Today, the land is dotted with mesquite trees that have spread through the valley over the past century due to suppression of natural fires. Yet this is still a place of long vistas, rolling hills flanked by purple mountains, and spectacular sunsets over Baboquivari Peak.
Mule deer and pronghorns still roam the flat plain and rolling hills. Though the Mexican gray wolf and magnificent grizzly bear are long since gone, at home on the refuge are coyotes, foxes, bobcats, javelina, four types of skunks and two kinds of jackrabbits. The diverse array of reptiles includes rattlesnakes, desert tortoises and occasional Gila monsters.
At the east side of the refuge areareas along Arivaca Creek and Arivaca Cienega. Here there is a delightful mix of seasonally wet marshland and meadow, stately cottonwoods, and hackberry and mesquite groves. These wetlands are rare in the dry Southwest and are of tremendous value to wildlife.
In the leafy green oasis is the ruby-red glow of summer tanagers or vermilion flycatchers, the oriole’s liquid melody, and the plaintive whistle of the gray hawk. Here, lucky birders may find subtropical specialties at the northern end of their species range: Gray hawks and black-bellied whistling ducks are regularly seen. Tropical and thick-billed kingbirds are possible, and even a green kingfisher or northern beardless tyrannulet are occasionally sighted.
Beautiful Brown Canyon flanks the west side of the refuge in the foothills of the Baboquivari mountains. Here a sycamore-lined stream meanders under live oaks. Although dry much of the year, the stream at other times gurgles under the trees while filling rock pools. At the cooler elevations of four to 5,000 feet, Coues white-tailed deer take the place of the mule deer found in the lower valley. This is also where the ringtails and coatimundis, members of the raccoon family, reside. This rugged country is habitat for mountain lions and javelina and may harbor an occasional wandering jaguar from Mexico.