Which mammal runs the fastest?

chetah is the fastest land animal
   The cheetah (Acinonyx jubatus) is the fastest land mammal. When chasing prey, an adult can accelerate to 70 miles per hour, but it can maintain this speed for only 300 yards. The flexible spine acts like a spring for the powerful hind legs, and the claws provide traction. A mature chee­tah weighs up to 130 pounds and averages 6 feet in length, including the 30-inch tail, which maintains balance during quick turns.
   With fewer than 15,000 in the wild, the cheetah is an endangered species. The cats were first killed for their pelts; now encroaching civilization is severely limiting their range and food supply. Cheetahs live on the grassy plains of eastern and southern Africa, Iran, Turkmenistan, and Afghanistan.
   The antelope (Antilocapra americana) is the champion long-distance runner, maintaining up to 35 miles per hour for 4 miles when pursued.