A second shot from this impressive location. Jenny Lake is located in Grand Teton National Park in the U.S. state of Wyoming. The lake was formed approximately 12,000 years ago by glaciers pushing rock debris which carved Cascade Canyon during the last glacial maximum, forming a terminal moraine which now impounds the lake. The lake is estimated to be 423 feet (129 m) deep and encompasses 1,191 acres (482 ha). Jenny Lake is considered to be a major focal point in Grand Teton National Park, with many hiking trails, scenic boat rides and a quick access to the major climbing routes into the tallest peaks of the Teton Range.