Snowmobiles, off-road vehicles, and personal watercraft are perhaps the most polarizing recreational issues within the national park system. In this guest column, the specter of greater ORV access in Big Cypress National Preserve's Bear Island Unit is examined.

Rooted in the "River of Grass' that once was the dominant landmark in south Florida, Everglades National Park is in a state of flux due to environmental pressures.

There are parks across the national park system that have decidedly watery settings: Voyagers National Park, Isle Royale National Park, Channel Islands National Park, Acadia National Park, Biscayne National Park and Dry Tortugas National Park, just to name some of the most obvious. And then there are the national lakeshores.

With time running out, Congress has yet to commit to funding the president's Centennial Challenge for the National Park Service. While the House has committed $50 million towards the campaign, the Senate has not provided any funding.