Alex Demas (Former Employee)

A small creek drains into the Potomac River in Piscataway Park, south of the District of Columbia.

An osprey sits in a tree near its nest in Piscataway Park, just south of the District of Columbia

An osprey's nest in Piscataway Park, just south of the District of Columbia. The osprey sits just to the right of the nest.

An osprey's nest in Piscataway Park, just south of the District of Columbia.

A tree stump has been weathered away by tidal action into this unique shape. The stump lies on the shores of the Potomac River in Piscataway Park, just south of the District of Columbia.

A small creek drains into the Potomac River in Piscataway Park, south of the District of Columbia.

A panorama of Accokeek Creek in Piscataway Park, south of the District of Columbia.

The mouth of Accokeek Creek as it empties into the Potomac River in Piscataway Park, south of the District of Columbia.

Driftwood along the banks of the Potomac River in Piscataway Park, south of the District of Columbia.

Driftwood along the banks of the Potomac River in Piscataway Park, south of the District of Columbia.

The Chimney Rock formation with Catoctin Moutain Park. Catoctin Mountain is part of the Blue Ridge Mountains. Chimney Rock is mostly made of quartzite, a metamorphic mineral.

A panorama of the Chimney Rock formation with Catoctin Moutain Park. Catoctin Mountain is part of the Blue Ridge Mountains. Chimney Rock is mostly made of quartzite, a metamorphic mineral.

A hiking trail winds through the woods of Catoctin Mountain Park towards the Chimney Rock formation. Catoctin Mountain is part of the Blue Ridge Mountains.

A panorama of the Chimney Rock formation with Catoctin Moutain Park. Catoctin Mountain is part of the Blue Ridge Mountains. Chimney Rock is mostly made of quartzite, a metamorphic mineral.

The Chimney Rock formation with Catoctin Moutain Park. Catoctin Mountain is part of the Blue Ridge Mountains. Chimney Rock is mostly made of quartzite, a metamorphic mineral.

The Chimney Rock formation with Catoctin Moutain Park. Catoctin Mountain is part of the Blue Ridge Mountains. Chimney Rock is mostly made of quartzite, a metamorphic mineral.

This tree is known as the Fallen Monarch Tree. It fell roughly 300 years ago. Because of the high level of tannins in their bark, giant sequoias are resistant to decay.

In this image, Bridalveil Fall can be seen from Tunnel View in Yosemite National Park. The waterfall is 617 ft (188 m) in height and is one of the most well-known of Yosemite National Park's waterfalls.

This stand of giant sequoia trees is known as the Bachelor and Three Graces. They are located within the Mariposa Grove of Big Trees in Yosemite National Park.

In this image, the tunnel through the California Tunnel Tree may be seen. The tunnel was cut through the giant sequoia tree in 1895 to allow coaches, and eventually cars, to drive through the tree as part of a marketing stunt. The California Tunnel Tree is the only living giant sequoia with a tunnel cut through it. 

In this image, the west face of El Capitan may be seen from Tunnel View. El Capitan is a granite monolith that rises about 3,000 ft (900 m) from the valley floor and is one of Yosemite National Park's most famous landmarks.