For me "upland" hunting is for pheasant, quail, grouse, partridge, or dove. Generally it is "walk up" hunting done with dogs. I have always assumed the "upland" came from the English hunting tradition but apparently not. In the US I don't think it has anything to do with elevation as the traditional Southeast bob white hunt was usually done just a few hundred feet above sea level. I live at 3700 feet. Duck, goose, and crane are not considered by me as upland hunting.
Upland guns are lighter than water fowl guns because they are intended to be carried all day while walking behind the dogs. You practically never see anyone carrying a slinged gun behind pointing dogs here. Since they are used behind pointing dogs at closer range there are lots of 16, 20, 28, and 410s used in upland hunting.
I cannot answer why I consider doves upland game as they are mainly taken by pass shooting or ambushed coming into a pond in the evening or a grain field during the day.
Best,
Mike
