also the product of a much longer story, one that can be started with the breakup of the Pangaea super-continent. As the continents began to spread out, the North American Plate inched westward, grinding over and against the Pacific Plate as it went. This subduction of the Pacific Plate caused the rise of the Rocky Mountains and thereby the Missions. About 66 million years ago, this process of uplift began to slow. This time, called the Cenozoic Era, is when the area began to look much like it does today. Looking at the globe at that time, the continents would have been about where they are today and plant and animal life would be recognizable. At that time, however, the deep valleys of western Montana would not yet have formed. This development is believed to have come about 40 million years ago as the extensional forces that caused the uplift of the Rockies began to cause the crust to thin and crack. Near-vertical faults formed almost uniformly throughout the region, most trending northwest to southeast. The blocks then broke up, some dropping and creating valleys like the Flathead and the Swan. In all, the whole process took around 100 million years. Pleistocene glaciation Three million years ago, at the end of the Cenozoic Era, western Montana would have been full of tall mountains, but it was the next geologic process that made them what they are today. Large glaciers began to form in the area 2–3 million years ago; this was the beginning of the Pleistocene Epoch. Since then, ending just 10,000 years ago, the Mission Mountains and their surroundings have been shaped by water. The formation of the Flathead Lobe of the Alberta Cordilleran ice sheet is what set this history into motion. At its thickest points, the Flathead Lobe glacier may have extended 4,000 feet above the valley floor. The glacier reached hundreds of miles down the Rocky Mountain Trench, ending as far south as St. Ignatius, Montana. At the northern end of the range, the glacier flow split, in part flowing slowly into the Swan Valley. A view of the area at that time would have been majestic, with large glaciers flowing around both sides and partially over the range. Smaller glaciers would have also flowed out of the mountains and joined the larger one in the valley. This explains the southward pointed, hook-shaped ridges at the