This text is missing some spaces, please add them: TheybecameknownastheAthabascanIndians,abranchofwhichmigratedsouthtobecomethepeopleknownastheApachesandNavajos(ApachesdelaNavahu).
They became known as the Athabascan Indians, a branch of which migrated south to become the people known as the Apaches and Navajos (Apaches de la Navahu).