Prairie restoration is a type of habitat conservation, for prairies and habitats that lived alongside prairies. It is the act of restoring land that was once native prairie to how it once was. In North America this is usually defined as "pre-settlement", meaning before Europeans arrived. Much of this land is good for farming and has been plowed for planting crops or turned into pastures. In Illinois, there was once 22 million acres (9 million hectares), now there are less than 2300 acres (920 hectares) of high-quality original prairie remaining.