It is clear from the rules that, with regard to the same "type" of ride, the intent is to complete the same general type of ride. An in-state Saddlesore 1000 is a special form of a standard SS1K. So you can mix and match any special form of Saddlesore 1000, for example, to qualify for the 4 Seasons award.
Ira Agins
Iron Butt Association