My only experience is a planned trip that never happened.  We were going to use   (You need to Login or Register and they seem to be the local expert on access and routes (besides Phil Cotton).  They facilitate the train ride to Collins or Allanwater or you can drive to misc. lakes and rivers to access.  Of course there's fly-in options galore.  The   (You need to Login or Register is pretty comprehensive.

We were going to take the train to Allanwater.

  (You need to Login or Register (Inuk. member around here) was there a few years ago I think.  I believe he was on a park clean-up type trip.  He'd be a better source for info.  Drop him a personal message.