 The elevation above sea level is about .The name of the region dates to the time of Marechal Cândido Rondon, who noticed a large amount of native cocao there near the bank of the Ji-Paraná River (Machado River).He recommended that the guard Anízio Serrão build a house there, and Serrao asked for the site to be granted to him in 1912, calling it Cacoal.