Rocky Mountain National Park – Colorado

Though it only gets about a half to two-thirds of the visitors that Yellowstone gets, RMNP is a must-see destination for wildlife lovers and nature photographers.

The 415-square-mile park rises from 8,000 to 14,000 feet, and includes more than 300 miles of hiking trails through both alpine and sub-alpine habitats.

Here you’ll find around 67 mammal and more than 200 bird species, including threatened and endangered animals.

Budding or amateur lepidopterists can try to spot any of the 141 confirmed butterfly species, including the Silvery Checkerspot and the Juniper Hairstreak.