I read all the Links provided.
Nowhere did I see geocaching as absolutely prohibited. I did see this quote in all the links:
"Without a permit, prohibiting landing or launching aircraft, discharging paintball guns,
placing of geocaches,"
So if a permit was approved a geocache could be placed. Seems to be similar to the National Parks stance.
I also noted this quote:
"Jeff Gould, Chief, Bureau of Wildlife, presented the revised rules for public use of department
managed lands. Mr. Gould stated that these rules help keep public use of Department lands
consistent with wildlife habitat needs, public safety, and other management constraints. The last
major update of these rules was in 1993. The proposed changes are:
• Allowing the Director to delegate more authority to regional staff".
Seems quite appropriate that regional staff may permit geocaches in some areas.
If you look up at my link above, there is a rule there which does expressly state that placing a geocache on WMA lands is prohibited.
Public use restrictions
You have to scroll down a bit, look under rule 100.22 It is posted under public use restrictions for activities prohibited