Complex sentence: Tom Patterson, a local Riverside historian, suggested that the original name of Mount Rubidoux was Pachappa, and one of the early owners of Rancho Jurupa assigned the name Pachappa to another smaller hill, in order to expand the property of the Rancho.
Split into simpler sentences: Tom Patterson, a local Riverside historian, suggested that the original name of Mount Rubidoux was Pachappa. He speculates that one of the early owners of Rancho Jurupa reassigned the name Pachappa to another smaller hill, in order to expand the property of the Rancho.