Complex sentence: Further, Symmes sold much land that he did not own, some as far north as Dayton, meaning some early settlers found themselves squatters on the public domain, and sold some land that he did own more than once.
Split into simpler sentences: Further, Symmes sold much land that he did not own, some as far north as Dayton, meaning some early settlers found themselves squatters on the public domain. Symmes also sold some land that he did own more than once.