And the dove came in to him in the evening; and, lo, in her mouth was an olive leaf pluckt off: so Noah knew that the waters were abated from off the earth.
Genesis 8:11
"In the 1830s, George Catlin stood in amazement as he was to
watch the annual ceremony of the Mandan tribe of North Dakota. 
This
ceremony, which the Mandan have solemnly observed since ancient times,
vividly preserved the memory of Nu-mohkmunk-a-nah, “the only man,” the
Noah of the Mandan tribe.
This man, they told, survived the flood and
landed his big canoe on a mountain far to the west. This elaborate
ritual demonstrated a memory of the flood very similar to the Genesis
account even to several details.
For example, Catlin described the “bull
dance,” which was performed 40 times during this ceremony, “the exact
number of days that it rained upon the earth, according to the Mosaic
account.” The Mandans also highly esteemed the turtle dove, which they
say returned to their Noah carrying a willow bough in its mouth as a
sign of the retreating waters." AIG
