Withrow Moraine and Jameson Lake Drumlin Field erosion resulting from the Missoula Floods, which laid bare many layers of the basalt flows on the edges of the plateau at Grand Coulee and Moses Coulee. Two million years ago the Pleistocene epoch began and Ice age glaciers invaded the area. They scoured the Columbia River Plateau, reaching as far south as the middle of the Waterville Plateau highlands above the Grand Coulee and south to the head of Moses Coulee. In some areas north of the Grand Coulee they were as much as 3 km (10000 feet) thick. Grooves in the exposed granite bedrock are still visible in
Birch Coulee Battlefield soldier Albert Colgrave. Guideposts mark the U.S. camp and the positions of the surrounding Dakota. Management has since been transferred to the Renville County Parks Department, which also maintains a campground on site. Birch Coulee Battlefield Birch Coulee Battlefield in Renville County, Minnesota, United States, was the site of the Battle of Birch Coulee, the costliest military engagement for U.S. forces during the Dakota War of 1862. It is now a historic site with self-guided trails and markers interpreting the battle from both sides. Birch Coulee was nominated to the National Register of Historic Places for having state-level significance in