Once seen as an innovative project for its time, in 1929, Tamiami Trail was built along the northern edge of what was to become Everglades National Park and through Big Cypress National Preserve. It fulfilled the dream to create passage across the Everglades from Tampa to Miami. Today, many people feel much differently about the road that currently impedes the natural flow of water through the historic River of Grass.

If the winter of 2008-09 is as severe as this slowly retreating winter, will it matter that 25 Yellowstone National Park bison have been saved from slaughter while another 1,200 or so are trucked to their death? Those paying $2.8 million to gain grazing rights to a ranch just north of Yellowstone think so.

Mountain snows slowly are beginning to melt, the aspen are beginning to unfurl their leaves, and the bears are rummaging about. All the more reason to pay attention to not just your surroundings in the national parks, but your cleanliness in terms of food.

National Park Week is being celebrated this year from April 20 through April 26. Across the system there are dozens, if not hundreds, of special events planned. Here's a look at some of them.