By Roger Cornish, KWCH 12 Eyewitness News

The U.S. Fish and Wildlife Service has concluded that a petition to list the wild plains bison under the Endangered Species Act does not contain substantial scientific data to indicate that the petitioned action might be warranted.

The Service made this determination in response to a petition received on June 22, 2009 from James and Natalie Bailey to list the wild plains bison as a threatened species.

Under the ESA, the Service is required to review the petition to decide whether it contained substantial scientific information that listing may be warranted in a process known as a 90-day finding.

Bison are the largest native terrestrial mammal in North America.

Historically, plains bison numbered in the tens of millions and were found nearly coast to coast from central Canada to northern Mexico. They were eliminated west of the Rocky Mountains and east of the Mississippi River by the early 1800s.

By 1889, only a few wild plains bison remained in the Texas Panhandle, Colorado, Wyoming, Montana, and the western Dakotas, as well as a small number in captive herds.

Today, there are over 400,000 plains bison, with approximately 20,500 managed in conservation herds in parks, preserves, other public lands, and on private lands throughout and external to their historical range.

Population trends have been stable to increasing in recent years.