National Parks Traveler

Within park boundaries exists the nation's largest glacial system, with glaciers covering 35 percent of the parklands. Some glaciers do not look pristine like you might picture them. Those brown lines you see in the photo are medial moraines. According to the National Park Service:

Medial moraines form where two tributary glaciers come together. They are generally surficial features on the ice and often consist of rock that has fallen from a rockwall where the glaciers converge. Because they are thin, surficial features, medial moraines are rarely preserved after the ice retreats.

The Great Kobuk Sand Dunes in Kobuk Valley National Park are the largest active sand dunes in the Arctic. Along with the smaller Little Kobuk Sand Dunes and Hunt River Sand Dunes, the Great Kobuk Sand Dunes create 30 square miles (77.7 sq km) of towering sand 35 miles (56 km) above the Arctic Circle. 

Some 3,000 feet (914 m) below Mount Katmai and encroaching into the Valley of Ten Thousand Smokes are the Knife Creek Glaciers, covered with as much as 6 feet (2 meters) of ash and pumice. Hikers can walk right up to the foot of, and even onto the glaciers, if they wish (with caution).

Many rivers flow through the stunning mountainous landscape of Gates of the Arctic National Park and Preserve, including six national wild and scenic rivers: Alatna River, John River, Kobuk River, Noatak River, North Fork of the Koyukuk River, and Tinayguk River.

Take a helicopter ride over active volcanics in Hawai'i Volcanoes National Park and you might just see a bright "eye" of lava looking at you through a lava "skylight" - an opening in the roof of a lava tube through which red-hot lava is flowing. You can learn about volcanic terms you might come across during a visit to this national park by reading this Hawai'i Volcanoes Primer. You  can also read more about magnificent volcanic action by reading the Traveler article In Awe Of Pele's Force.

The discovery of Lehman Caves eventually led to the establishment of Lehman Caves National Monument, which in turn led to the establishment of Great Basin National Park in Nevada. Lehman Caves, like Jewel Cave in South Dakota, is filled with amazing, whimsical, and intricate speleothems (cave formations). You can read about Lehman Caves by clicking here.

Acadia National Park in Maine is another one of those units of the National Park System famous for it's fall foliage colors. You can learn more about what you might see during different seasons at Acadia by clicking here.

Gypsum "flowers" are a speleothem (cave formation) that form when thicker gypsum crystals form and grow outward from the cave walls. They often form curved or flower-petal-like shapes. To learn more about speleothems at Jewel Cave, click here.

146 years ago today, just before dawn, gunshots rang out throughout the peaceful valley of ?ıckumcılé.lıkpe (Big Hole Valley), startling awake a sleeping camp of 800 nimí·pu· (Nez Perce). Hatalekin, an elder setting out to check upon his herd of horses, had been shot down by a group of Bitterroot civilian volunteers. Thus began the Battle of the Big Hole, wherein 60-90 nimí·pu·—largely women and children—and 31 soldiers and volunteers were killed. Big Hole National Battlefield in Montana was created to honor all who were there.