top left: The Dead River is so named because it disappears into sand at the south end. Biologically it is very much alive.
top right: yucca is prevalent at the south unit (so is prickly pear cactus, but I didn't get a photo)
bottom left: juniperis horizontalis waukeganensis
-- a very localized subspecies of creeping juniper
bottom right: that's one meter square, used to measure plant density
Several movies were made here years before the park was officially created.