Two deserts, two large ecosystems whose characteristics are determined primarily by elevation, come together at Joshua Tree National Park. The Colorado Desert encompasses the eastern part of the park and features natural gardens of creosote bush...

Maine ocean islands provide the only nesting sites for Atlantic puffins in the United States. Eastern Egg Rock in the midcoast region, Seal Island and Matinicus Rock at the mouth of Penobscot Bay, and Machias Seal Island and Petit Manan Island off the downeast coast provide habitat for more than 4,000 puffins each summer.