Even though the 13th fairway is today split by the bunker complex, there are some Bethpage historians who maintain that the original desigtn did not call for it, nor was it built that way.
According to them the left side of the fairway swung very close to the 11th tee, and actually sweeping over toward the now overgrown area between 13 & 14.
They are unsure as to the date when the right-side fairway on 13 was added, but most certainly no later than 1956 when the Yellow course was built. The reason behind the change was one of safety for those on 11 tee.