Organ Pipe Cactus National Monument, Arizona, USA

A couple Organ Pipe Cacti at the beginning of the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA. In 1976 the monument was declared a Biosphere Reserve by UNESCO.

Organ Pipe Cactus National Monument, Arizona, USA

Branchless saguaro flanked by two Organ Pipe cacti along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA.

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA. In 1976 the monument was declared a Biosphere Reserve by UNESCO.

Organ Pipe Cactus National Monument, Arizona, USA

Although it's called Organ Pipe Cactus National Monument, Saguaros dominate the scene in most areas of the park. In fact the saguaro cactus (Carnegiea gigantea) is one of the defining plants of the Sonoran Desert.

Organ Pipe Cactus National Monument, Arizona, USA

Saguaros along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Saguaro Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona

Organ Pipe Cactus National Monument, Arizona, USA

Chain fruit cholla, Saguaros and creosote bush dominate the landscape along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA.

Organ Pipe Cactus National Monument, Arizona, USA

Saguaros along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Tall Saguaro Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Saguaros along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Cholla cactus and Saguaros at the twin peaks along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cacti and Saguaros at the Twin Peaks along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Saguaro Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cacti and Saguaros along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cacti and Saguaro along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus (Stenocereus thurberi) surrounded by Chollas along the Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA.

Organ Pipe Cactus National Monument, Arizona, USA

Teddy-bear cholla (Cylindropuntia bigelovii) along the Ajo Mountain Loop Drive in Organ Pipe Cactus National Monument.

Organ Pipe Cactus National Monument, Arizona, USA

Teddy-bear cholla (Cylindropuntia bigelovii) along the Ajo Mountain Loop Drive in Organ Pipe Cactus National Monument.

Organ Pipe Cactus National Monument, Arizona, USA

Cholla Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA.

Organ Pipe Cactus National Monument, Arizona, USA

Cholla Cactus field along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA.

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cacti and Saguaros along North Puerto Blanco Drive in Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA. In 1976 the monument was declared a Biosphere Reserve by UNESCO.

Organ Pipe Cactus National Monument, Arizona, USA

Organ Pipe Cactus along the North Puerto Blanco Drive at Organ Pipe Cactus National Monument in southern Arizona, USA. In 1976 the monument was declared a Biosphere Reserve by UNESCO.