Porte des Morts

At its narrowest reach between Plum Island and the peninsula, the Porte des Morts Passage is about one and one third miles across.

[2] According to traditions given by the Native Americans to area fishermen in the 1840s and reported both by Captain Brink, a government engineer who surveyed the area in 1834, and by Hjalmar R. Holand in his two-volume history of Door County,[3] the ominous name is traced back to a battle between the Winnebago and Potawatomi tribes.

Various historical accounts indicate that it was the Potawatomi who were the newcomers to the area and that the Winnebago had recently suffered greatly at the hands of the Illinois.

One account involving Native Americans has a tribe building a ring of campfires on thin ice to lure their enemies through the strait overnight.

It has also been said that the French, not wanting the English to establish fur trade routes to Wisconsin and other surrounding areas, named the passage to discourage and scare sailors from sailing through the strait.

The written history of the area between Jean Nicolet's visit to Green Bay in 1634 and the return of French trappers in the late 1650s is virtually a blank page.

R. David Edmunds relates that after the Winnebago successfully repulsed the first advance of the Potawatomi, they lost several hundred warriors in a storm on Lake Michigan.

[7] Carol Mason also refers to the loss of 600 warriors, but does not indicate on which body of water they were lost and questions the credibility of the report.

[8] Lee Sultzman says Lake Winnebago was the location and that 500 warriors were lost in a failed attack against the Fox.

[12] Finally, it appears that a sizeable contingent of their historic enemies, the Illinois, came on a mission of mercy to help the Winnebago at time of suffering and famine—what one might expect after the loss of 600 men who were also their hunters.

While it must remain speculation, it is nonetheless reasonable to conclude that the Porte des Morts battle really happened, that it was the end of the Winnebago's pushing out the first wave of Potawatomi, that the loss of 600 warriors in a storm corresponds with the loss of warriors in the Porte des Morts tradition, and that the event marked not just the doorway to death for those who died at the bluff and in the storm, but the beginning of events that brought death to nearly the whole tribe.

The most recent "discovery" is awaiting funding and legal process before it can collect sufficient evidence to support or refute the claim.

[14] Another ship erroneously said to have grounded in Death's Door is the Louisiana, which records clearly show beached and burned on the shore of Washington Harbor [15][16] Death's Door was used primarily by vessels sailing between ports along Green Bay and those along middle to southern Lake Michigan.

[17] In 1978 it was reported that waves in the Porte des Morts passage can exceed those in Green Bay or Lake Michigan by up to 0.6 meters (two feet).

[19] Water conditions begin to deteriorate in August and are worst in October and November, when lakewide wave heights of 5 to 10 feet are encountered about 35 percent of the time.

Along the Lake Michigan shore, spring winds are variable, particularly in the morning, when northerlies, easterlies, and southerlies are among the most common.

However, Green Bay recorded a 95-knot southwesterly one May; it is not unrealistic to expect a wind extreme of 100 knots or more over open waters.

Detail of NOAA Chart #14909
Closer detail of NOAA Chart
If the Porte des Morts battle happened it could have occurred here at Door Bluff (also called Deathdoor Bluff). This is typical of a number of places on the northern coast of the Door Peninsula. The escarpment seen here is between 15 and 20 feet high. Above that is a gentle slope up for about 50 feet and another similar escarpment above that. The broad flat rocks at the base of the cliff are high enough to be out of most of the surf in stormy seas, yet low enough to be awash in a rogue wave. At the time this photo was taken, the lake was about 1.8 feet below its long term average level. The wind was from the south at about 15 mph, gusting to about 25 mph. In the "Detail of NOAA Chart #14909" (above), Deathdoor Bluff is the point at the far left of the chart.
"A small ledge just above the water at Door Bluff County Park, measuring about 6 feet by 18 feet."
A couple observing a wreck in the Porte des Morts; from a postcard prior to 1915
Porte des Morts Passage from beach at Northport, showing ferry harbor breakwater and Plum Island at left, Detroit Island center, and Pilot Island at right. An abandoned lighthouse is the only structure on Pilot Island.
Ice stringers, February 22, 2014. On that day, southwesterly winds were blowing ice into the lake in the form of long, coherent stringers. The thickness of a stringer is related to the length of coastline that feeds it. The smallest northern stringer (image left) is fed by the shortest section of upwind coastline, and the longest (image right) is supplied by the large amount of shore ice around Detroit Island.