In 1977 the state was split into two halves, with Mato Grosso do Sul becoming a new state. The Bororo Indians live in the Mato Grosso area. As late as 1880, soldiers patrolled lands on the outskirts of Cuiaba, Mato Grosso's capital and largest city, to protect settlers from Bororo raids.

By the end of the nineteenth century, although severely reduced by disease and by warfare with explorers, slave traders, prospectors, settlers, and other indigenous groups, as many as five to ten thousand Bororo continued to occupy central and eastern Mato Grosso, as well as western Goias.

The historic remoteness of this area led it to be the subject of exploration, most notably by Captain Percy Fawcett, in the quest for lost cities. It was also the rumored location of access to the interior of the earth in various Hollow Earth theories.