What I am confused about is whether or not an Overnight Permit is required if I spend one or two nights at the Whitney Portal Campground at the TrailHead.
one only needs a permit - day use or overnight - if one enters the whitney zone.
whitney portal and the camping areas in that area are not in the whitney zone.
on the main trail you will encounter the whitney zone boundary sign - can't miss it unless you're sleeping - between lone pine lake and bighorn park. about three ( 3 ) miles up the trail from the portal.
tom harrison maps has a 'mt. whitney zone trail map'. widely available + on the net.
