyon - The Wastes (But at least this one is marked as wilderness).

I can confirm this about the Beyond the Canyon part - no XP given.

Never been to The Wastes, so i can't confirm or deny that.