 Not until the 1870s was a road fashioned across the northern Chaco from Santa Cruz to Corumbá Brazil.Located on the frontier between Portuguese Brazil and Spanish Paraguay, the Mbayá also raided the Portuguese, although they made peace with them in 1791.Ranchers in Paraguay in 1796 killed 300 Indians, including eleven Mbayá chiefs, thus breaking the long-standing peace agreement between Mbayá and Paraguayans.