In Colorado’s “most remote” mountain town, there’s no doubt the Earth is constantly moving.
A rarely seen natural event is occurring near Lake City, the only incorporated municipality of Hinsdale County, called an earthflow. At a rate as high as 20 feet per year, the earthflow has since changed the landscape and created Colorado’s second-largest natural lake.
The Slumgullion Earthflow began about 700 years ago as heavy rains weakened volcanic tuff and breccia on the southern flank of Mesa Seco. The slow-motion landslide was so massive and cataclysmic that it created a natural dam and blocked the Lake Fork of the Gunnison River, ultimately forming Lake San Cristobal.
Today’s active earthflow, which is a portion of the larger Slumgullion Earthflow, began about 350 years ago and continues to move at a rate as high as 20 feet per year, separating and scattering pine trees on the hillside.
Slumgullion is considered a good natural laboratory allowing geologists and other scientists to experiment and gather data on landslides since the late 1800s. By the 1990s, scientists of the United States Geological Survey began mapping every fault, fold, crack, and crevice of the earthflow and documented aerial photographs. Studies show today’s earthflow moves at higher rates during late spring and summer season when more water saturates the ground. The rate of the earthflow is also relative to the moon’s tidal forces and air pressure. Scientists today state the earthflow is likely slowing and will eventually stop. The slower rates could be caused by decreased rainfall and increased temperatures recorded in Colorado between 1895 to 2010.
The earthflow can be seen along Colorado Highway 149 – Silver Thread Scenic Byway – between Creede and Lake City. The Windy Point Overlook along CO-149 offers great views of the slide and of the San Juan Mountains that surround Lake City. Those with a 4x4 vehicle can drive up Mesa Seco at an elevation of 12,618 feet above sea level to see up-close views of the earthflow in Colorado’s San Juan Mountains.
This area is also known to be the site of where Colorado’s notorious cannibal became stranded with a hunting group in winter of 1873-1874. During the expedition, a blizzard moved in and left the men stranded. It was determined that Alferd Packer killed the members of his group, claiming it was an act of self defense and necessary for survival. At trial in 1883, Packer admitted to leaving the remains of his hunting group near a big landslide of yellowish clay, which ultimately described the geology of the Slumgullion Earthflow.
Today, people are able to hike to the site where the Colorado Cannibal event are said to have taken place.