Before The Indians had horses ,they used to stampede buffalo over cliffs,I should think this is not only indiscriminate ,and wasteful ,but unreconcilable with your statement.  
 
What do you mean before they had horses? They existed over there long before the white man arrived so I doubt they would have ever been without horses. It wouldn't have been recorded either just word of mouth which wouldn't have lasted long, are you sure? honestly want to know where you got this  
 
  
Horses were introduced into the Americas by white men from the 15th century onwards AKA "The Spaniards" their horse