Traverse Gap

The Laurentide Ice Sheet decayed and receded as the Wisconsonian glaciation drew to a close, and Glacial Lake Agassiz formed from its meltwaters.

The resulting enormous outflow of the lake carved a deep spillway through the moraine, through which cascaded Glacial River Warren.

[3] With its former source now draining elsewhere, River Warren ceased to flow, and the spillway gorge became the Traverse Gap, now occupied by much smaller lakes and watercourses and a flat valley floor containing marshes, agricultural land, and the small community of Browns Valley, Minnesota.

[5] Despite the low elevation and flat topography of its floor, the Traverse Gap marks the southernmost point of the Northern Divide between the watersheds of the Arctic and the Atlantic Oceans.

The Little Minnesota, part of the Mississippi watershed, is less than one mile (1.6 km) from Lake Traverse in the drainage basin of Hudson Bay.

[7] While the natural state of the area has been altered by the dike and control structures on the two lakes, interbasin flooding did occur prior to construction of those improvements.

[7] The ancient channel at Browns Valley is a mile (1.6 km) wide and some 130 feet (40 m) deeper than the surrounding terrain through which it was carved.

A Paleo-Indian skeleton now known as "Browns Valley Man" was unearthed in 1933 under circumstances which suggested death or interment after deposition of the gravel but before creation of significant topsoil.

[4][10] The Traverse Gap was used by Native Americans, who "from time immemorial ... had placed two weather-beaten buffalo skulls where travelers paused to smoke a pipe at the divide.

In fact, both these bodies of water are in the same valley; and it is within the recollection of some persons, now in the country, that a boat once floated from Lake Travers into the St. Peter.

Traverse Gap looking south from ice-covered Lake Traverse (bottom of frame) to Big Stone Lake (top). Interbasin flooding is shown: The Little Minnesota River in the Mississippi watershed is entering from the west (meanders at center right margin) and is flooding the Traverse Gap (gray water, surrounding the town of Browns Valley in the center). At lower right, floodwaters from the Little Minnesota are crossing the continental divide and flowing under South Dakota Highway 10 into Lake Traverse in the watershed of Hudson Bay .
1895 map of the region of southern Lake Agassiz , showing how the lake (its bed shown in green) funneled into the Traverse Gap at Lake Traverse . The squares are civil townships and sections within those townships under the Public Land Survey System used to subdivide public lands for sale. Minnesota is to the east (right) of the watercourses; North Dakota to the north and west (upper left) and South Dakota to the south and west.