The Efroymson Restoration at Kankakee Sands is 8,400 acres (3,400 ha) of prairies and wetlands connecting Willow Slough Fish and Wildlife Area, Beaver Lake Nature Preserve, Conrad Savanna Nature Preserve and Conrad Station Savanna.

About 14,000 to 16,000 years ago, sands were deposited from glacial melt waters flowing from the retreating Laurentide ice sheet during the Wisconsin glaciation.

[3] This area is part of the Grand Kankakee Marsh system and the site of the largest natural lake in Indiana until it was drained.

[7] They prefer grasses and sedges, leaving the flowering plants, which support a range of insects and animals.

[9] The conservancy maintains a dozen herds through North and South Dakota, Nebraska, Iowa, Illinois, Colorado, Kansas, Missouri, and Oklahoma.