Historic Alcatraz Island -
Somewhere between seven and ten thousand years ago, the world's most recent Ice Age ended - and the seas rose to the levels we see today. Two great river canyons, separated by a small mountain, made their way to the Pacific Ocean - bringing with them great volumes of water from the Sierra mountain range - three hundred miles to the east.
When the rising seas encroached inland some twenty miles, these two sister canyons were flooded - and the mountain between them became an island. American Indians' spoken histories tell of this mountain as a rich hunting ground - and later of a nearly barren island they could only reach in hand-crafted tule-reed canoes - presumably to gather eggs from the abundant nesting seabird colonies.
These first explorers of a place we now know as Alcatraz Island would have been the men, and young men, of the local Ohlone and Miwok tribes who lived along the shores of the surrounding estuary waters. The seabirds are still here.