After the war, Tolosa led several expeditions in search of silver along with Miguel de Ibarra and a contingent of Spanish soldiers and Indian slaves.
[5] Tolosa also claimed credit for discovering rich deposits of silver at San Martin, Sombrerete, and Avino 115 miles north-west of Zacatecas in 1556.
In 1594, his children and other witnesses claimed that he had died in poverty, spending the fortune he had made in Zacatecas on expeditions to find new mines.
[10] In 1576, a Matías de Tolosa, requested an emigration licence in order to assist his "rich brother Juan" in New Spain.
The request is accompanied by a letter written from Acapulco which informs us of a good personal network by Juan which makes an identification likely.