But, in fact, there is no exact date for the passing of the frontier.

Its decline set in on what day the first lank "nester" from the States outspanned his sun-burned team as he pulled up beside some sweet water on the rolling lands, somewhere in the West, and looked about him, and looked again at the land map held in his hand.
"I reckon this is our land, Mother," said he.
When he said that, he pronounced the doom of the old frontier..