Nestled among the Little San Bernardino Mountains, the desert oasis at Big Morongo Canyon is one of the 10 largest cottonwood and willow riparian habitats in California. The preserve is an internationally-recognized birding site. Several rare or unusual species are known to nest here, and many other species are abundant during the spring and fall migration seasons. The lush vegetation of Big Morongo Canyon stands in sharp contrast to the surrounding desert slopes. A high water table in the canyon has made the growth of tall trees possible, despite the desert climate. The area is of botanical interest because it includes two desert vegetation zones: the Mojave and the Sonoran. The Preserve is home to a number of mammals, including mule deer, desert bighorn sheep, raccoons, bobcats, coyotes, and kangaroo rats and other rodents.
