The Nature Conservancy. Kiosk and information pamphlets at parking area. With less than one-tenth of one percent of native Illinois prairie remaining, Nachusa Grasslands provide an opportunity for people to enjoy a part of this rare ecosystem. Encompassing over 2,800 acres, the Grasslands are comprised of sandstone outcrops, rolling hills, oak savannas, wetlands and, of course, a virtual sea of bluestem prairie. Activities such as hiking, photography, and bird watching are encouraged. Nachusa Grasslands, which is owned and operated by The Nature Conservancy, is located on Lowden Rd.