ALBANIA, Colombia – Coal miner Cerrejon has financed the reforestation of a large swath of land in northern Colombia that was left desolate by decades of mining activity.

Cerrejon, owned in equal parts by BHP Billiton plc, Anglo American plc, and Glencore plc, holds a 50-year concession to exploit La Mina, a spread of 69,000 hectares (170,370 acres) that is the world’s largest open pit coal mine.

Mining operations began in 1984 in the area known as Tajo Oeste, leaving behind a giant crater more than 100 meters (328 feet) deep.

The mining company filled the pit with uncontaminated soil, topped by a cap of vegetation to give life to a tropical forest.

“The issue of land rehabilitation is one of the elements where Cerrejon is a pioneer and something of an international leader,” company President Roberto Junguito Pombo told EFE.

So far, the reforested area comprises 3,552 hectares of native flora and fauna and attracts more than 6,000 tourists each year.

Iguanas, rabbits, birds, deer and “even two jaguars” have been spotted in the area, tour guide Joicy Romero said.

The company retains the topsoil from all areas where mining activity begins and has a group of environmental experts to do soil research and reforestation efforts.

Mining continues across roughly 6,000 hectares of La Mina, producing around 90,400 tons of coal per day for export to Europe, the U.S. and Asia.

Once the mining operations ends, Cerrejon plans to reforest the rest of the territory.