Kirk:
The subject of copyright in golf course design is often addressed in the contract between owner and designer. In my most recent contracts I retain the copyright to all plans for the course, and the client is granted a license to use the plans.
I don't know that there are any design ideas that are clearly original enough to deserve copyright protection. I do know that those "Tour 18" courses were told by court order to quit using certain trademarked names of other courses as part of their advertising and promotion, but there was never a suggestion that the holes themselves were protected from duplication.
A couple of designers (Nicklaus included) have clauses in their contracts that if the course is "materially changed," they have the right to withdraw the licensing use of their name as the architect. I don't know if Jack has ever exercised the clause or not ... generally, if a client was unhappy with the finished product, an architect would want to do something so they'd be happy, unless the relationship with the client is beyond repair. And ultimately, all designers understand that if they sell their work to someone else, it's at their disposal forever more.
My suggestion of nominating three courses to be preserved (first suggested some months back) was an attempt to find a middle ground. If a modern designer were to nominate three courses as worth preserving, that would grant them some special status among the many which bear his name. I would guess there are some owners who would think that special status was worth the same sort of hassles associated with owning a "landmark" building -- in fact, I suggested limiting it to three per architect so that it wouldn't become just another level of "signature" design that everyone would want to claim.
If the owner doesn't want to register his course, then it's a moot point, and let me reiterate, I'm okay with that ... it IS his course. And, for that matter, if a future owner wanted to violate that landmark status, I don't know that anyone could stop him from doing so. Oakmont is supposedly on the National Historic Register, and that hasn't kept them from planting trees, tearing out trees, building ridiculous back tees, or getting their greens too fast.
The only purposes of my suggested program would be to hold up some courses as the best remaining examples of a designer's work, and to try and put a few speed bumps in the path of course owners who are constantly finding silly little things to change for the sake of change itself, which (despite everything I've heard from Paul and Jeff and Mike) is still, in my experience, one of the main reasons stuff happens on older golf courses.
And I know I can get Mike Young on my side with this simple hook ... just imagine, what if the Donald Ross Society only had three courses to preserve, and would stop meddling with the rest?