The NPS welcomes comments on the Plan. The comment period closes on June 16, 2008 at 11:59 PM, Mountain Time. All comments must be submitted or (in the case of letters sent by regular mail) postmarked by that time.
then at the bottom of the page:
This Action Alert Campaign is Closed.

The NPS docs are
here. The Plan is split up into 12 PDF files totalling 30.8MB.