In this period the mine was amongst others instrumental in the establishment of a hydro-electrical power plant, a state of the art hospital, the Villa Nova AC association football team, which had some importance between the 1930s and 1970s and the construction of a circa 10 kilometre tramway line between Nova Lima and Raposos, considered the first in South America.

In 1975 the South Africa-based Anglo American Corporation, a precursor to today's AshantiGold, became owners of the operations.

Although Morro Velho's main production is gold, silver, arsenic, and other minerals are also extracted at the mining complex.

Despite closing of the Minha Velha and Engenho D'Água mines in 2003 and 2004, gold production has increased over the past three years, with 240,000 ounces (6,800 kilograms) of gold produced in 2004 at an average recovered ore grade of 0.222 ounces per ton (7.62 grams per metric ton).

Cash costs of production totalled $133 per ounce, with the mine realizing adjusted operating profit of $45 million.