Bridges are some of the most majestic features in the American landscape. For classrooms, the bridge serves as an important component of one of the main themes of geography: movement. One bridge, north of Manhattan and crossing the Hudson River, is the Tappan Zee. One aspect that stands out in a way that does not at all appear reasonable: the bridge is situated at one of the widest points of the Hudson River. The authors believe that unraveling the "why there" of the Tappan Zee Bridge is useful for understanding the interplay between physical and political geography, and for providing students with the opportunity to use geospatial technology. The lesson described here explains the Tappan Zee case by using Google Earth and an online geographic information system (GIS) to uncover plausible siting motives. In the end, when the real siting decision is revealed, students realize that the reasonableness of a bridge's location is also related to the context of its time. (Contains 4 figures, 3 online resources, and 7 notes.)