Bioregionally it is the Sonoran Desert, northern Sierra Madre Occidental, and all of the Madrean Sky Islands. It also encompasses most Sinaloan thorn-scrub, Apache Highlands, some Chihuahuan Desert, and the northern extents of TDF.
This is a highly diverse region on a planetary scale, harboring everything from extremely hot and dry sand dune ecosystems, through plains grasslands, mangrove estuaries, tropical drought-deciduous forest, and mixed-conifer forests.
There are political lines that bisect our region, but Wild Sonora generally tries to ignore them, except when their effects cannot be ignored, eg. the border wall.
You can use this map as a general reference to areas covered by Wild Sonora.