Cattle can gain up to two pounds per day grazing on the prairie grasses of the Flint Hills. The calcium found in the limestone erodes into the soil, making the prairie plants more nutritious for grazing animals. Because Bluestem grasses have root systems which extend more than 8’ underground, they are extremely drought–resistant and actually flourish with the annual spring burn-off of pasture. This deliberate burning of old grass was practiced by American Indians, but the American agricultural practice discontinued controlled pasture burning by the late 19th century onward save for the Flint Hills region. It was not until the late 20th century, that range management and scientific experiments proved that regularly burned pastures had healthier grass with fewer weeds and woody plants and produced better livestock gains than did unburned grass. Had it not been for the folk culture of the Flint Hills, this economically-efficient and environmentally-sustainable farming method might have been lost. What is also unique about the Flint Hills is that the Bluestem grasses are so resilient with the ability to store their own nutrients, that they actually thrive with grazing, unlike other fragile ecosystems elsewhere in the world.