

Fig. 1Organ pipe cactus under the Ajo Range
Landform
The United States’ only big stand of organ pipe cactus, under the Ajo Range. Sonoran desert at the Mexican line.
Field note
Stenocereus thurberi is common in Mexico and rare here. The Ajo Mountains are a red wall at sunset. Ajo is the last town. This is the desert Saguaro’s quieter, southern cousin.














