The animal that kills the most people in the U.S. is male Buffalo

The reason for this is that they are herd animals. There is nowhere really for them to run because there often are so many of them. So, the male buffalo if they feel they or their herd is threatened will kill people. It's similar to the way Rhinos kill people. First they knock them down off their feet and then they use their front hooves to smash flat the people's heads or chests. So, someone can be literally killed by a buffalo (or Rhino) in seconds. One, you are up looking at a buffalo then then two you are knocked down and a second later your head or chest is crushed. This is what happens within about 2 seconds when someone dies from a male buffalo in places like Yellowstone National Park or Teton National Park. 

So, you either need to give male buffaloes or cows with babies a whole lot of room or you could be a death statistic too when you see them. They won't run away if they are males or cows with babies they will just turn and knock you down.