Rain in the Sonoran Desert

St. David Cienega on San Pedro NCA

Magnificent view of the Whetstone Mountains from the Cienega parking lot:
Numerous springs in the Cienega and along the San Pedro:

Beautiful Cienega with grasses and rushes:


The San Pedro goes dry along here. Note the extensive tamarisk infestation, with cottonwoods in the background:
The Cienega can be almost impenetrable:

Wilcox Playa - Sandhill Cranes

Aravaipa Canyon: Search and Destroy the Mother Tamarix

The objective of this project was to survey and map the extent of the invasive genus Tamarix (Salt Cedar, Tamarisk) in Aravaipa Canyon, a federally-designated wilderness area in AZ managed by BLM. Aravaipa canyon, if it were not a wilderness area, would make a great National Park, with its lush riparian forest surrounded by pinon-juniper woodland grading to Saguaro cacti. After a large flood in 2002, the streambed morphology and vegetation structure of the canyon were radically altered, opening room for recruitment of non-native Tamarix, in addition to naturally occuring cottonwood and willow.


Building upon previous volunteer efforts, I spent a week in the canyon taking notes on the prevalence, preferred-habitat, age-class, and GPS location of Tamarix colonies. I was able to identify pre-flood "mother" Tamarix that were responsible for seeding in new colonies. Based upon the distribution of old and new individuals, it is possible to get some idea of the rate and extent of this invasion. These data are arailable upon request.

A mother Tamarix.

Verde River Explorations

The Verde River and its tributaries in central AZ present a fascinating example of a naturally regenerating ecosystem. Grazing was removed almost 20 years ago and today the trees in the riparian forest are all ~20 years old.
Clear Creek, AZ, a tributary of the Verde.

Some trees are loosing their leaves, while other plants are flowering.
A dry tributary of the Verde.
Wild and Scenic portion of Verde River: mountains constrict its flow here.
An island in the Verde: like being at the beach, but more green.

Tent rocks formation along USFR 500
Page Springs: two large blue herons just flew off



Sycamore Canyon Springs and Wilderness Area, a tributary of the Verde.



Tuzigoot National Historic Site, overlooking Verde River.

Southern Arizona's Ranching Heritage

North Canyon Transect Wildlife Tracking

For Sky Island Alliance, a dedicated group of volunteers document animal activity every six weeks throughout the Southeast corner of Arizona. This citizen science project, a vanguard for others, yields invaluable natural history presence/absence data. These photos are from our North Canyon Transect, in Las Cienegas National Conservation Area.

Climbing Dutchwoman Butte, AZ

From Dutchwoman Butte

Dutchwoman Butte is one of the few, original, intact wilderness areas in the country that have never been grazed by domestic livestock. The Butte, or mesa, is ringed all about by high cliffs...

From Dutchwoman Butte

Its base floats in a sea of Sonoran desert cacti, while its high flatlands support a lush grass-and-wildflower community.

From Dutchwoman Butte

Crucifixion thorn is a prominent shrub. While Agave stalks shoot up individually-unique pastels.

From Dutchwoman Butte