...doing trip recon for our March trip; here is the response to the inquiry I made regarding hanging camping hammocks (with tree-protective straps, of course)...
Greetings from beautiful Monument Valley.
Yes ,we do have tenting areas with trees.However the company does not allow hammocks or anything heavier than a cloths line on our trees.
Gouldings Camp Park
As a related aside, it might be useful, if not already in existence, to begin compiling a camp-friendly/unfriendly site list by state..