the corn palace in mitchell, south dakota. palace director mark shelling. >> the corn palace attracts a half a million people per year. this is the biggest monument to corn that we have in the entire world. >> not only is the biggest, it's also the onliest. people drive from presumably elsewhere to see the murr alls made of 12 different colors of corn. >> since 1892 we have been redecorating the corn palace with a new theme each year. people really cannot believe that the murr alls are made out of corn until they experience it and see it for themselves. and they start saying, that is an ear of corn, wow, this is truly amazing. >> but a drought in the heartland has threatened this annual tradition. the world's only corn palace has brought in tourists to mitchell for a number of decades. the drought this year may take its toll on the corn used to make those murr alls. >> because of the drought, four of the colors that we would typically use in our murr all designs are not going to be available for us this year. >> we've seen the