National Parks Centennial

Yosemite National Park, which encompasses nearly 1,200 square miles, was first protected in 1864 and designated a national park in 1890. // © 2016 Insight Vacations

Glacier National Park offers trekkers more than 700 miles of trails through Montana's Rocky Mountains. // © 2016 Yankee Holidays

Canyonlands National Park in Utah displays some of the area’s buttes carved by the Colorado River. // © 2016 Insight Vacations

Bryce Canyon National Park’s hoodoo rock formations are another illustration of Utah’s fantastical scenery. // © 2016 Tauck

In Colorado’s Mesa Verde National Park, visitors can see 600 cliff dwellings of the Ancestral Pueblo people that date back to 600 A.D. // © 2016 Insight Vacations

Visitors will find two distinct desert ecosystems, the Mojave and the Colorado, in California’s Joshua Tree National Park. // © 2016 iStock

Yellowstone was the world’s first national park, established in 1872. // © 2016 Tauck

Sequoia National Park in California is home to towering sequoia trees. // © 2016 iStock

Grand Canyon National Park features a canyon that is 277 river miles long, up to 18 miles wide and 1 mile deep. // © 2016 Insight Vacations

Kentucky’s Mammoth Cave National Park preserves the world's longest known cave system. // © 2016 iStock

Arizona’s Saguaro National Park is one of America’s more recent parks, established in 1994. // © 2016 iStock

Ground squirrels are common in many U.S. national parks. // © 2016 iStock

Send history buffs to Gettsyburg National Military Park in Pennsylvania. // © 2016 Tauck

Visitors to Grand Teton National Park in Wyoming can explore the alpine terrain of the Teton Range, more than 200 miles of trails and the Snake River. // © 2016 iStock