 Rainfall decreases from east to west, resulting in different types of prairies, with the tallgrass prairie in the wetter eastern region, mixed-grass prairie in the central Great Plains, and shortgrass prairie towards the rain shadow of the Rockies.Today, these three prairie types largely correspond to the corn/soybean area, the wheat belt, and the western rangelands, respectively.Much of the coniferous forests of the Upper Midwest were clear-cut in the late 19th century, and mixed hardwood forests have become a major component of the new woodlands since then.