Berlin the polar bear plays with a ball on her eighteenth birthday, 2007

Bessie the elephant, Lake Superior Zoo, 1974.

A rhinoceros at the Lake Superior Zoo, 1964.

Lloyd Hackl with Mr. Magoo the mongoose, 1963.

The bear den at the Duluth Zoo, ca. 1940.

Bird’s eye view of the Duluth Zoo, ca. 1940.

Elephant House at the Duluth Zoo, ca. 1940.

Chimpanzee House, Duluth Zoo, ca. 1936.

Billy the deer at four years old, Lake Superior Zoo, ca. 1927.

Bert Onsgard with Billy the deer, Lake Superior Zoo, 1923.