One of the "crown jewels" of the national park system will celebrate its centennial in 2010, and when you're talking about planning a celebration of that magnitude, there's plenty of work to do. Glacier National Park is off to a great start in that regard, and you may want to know about upcoming deadlines for some activities that are already underway.

Yellowstone National Park is scheduled to open its winter season on Monday, and a storm forecast for this weekend could give the park a big boost in terms of snow cover. Without additional snow, the season might open without enough of the white stuff for snowmobiling.

You won't find many long-distance hikes in Death Valley National Park, which probably is a good thing considering how hot it can get during the summer months. But for those looking to stretch their legs, the trail through Golden Canyon is viewed by many as the "to-do" hike in the park.

There's mixed news today on the environmental front. On one hand, the Bush administration has pulled back a proposal that would weaken air quality rules for coal-fired power plants. But on the other it has moved forward with a rule to weaken the Endangered Species Act.