What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
The 2004 D Wisconsin State Quarter had a major variety/error in which an extra leaf was added just to the bottom-left side of the corn cob. Typically there is no extra leaf in this location. There are two varieties of this type in which the leave extends higher or sits lower. In the variety depicted above - the leaf is higher up as depicted by the arrow in the example image. The difference between the low leaf vs high leaf is depicted below in the example comparison image of the coins:
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD