Hi Wello,
I have only been up to KWI as a day trip, also taking in Milligans Peak & Mt. Pitt.
This is a really fantastic day trip & from memory only took about 4-5 hours return.
There is a very good track to KWI; to get to this:
-about 10ks (or so) west along the Lyell Hwy from Derwent Bridge,
-turn left onto a gravel road just after crossing the bridge over Navarre River & follow for about a k
-park next to the boom gate on the right signifying the start of the 4WD track
-follow this for maybe 3-4k; the 4WD track will stop & a walking track with register box will take you to the summit of KWI (complete with array of weather station equipment).
-the off track walking to Milligans Peak & Mt. Pitt is delightfully easy on alpine grasses / heaths.
Haven't been any further along the range than here yet so can't really comment, tho it is supposed to be pretty easy gouing apart from King William gap;
a classic old tale of a traverse of both the KW's & POW's ranges (The Royal Traverse) here:
http://www.subw.org.au/archives/POR/Thrash.htmlI have also been in to Mt. Hobhouse which initially follows the track which takes you to KWII etc.
To get to this:
-take a left along the Butlers Gorge Road just before Tarraleah & follow right to the end to the Clark Dam, park here.
-sneak through the baricade (you can squeeze through without your pack on, which can be lowered from above), walk along the dam & clamber around the fence at the other end (I shouldn't promote ninja missions, but everyone else seems to do it
).
-follow the very good track which goes around the shore of Lake King William (or what is left of it).
-you will eventually come to an unexpected register box for the KW areas, which from what we gleaned gets very little use (I think we were the second entry in over 6 months).
-keep following the tracks to Lake Rufus (I think?) - maybe others who have been there could comment.
Hope this helps, if only a little.
Cheers.
Stu B.