They contain evidence of present and past glacial activity.

During the Pleistocene the state was subjected to glacial activity.

The lake was formed from glacial activity in the Pleistocene.

Scientists working in the park and preserve hope to learn how glacial activity relates to climate change.

The crater was eventually filled by glacial activity, so that no trace now remains on the surface.

The area was formed thousands of years ago by glacial activity.

The hills were created by glacial activity in the last Ice Age.

Signs of the glacial activity are still visible today.

The dinosaur bones reworked by glacial activity are the best in the state.

At that time the state's entire landscape was reworked by glacial activity.