Anson,
take a look at www.nps.gov/alaska
You'll find a list of national park areas. The Denali site is extensive and has info on the bus system, shuttles, hiking, etc. Kenai Fjords (headquartered in Seward) has trails around Exit Glacier, and info on tour boats into the fjords.

The AK Public Lands Information Centers also have info on other public lands, www.alaskacenters.gov

You can also find us on Facebook, AlaskaNPS

Have a great trip!