Very small streams dripping into very small pools. Which run into larger streams. Which run into lakes. And then into rivers. Back into lakes. More rivers. Then into Hudson Bay. 

(A partially complete list of how this drop may make it into the ocean is: Kabetogama Lake, Rainy Lake, Rainy River, Lake of the Woods, Winnipeg River, Lake Winnipeg, Nelson River, and Hudson Bay. Fun fact: by an odd coincidence the distance this drop might travel is almost exactly the same as the distance a drop that falls 130 miles away into Lake Itasca might take down the length of the Mississippi River.)