US Fish & Wildlife Service
Date of this Version
It is believed that buffalo, or bison, crossed over a land bridge that once connected the Asian and North American continents. Through the centuries buffalo slowly moved southward, eventually reaching as far south as Mexico and as far east as the Atlantic Coast, extending south to Florida. But the largest herds were found on the plains and prairies from the Rocky Mountains east to the Mississippi River, and from Great Slave Lake in Canada to Texas.
Because the great herds were nearly gone before any organized attempts were made to survey populations, we may never know just how many buffalo once roamed North Amercia, although estimates range from 30 to 75 million. "The moving multitude...darkened the whole plains," wrote Lewis and Clark, who encountered a herd at South Dakota's White River in 1806.
Published by the U.S. Fish and Wildlife Service, 1-2, (1997)