Kept open by periodic fires that limit growth of grasses and forbs in shallow soil, glades are home to collared lizards, tarantulas, scorpions, cacti and other species more typical of the desert southwest.
The Boston Mountains contain the highest elevations of the Ozarks with peaks over 2,500 feet (760 m) and form some of the greatest relief of any formation between the Appalachian and Rocky Mountains.
Drainage is primarily to the White River, with the exception of the Illinois River, although there also is considerable drainage from the south slopes of the Boston Mountains to the Arkansas River.
Major streams of this type include Lee Creek, Frog Bayou, Mulberry River, Spadra Creek, Big Piney Creek, Little Piney Creek, Illinois Bayou, Point Remove Creek, and Cadron Creek.
The large, top most arc or bend in this part of the Arkansas River was referred to as the aux arcs—the top or most northern arc in the whole of the lower Arkansas.