To prevent ugly scarring of the ridgeline during the construction of Skyline Drive in Shenandoah National Park, workers instead blasted away 670 feet of solid rock through a mountain to create Marys Rock Tunnel, considered an engineering marvel of its day. 

Located at mile 4.6 in the northern part of Shenandoah National Park, the Dickey Ridge Visitor Center offers visitors not only the chance to learn about the park and get their questions answered, but also to just sit a spell on a sunny day and enjoy the Shenandoah Valley vista.

Sunrises and sunsets are sublime over the ancient, rounded Blue Ridge Mountains as seen from the 75 different overlooks within Shenandoah National Park.

Walk along Kalaloch Beach not to far from the Kalaloch day parking area and you will see the strange sight of a Sitka spruce with its roots precariously balancing on either side of the walls of a cave-like depression hollowed out by running water. This tree is called the "Tree of Life" and its location is often referred to as the "Tree Root Cave." Someday, this tree will fall to the beach, but for now, it's hanging in there.

Endemic to the six largest islands of Hawai’i, the ‘Ōhi‘a lehua is the most common native Hawaiian tree, comprising 80 percent of Hawaii’s native forests. It's one of the first things to start growing on a fresh lava flow.

Believe it or not: Joshua trees are not botanically classified as trees. They look like trees and have what appears to be woody bark, but are are giant succulents belonging to the Agave family (Asparagaceae) closely related to lilies.

Hike the popular Sol Duc Falls trail in Olympic National Park and you'll find yourself wandering through a temperate rainforest filled with towering Douglas fir, Western hemlock, Sitka spruce, Western red cedar, and maple trees, to name a few.

Bristlecone pines are among the oldest trees in the world, with some having reached the age of 5,000 years. At Great Basin National Park, you can hike to a grove of bristlecones growing beneath the towering Wheeler Peak.

While not the tallest trees in the world, giant sequoias are the largest trees in the world by volume, with an average base diameter of 20-26 feet (6-8 meters) upon reaching maturity.

Drive the Tioga Road in Yosemite National Park and you will see Jeffrey pines like this one with roots growing in granite fractures where the rock breaks down to form soil and water collects to create an environment suitable enough for hardy vegetation to grow.

Coastal redwood trees are among the tallest trees in the world and grow only along a 450-mile stretch of the foggy California-Oregon coast.

The Swiftcurrent Lake Nature Trail located in the Many Glacier area of Glacier National Park in Montana is a mostly-flat 2.7-mile (4.35-kilometer) loop trail around Swiftcurrent Lake, with views of the Many Glacier Hotel, mountains, forests, and meadows.

Conveniently located right next to the Sunset Point overlook at Bryce Canyon National Park, the Navajo Loop Trail is a 1.3-mile (2.1-kilometer) trail. According to Park Staff: "... Switchbacks wind between narrow walls of colorful limestone with views of towering Douglas-fir trees and the park's most famous hoodoo: Thor's hammer. The loop has two sides: Two Bridges and Wall Street. The Two Bridges side is open year-round, however, the Wall Street side is closed during the winter months. During this time Two-Bridges can be hiked as an out-and-back trail or combined with other trails."

In addition to some amazing red rock arches and other sandstone formations, Arches National Park in Utah is home to all sorts of wildlife, including mule deer.

Pipestone is a metamorphosed red or black mudstone considered sacred by Indigenous people and carved into pipes used for prayer and ceremonies. It is found in seams among the much harder Sioux Quartzite and is mined by hand.

Pine Creek Trail is one of several trails you can hike at Curecanti National Recreation Area in Colorado. This trail is 2.6 miles (4.2 kilometers) roundtrip and is considered a moderate hike.

Many, if not most of the 200 prehistoric mounds at Effigy Mounds National Monument in Iowa are in the shape of an animal, such as this mound here, in the shape of a bear.

Why did the bison cross the road?

The Island Trail is a 0.9-mile (1.45-kilometer) round trip trail that descends into the canyon to view a series of cliff dwellings. It is rated as strenuous and contains 736 stairs. The Island Trail closes daily at 4:00 p.m. and the Rim Trail closes at 4:30 p.m.

According to Park Staff: "The "wild" horses on Assateague are actually feral animals, meaning that they are descendants of domestic animals that have reverted to a wild state ... The horses are split into two main herds, one on the Virginia side and one on the Maryland side of Assateague. They are separated by a fence at the Virginia/Maryland State line. These herds have divided themselves into bands of two to twelve animals and each band occupies a home range."