Native Americans from the U.S. and Canada plan to cross the Detroit River between Michigan and Ontario in a flotilla of canoes that could halt shipping.

The Detroit Free Press reports Thursday that organizers seek to launch as many as 200 canoes Aug. 27 from the Detroit island park of Belle Isle to Windsor, Ontario, and back. The three-hour event -- designed as a celebration of culture -- comes the day before a two-day powwow scheduled in the Detroit suburb of Lincoln Park.

American Indian Movement of Michigan Chairman Bryan Halfday says a 1796 treaty allows for such crossings by native people of the U.S. and Canada.

U.S. Coast Guard spokeswoman Lauren Jorgensen says she's unaware of the planned event but would look into it.