What can be done about trespassing, dumping, etc.?

Trespassing
Contact the game warden for that county.

Boundary Encroachment or Disputes, Drug-Related Activity, and Dumping
Notify the Rayonier contact listed in Paragraph 2 of the HUNTING LICENSE AGREEMENT and describe the problem and location.

See also: What is the land posting policy? | Are locks allowed? | What is the camping policy? | Are guests allowed on the property?