ken burns "the national parks: america's best idea" documentary

This documentary is broken into 6 episodes by the producer of the film, i will try to get the six episodes.
This is still an on going search but will be updated, if anyone could post any episodes that are missing, that would be more than helpful.

• A PBS 30 min preview of the film:
  https://www.youtube.com/watch?v=mx8WbZIWCSM
  
  Episode 1, "The Scripture of Nature":
  https://www.youtube.com/watch?v=nr4YG8ra2mA

The next episodes will be uploaded as soon as they can be found. But for now here is a link where you can read a short page of each episode and if you want, it is a good way to get some info.
LINK:

• http://www.pbs.org/nationalparks/history/ep1/