Simplify the following text for a Grade 4 native English-speaking person.
Original: The name `` Mato Grosso do Sul '' literally means `` Thick Forest of the South '' in Portuguese , a name inherited from its northern neighbor state of Mato Grosso , of which it was part until the 1970s .
Simplified: Mato Grosso do Sul means `` Southern Thick Forest '' . The name comes from its northern neighbor state of Mato Grosso .