The 1907 High Relief $20 Gold Piece was designed by the noted American sculptor Augustus Saint-Gaudens at the request of President Theodore Roosevelt. "High Relief" refers to the depth of the details which, on this coin, are much deeper than usual, giving the coin an impressive medallic appearance. "High Reliefs" come in several varieties: the extremely rare Ultra-High Relief and the more common Flat Rim and Knife (or Wire) Rim variants. Saint-Gaudens' obverse design was considered so beautiful and so popular that it was re-used on the gold bullion coins struck by the U.S. Mint beginning in 1986.
The Wire Edge on some of the regular-issue High Reliefs is more of a striking anomaly than an actual variety, although they are collected as such. During the striking process, extreme pressure forces the metal of the planchet into all the recessed areas of the dies. If the diameter of the edge collar exceeds the diameter of the die, a wire edge will encircle the coin. If the die is misaligned relative to the edge collar in any direction, a wire edge will be created wherever there is a separation between the die and the edge collar.
The High Relief version of the Saint Gaudens $20 proved impractical for mass production and a lower relief version with Arabic numerals in the date was produced later in 1907.