From the excellent Bad Postcards blog:
WORLD’S LARGEST JACK RABBIT
Verso: “True Plains Rabbit lives only in the West. Burro-like ears gave him his name. Color is protective, blending with sand and dry grass. Very long legs made him a swift runner. Clocked at speeds to 45 miles an hour. Object of hunts with Greyhounds. The rabbit was prized by Plains Indians for food and fur, to the white man a reminder of Desert-Hard Life. In Drought and Depression times, it was a source of meat for thousands, Subject of many tall tales. Hero of World’s only Jackrabbit rodeo in Odessa, May 1932.”
The postcard is from 1967.