Organ Pipe Cactus National Monument

Organ Pipe Cactus National Monument protects over 520 square miles of Sonoran Desert in southwestern Arizona, home to many cactus species and wildlife. The area features a network of hiking trails and campgrounds that allow visitors to explore the desert landscape firsthand.

Arizona's legislature donated the land to the federal government during Prohibition, and it became a national monument in 1937. This designation protected this unique desert area from commercial development and preserved it for future generations.

The land borders the Tohono O'odham Reservation and reflects centuries of indigenous presence through archaeological remains and traditional routes. Visitors walking these paths can sense the deep connection between the landscape and its original inhabitants.

Access is via Puerto Blanco Drive from State Route 85, with clearly marked trails for different fitness levels. Visitors should bring plenty of water and sun protection, as desert sun is intense.

It is the only place in the United States where senita and organ pipe cacti grow together in their natural desert setting. This rare combination makes the area botanically significant and especially interesting for cactus researchers.

Location: Pima County

Inception: April 13, 1937

Operator: National Park Service

Part of: Western Arizona

Shares border with: Ajo

Website: https://nps.gov/orpi

GPS coordinates: 31.95400,-112.80095

Latest update: December 20, 2025 13:17