American bison

American bison (Bison bison)
Image attribution: Jack Dykinga / Public domain. Image source.

Prior to the 1800s, American bison (Bison bison) likely numbered in the tens of millions. Large herds roamed across much of Canada, the United States, and northern Mexico. During the 1800s, colonization of western America was accompanied by mass slaughter and exploitation of bison. By 1900, only a few hundred individuals remained and in small, isolated populations. Today, conservation efforts have restored bison herds at several locations in Canada, the United States and, more recently, Mexico. However, the vast majority of bison currently in the U.S. are members of captive herds maintained for commercial purposes.

Bison rage prior to 1720 (tan area), bison range as of 1870 (light brown area), and bison range as of 1889 (dark brown regions). Year of localized exterminations are indicated (light numbers), as well as population estimates for disjunct populations during 1889 (dark numbers).

Image attribution: Cephas / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). Image source.

Locations of herds of plains bison (Bison bison bison, dark brown circles) and wood bison (Bison bison athabascae, tan rhombus) as of 2003. For a list of the named places indicated by this map, click here.

Image attribution: Cephas / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0). Image source.

For information on American bison conservation efforts:
American Prairie Reserve - Bison Restoration
National Park Service - Protecting Bison
Wildlife Conservation Society - The Future of Bison
World Wildlife Fund - Bison Facts
IUCN Red List - American Bison