Updated

Chilean President Michelle Bachelet and Tompkins Conservation are signing an agreement to donate 1 million acres for new national parks in the largest private donation of its kind to the South American country.

Bachelet signed the agreement Wednesday with Kristine McDivitt Tompkins. She is the widow of American conservationist Doug Tompkins, who built a legacy protecting threatened ecosystems in Argentina and Chile.

The agreement will provide land to create three new national parks, expand three existing national parks and unite some national forests into two national parks.

In all, the plan ultimately seeks to increase Chile's national parkland by more than 10 million acres. Tompkins Conservation says the area that will be protected is three times the size of the United States' Yosemite and Yellowstone national parks combined.