Lake Pepin occupies a valley carved by the waters of Glacial River Warren, which drained Lake Agassiz in a catastrophic flood at the end of the last Ice Age, and to a lesser extent from Lake Duluth, a smaller glacial lake which drained through the present valley of the St. Croix River. When the continental glacier’s meltwaters found other outlets to the sea, River Warren was succeeded by the more modest Upper Mississippi, which drains a much smaller basin, and the St. Croix spillway became the present river. Over a long period of time, the deep valley was partially filled with sediments, forming a broad floodplain. In this plain Lake Pepin formed behind a delta comprising sediments deposited into the ancient lake bed by the Chippewa River near the present community of Wabasha at the southern end of the lake. The lake backed up behind this sediment dam as far north as the location of Saint Paul. In the 10,000 years since the lake’s creation, ongoing sedimentation into Lake Pepin has caused its upper end to migrate downstream some 50 miles to its present location east (river direction south) of Red Wing, Minnesota. ~wikipedia
![ake Pepin occupies a valley carved by the waters of Glacial River Warren, which drained Lake Agassiz in a catastrophic flood at the end of the last Ice Age, and to a lesser extent from Lake Duluth, a smaller glacial lake which drained through the present valley of the St. Croix River. When the continental glacier's meltwaters found other outlets to the sea, River Warren was succeeded by the more modest Upper Mississippi, which drains a much smaller basin, and the St. Croix spillway became the present river. Over a long period of time, the deep valley was partially filled with sediments, forming a broad floodplain. In this plain Lake Pepin formed behind a delta comprising sediments deposited into the ancient lake bed by the Chippewa River near the present community of Wabasha at the southern end of the lake. The lake backed up behind this sediment dam as far north as the location of Saint Paul. In the 10,000 years since the lake's creation, ongoing sedimentation into Lake Pepin has caused its upper end to migrate downstream some 80km (50mi) to its present location east (river direction south) of Red Wing, Minnesota.[5]](https://i0.wp.com/traun-photo.com/dan/wp-content/uploads/2019/09/2019-09-19-DF068-Around-the-Lake-0001-7-Edit-2.jpg)
