The story of the novel takes place 80,000 years ago, during the last glacial period.

The last glacial period of the current ice age ended about 10,000 years ago.

The boulder field was created about 20,000 years ago during the most recent glacial period.

There were six of those glacial periods, with two million years or so between each.

The basin then filled with water at the end of the glacial period.

Although the last glacial period ended more than 8,000 years ago, its effects can still be felt today.

The first human settlement of is thought to have happened between 30,000 and 14,000 years ago during the last glacial period.

They are important in determining sea level rise since the last glacial period.

At the end of the glacial period there was an ice front here.

The river began flowing along its present course after the end of the last glacial period.