The Golden Gate strait is a gap in a mountain rang...

The Golden Gate strait is a gap in a mountain range that was cut by an ancient river that passed through what was a dry valley until 10,000 years ago. That was when sea level was over 100 meters lower than today. The melting ice caused by the end of the last ice age raised the level of the sea, and the ocean slowly flowed back up the river canyon to form San Francisco Bay. Today, 60% of the rain and snow that falls on the State of California still drains through the Golden Gate.