These parks are incredibly beautiful and a joy to experience, and it is our responsibility as park visitors to keep them that way. Don't feed the animals. Don't litter. Don't take anything home that you didn't buy or bring with you. Share trails and walkways, and stay on them. If this sounds like something you learned in grade school, it is, but sometimes people need a gentle reminder that 50 million years of work deserves respect.

It's relatively easy to be a good outdoor citizen -- it's mostly common sense. Pack out all trash, stay on established trails, be careful not to pollute water, and do your best to have as little impact on the environment as possible. Some hikers go further, carrying a small trash bag to pick up litter. As the park service likes to remind us, protecting our national parks is everyone's responsibility.

Nonetheless, heavy summer auto traffic and the annual impact of millions of human beings have raised questions about the sustainability of these national parks. But a visit to Yosemite and Sequoia & Kings Canyon can still be a relatively green vacation. In Yosemite, concessionaire DNC Parks & Resorts at Yosemite (tel. 801/559-4884; has implemented numerous environmental initiatives, including a recycling program, non-native plant-removal initiatives, and biodiesel-powered vehicles. Campgrounds have recycling bins near the entrances.

Perhaps the best way to think about sustainability is by connecting with the parks' wild soul via hikes on the trails and overnights in the campgrounds. One of the best ways to lessen one's impact is to go off the grid on an overnight backpacking trip. Backpacking is a refreshing counterpoint to modern life that will give perspective on the issues of sustainability and personal energy dependence. See Leave No Trace ( for more on the backpacker's ethic to leave any campsite in the same condition -- or better -- than when you found it.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.