Yellowstone National Park isn't the only national park with bison issues. Far to the south, Grand Canyon National Park officials are trying to better manage bison on the park's North Rim. Actually, they're trying to get the animals off the park's property on the North Rim.

Rebels with a Cause, a documentary that celebrates the people and passion that saved the coastal wonders that would become the Point Reyes National Seashore and the Golden Gate National Recreation Area, is airing on PBS stations this month.

Rivers run fast and tumbling throughout the National Park System, there are streams with lazy meanders, and placid lakes perfect for dipping a paddle. This diversity poses a delightful dilemma when you have the urge to float and paddle. What follows is just a sampling of the experiences that await you, whether you have hundreds of watery miles under your paddle, or are looking for calm waters to take your youngsters.

Climate change. Glaciology. Sustainability. These are not the subjects that leap to mind when you consider sending your kids to summer camp. But blend them with backpacking, canoeing, or a walk in the woods, and the result is a generation with not only a better connection with nature, but perhaps a career path.