The west coast of North America once extended 27 miles west of the Golden Gate. The San Francisco Bay as we know it is a very young landform in geologic time. View this segment to learn

• how the west coast of North America has changed dramatically over time.
• when the Bay with which we are familiar was created.
• how San Francisco Bay is a flooded river canyon that formed as a result of rising sea levels at the end of the last ice age.

Download the Viewing Guide for pre- and post-viewing discussion questions, activities, and additional resources to use with students.

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