The dynamic structure of wheat acreage supply response is considerably more complex than previous studies have recognized. The distributed lag response is saw-toothed in its pattern, which is believed to eminate from the influence of summer fallow in crop rotations in the Great Plains. The acreage response elasticity estimate for the Great Plains at mean price was 1.3, and for the aggregate U.S. it was 1.5. For the Unites States, the proportion of long-run response experienced over the first five years from an increment to price was .24, .44, .70, .95, and. 99.