Yosemite National Park announced yesterday that it's growing by 400 acres, The New York Times reports. Though that's not a lot of land for a park that totals 1,169 square miles, the expansion is significant because it includes wetlands — key environmental areas that improve water quality, provide habitats for wildlife, and store water in times of droughts.

The new addition, the park’s largest expansion in 67 years, is called Ackerson Meadow. The area was donated to the park by The Trust for Public Land, a nonprofit conservation organization that purchased Ackerson Meadow for $2.3 million earlier this year. That money was in part also provided by the nonprofit Yosemite Conservancy and the National Park Trust.

"The generous donation of Ackerson Meadow will preserve critical meadow habitat that is home to a number of state and federally listed protected species," Don Neubacher, the superintendent of Yosemite National Park, said in a statement.

The meadow is a very valuable piece of land — and a rare one too for the park. Only 3 percent of the entire park’s area is made of meadows, the park service said in a statement. Yet, meadows may be home to one-third of all the plant species found in the park. "Most of San Francisco’s water is filtered by Yosemite’s meadows, including Ackerson Meadow," the park service said.