When the glaciers receded about 10,000 years ago, they left behind moraines, drumlins, and recession of the glaciers is so recent (in geologic terms) that modern-day drainage patterns are immature and poorly established.
They left behind moraines. This was drumlins. The glaciers receded about 10,000 years ago. Modern-day drainage patterns are immature and poorly established. Recession of the glaciers is so recent (in geologic terms) this.