Ajo Mountain Drive Stop 2

The aroma of creosote defines the Sonoran Desert for many.

NPS Photo/ Craig Stocks

Quick Facts

Location:

Mile 1.4 [km 2.3] along the Ajo Mountain Drive

Stop 2

The Desert Smells Like Rain

Decorating the landscape of the Sonoran Desert is the creosote bush. This olive green shrub you see all around you is one of the most drought-tolerant plants in North America. Long after the soil is too dry for most species, creosote still manages to absorb water. Its adaptations allow it to survive without water for two years before completely dying. 

This supple plant sports small yellow blossoms in the spring and summer. It may occasionally bloom during other times of the year if rainfall is sufficient. The seeds are gray fuzzy balls that resemble droplets of water hanging from the branches. The waxy coating on creosote’s leaves protects the plant from excessive water loss. Locals often say that the Sonoran Desert “smells like rain” because of the intoxicating aroma the leaves give off during a rain storm or on a foggy winter morning. 

Creosote is found abundantly, all over the southwest, in three deserts – the Chihuahuan, Mojave and Sonoran. It also is very long-lived, creating clonal colonies; one found in California is believed to be over 10,000 years old and is considered one of the oldest single living organisms on the planet. 

Creosote is useful to many desert species. The kangaroo rat likes to build its nest within the roots of the creosote bush. The seeds are a life source to many jackrabbits. The desert kit fox prefers to make its den within the roots of the creosote. Many cactus species use the
creosote for shelter when the cactus is young and establishing its own root system.

This unassuming shrub originated in South America but it is clearly one of the most well-adapted plants found in the monument. The creosote has not only made its home in the heart of the Sonoran Desert but in the hearts of many desert natives as well.