If you don't live in the south, you might take care there to enunciate when discussing this topic. As in " You got any I.D.? ", and the response too often will be " 'bout what? "

Okay, that off my chest ... I'm with jj2044 here. It seems to me that the drivers license I carry is sufficient. Certainly some sort of identification in the backpack is a good idea too.
Dog tags made practical sense in the service; I'm not inclined to wear something like that now. Exception might be going for a run in clothes without pockets, but that doesn't apply to hiking scenarios.