Bison at Jester Park
The bison (or buffalo) is the largest hooved mammal in North America. It is estimated that when the Europeans arrived in America, there were 50-75 million bison on the continent. Bison were found throughout Iowa, with the largest concentrations in the northwestern and north-central parts of the state.
In the late 1890s, the numbers of bison across the continent dropped as low as 1000 due to overhunting. The last wild bison seen in Polk County was in 1850 and completely disappeared from Iowa in 1870.
Today, they have gradually made a comeback and are numbered at more than 40,000 in North America. There are no wild bison living in Iowa. Although, several small captive herds exist today throughout the state. One of these herds can be seen at the Jester Park wildlife enclosure which is accessible year round.
Enature.com - This page provides a complete online field guide for bison as well as other groups of animals.