Donald Ross taught many people the business and those people have spawned descendents as well:
Of course, most people are aware of J. B McGovern, Walter Hatch, and Walter Johnson, as well as Ellis Maples being first generation Ross disciples. There were also Orrin Smith, Skip Wogan and James Harrison.
Orrin Smith worked a bit with James Harrison after Ross's death. James Harrison taught an Architect named Fred Garbin who is (was?) out of the Pittsburgh area. Harrison was his father -in-law. I believe Garbin taught Ed Beidel, who I think I've seen float around GCA a time or two. I believe he also taught a female Architect whose name escapes me at the time (Lorrie Viola?).
Orrin Smith taught two Architects named William Mitchell and Al Zikorus, whose son now practices golf course design today.
Skip Wogan spawned his son Philip in the business.
Ellis Maples probably has the longest family tree, descended from Donald Ross (who was descended from Old Tom Morris and Allan Robertson). Ellis taught Ed Seay in the early 70's. Ed Seay then went on to be Arnold Palmer's partner from day one. Ed Seay taught Robert Walker out of Florida for starters. I guess technically every Palmer guy could fall under this tree branch.
Ellis also taught his son, Dan Maples. Dan, in turn apprenticed Mike Gleason, who is now on his own, and myself, Richard Mandell.
Of course I wll take this time to point out that I am a pretty straight-branched descendent of Donald Ross, Old Tom, and Allan Robertson. Although most people would say a Dan Maples course is nothing like Ross would do, I will point out that his methodology is just what Ross practiced and was passed along to me, although my course work does not reflect something Dan Maples would do.
The methodology and the understanding (from the ground up) of Donald Ross is what is most valuable to my practice and something most Ross restoration Architects do not possess. It also gives me great insight into Donald Ross restoration efforts that someone should really capitalize on! I look forward to you all spreading that gospel!
Great segueway, huh? I ought to be a DJ. I hope someone else can fill out any more bottom branches of the Ross tree.