This photo by the famed photographer Asahel Curtis caught a man fishing along a river circa 1920, likely in the Green River G

By Bill Kombol

This photo by the famed photographer Asahel Curtis caught a man fishing along a river circa 1920, likely in the Green River Gorge below the mining town of Franklin. In this area the Green River flows through a 40-50 million year-old bedrock formation known as the Puget Group, measured over 6,000 feet stratigraphically. During the Eocene age, King County was a tropical climate and the site of a large estuary, as Magnolias, figs, palms, and tree ferns grew in the many surrounding swamps. The swamps filled and the rich carbon matter was covered by the eroding sandstones and shales from surrounding hills. In time the vegetative matter compressed into coal beds. There are over 30 coal seams in the Kummer and Franklin series of the Puget formation, named after two mining towns which operated along the Green River. The coal seams are in turn separated by massive layers of sedimentary rock comprised of sandstone, siltstone, and claystone, often interbedded with carbonaceous matter, which make up the 6,200 foot thick geologic strata. Each layer in turn represents many changing climates and sea levels during those geologic time periods. One can actually see exposed coal seams as you walk along the steep canyon walls or float down the dangerous waters of the Gorge. The last great change which formed the Green River Gorge we know today, were the glaciers which covered this area until 10-14,000 years ago. As glaciers melted the rushing waters cut the deep canyon topography which still causes visitors to marvel. This Asahel Curtis photo number 60713 comes courtesy of the Washington State Digital Archives, item number AR-280010001-ph002054.