This area is known as the Coulee Region for its absence of glacial drift.
While some glacial drift has been discovered, this is said to be of Pre-Illinoian age, about 500,000 years old.
The remnants of these valleys were buried by glacial drift.
The river was named for yellowish glacial drift in bluffs along the river.
This area is known as the Driftless Zone for its absence of glacial drift.
The valley floor is mainly covered by glacial drift.
The result is one of the world's largest pockets of land entirely surrounded by glacial drift.
The glacial drift has cobbles that are well polished by the wind and cut into ventifacts.
They consist of glacial drift, with till being the most common constituent.
Only in my leisure time I intend to take up the study of the ice ages and the glacial drift.