The 550-meter-thick upper Cambrian (Furongian Epoch) Notch Peak Formation of western Utah has over a dozen horizons of meter- to multiple-meter-thick sequences of stromatolites that have been correlated with similar stromatolitic beds in the Drum Mountains to the north and the Wah Wah mountains to the south, providing a total geographic distribution greater than 2,600 square kilometres. Cambrian stromatolitic beds have also been described from other areas in North America that circumscribe what appears to be the ancient coast of the North American craton associated with Laurentia. A total of 24 different locations span North America starting in Newfoundland, traveling down to the New York area, crossing the southern United States to Texas, then moving over to the region around Utah, California, and Nevada, before continuing the trail northward through Idaho, Alberta and on into the Northwest Territories of Canada. These growth structures challenge the majority creationist consensus that places the onset of the Flood at, or near, the Proterozoic/Paleozoic boundary. For this latter position to be valid, thick, and geographically widespread sequences of stromatolites would necessarily have had to have grown during the initial stages of the Flood (in just months), when, according to many creationists upwards of 1000 meters of continental crust was being eroded from the craton at almost the same time. For this reason, I propose that processes related to the erosion of the craton and associated with the Great Unconformity be placed within Creation Week, thus removing its place as a primary marker for the onset of the Flood.