On Sept. 27 PBS will begin airing Ken Burns' 6-part, 12-hour documentary: "The National Parks: America's Best Idea."
Local environmental reporters may find demand for stories about their local National Park System unit (they are not all parks). Freelancers may also find it is not too late for a pitch. There are scads of good stories in parks. Wherever you are, there may be an NPS unit  closer than you think.
The official site is online here,  and signs are that this will be a full-scale PR rollout.
There are many pre-screenings and press events.