Nearly 2 million acres of private land within the boundaries of U.S. national parks is at risk of being developed if it isn’t purchased by the federal government soon, according to a report from the National Parks Conservation Association. Some 4.3 million acres of private land lie within park boundaries, 1.8 million acres of which are considered high priority purchases and could be acquired for a total of about $1.9 billion. The NPCA is calling on Congress and the next U.S. administration to fund the acquisitions before the park service’s centennial in 2016 and before the private landowners decide to develop their property. “People who use and visit national parks will be surprised to learn a lot of land within national park boundaries is not protected,” said Ron Tipton of the NPCA. “It’s not a pretty story that we have park lands that are threatened, for sale and that there is no money to do anything about it.”