There is no doubt that particular bunkering scheme was a common one used by Ross on his par-3s, but I'd be interested to know how many of those modern holes had the scheme originally and how many were added later by other architects, especially architects specializing in Ross restorations. Based on the prototypical look of most of those bunkers my guess is the majority of these courses have been 'restored' in the last decade.
Where is Salisbury?
Tom,
The Country Club of Salisbury is in Salisbury, North Carolina, which is about 40 miles northeast of Charlotte. http://www.ccofsalisbury.com/viewCustomPage.aspx?id=1
Carolina Golf Club in Charlotte presents a good case in point about the "restoration" of cross bunkers. Mark's original post above shows par 3 number 3 (232 yds.) at Carolina. The cross bunker was restored in Kris Spence's 2008 restoration/renvovation. Immediately prior to Kris's work there were no bunkers on this hole. However, Ross's original 1929 drawing of the course shows a cross bunker in this location. The same is true on no. 9 at Carolina, also a long par 3 (237 yds.). Immediately prior to the renovation there was no cross bunker on this hole, but the Ross drawing showed a cross bunker and Kris put one in at that location durning his work. Possibly Ed Oden could post a photo of that hole as well. The best I can do is refer you to Ed's photo tour of the entire course. http://www.flickr.com/photos/eko_gfl/sets/72157608575550343/show/
For comparison of the Ross drawing and Spence's restoration plan, see Ed's initial post in his tread on Compliation of Routing Maps, Plans and Architectural Drawings (http://www.golfclubatlas.com/forum/index.php/topic,43053.0.html), keeping in mind that no. 3 today was number 8 on the Ross plan, while no. 9 today was no. 5 on the Ross plan. So, in the Carolina GC situation the cross bunkers were not there on 3 and 9 prior to the Spence restoration/renovation, but were added by Spence to reflect what was shown on the original Ross plan. My understanding, second (plus) hand, is that many of the original Ross bunkers on the course were eliminated durning WWII as a maintenance cost-saving measure.
Tom:
Adding to Carl's post, at Carolina the cross bunkers on the 3rd and 9th holes had been lost over the years, probably more from an expense standpoint than anything else. But they were in Ross' original drawings and Kris Spence restored them as part of his work several years ago. Here are pictures of the restored 9th at Carolina:
From the tee it appears virtually like a greenside hazard...
But from this angle you can see that it is really quite a bit short of the green...
And from behind the green, you can again see that the bunker is well short...
As for some of the other holes noted in this thread, I know that the short cross bunkers on the 3rd hole at Charlotte and the 9th hole at Biltmore Forest were similarly on Ross' original plans, lost over time and reinstated as part of recent restorations. The short right bunker at Mountain Ridge #14 is on Ross' 1929 plan which Pat Mucci provided for the map thread. I don't know the story with Mimosa Hills #9 and #13 or Sedgefield #3. But it is my understanding that Kris Spence had Ross' drawings for both of those courses and use them as the basis for his work. So I am pretty sure these examples were Ross originals as well. As for #17 at Salisbury, I have no idea whether it is original or not. But they do have Ross' drawings in their clubhouse. I'll try to take a look at them the next time I am there. In any event, I think it is pretty clear that the majority of these par 3 cross bunkers were originally conceived by Ross rather than an intermediary architect, even though their current iteration may be a product of a restorationist's work.