South East Alaska, also known as the Alexander Archipelago, is home to numerous caves and karst features. On El Capitan Peak, Prince of Wales Island, you can find El Cap pit, the deepest single drop limestone pit in the States at 600 feet. The Tongass Cave Project (TCP), a project of the National Speleological Society, has surveyed and mapped more than 500 caves, with plenty more still to be discovered. These caves are home to many beautiful formations, some unique to this area. Getting around SE is difficult at best- the terrain is steep, cliffy and heavily wooded in this temperate rainforest with 150 to 200 inches per year. Many of the islands don’t have daily ferry service, if any at all. Then there’s the wildlife. During summer you’ll find salmon in all the streams. This is where the bears hang out, chowing down, putting on fat for winter hibernation. Wolves are on most of the islands, being elusive, but you gotta wonder, when people go missing.
During the summer months the Forest Service gives free tours of El Capitan cave (not El Cap pit). Even though this is the longest cave in Alaska at 12,600 feet of surveyed passage, the tours only visit a small portion of the main passage. If you want to explore on your own, try Beaver Falls cave, or strike out on your own if you feel adventurous and discover one not yet known. Other caves such as On Your Knees Cave have turned up evidence of the earliest known human activity on the North Pacific coast at 10,500 years before present. And others with animal remains dated at 42,000 years before present have rewritten previous theories on the extent of glacial ice coverage during various ice ages.
Karst is defined as a landform characterized by subsurface drainage, commonly found on carbonate soils, such as limestone and marble. There are over 850 square miles of karstlands in SE. Thru the action of plate tectonics the limestone drifted up from the equatorial regions where it was active coral reef during the Silurian Age 400 million years ago. The areas of marble metamorphosed when heat and pressure were applied to the limestone due to intrusive igneous materials. The caves are formed when the abundant waters acidify due to tannic acid from plants and carbonic acid from the moist air react with the alkaline limestone rock creating a process of dis-solution. As the water percolates down through the cracks and fissures the rock ‘dissolves’ and caves are formed. Due to the well drained soils and available nutrients on the karst the biggest and best old growth trees are found here, with many over 500 years old. While 80 percent of the karst has been clearcut logged already there are a few isolated spots of big timber left.
TCP has worked tirelessly since 1991 to curb the Forest Service’s plans to log the Tongass National Forest. They have worked with many environmental organizations such as Greenpeace, Earth Justice, Environmental Defense Fund, Southeast Conservation Council (to name just a few) in the effort to protect this National Treasure. TCP has had invaluable help with volunteers from around the world walking the forest, finding and mapping these features and then using such tools as the Federal Cave Resources Protection Act, the Clean Water Act, and the Standards and Guidelines of the Forest Service to curtail logging and road building activities on the karst. Their volunteer work has taken thousands of acres of high value karstlands out of the timber pool and off the chopping block. Many caves have been saved from being negatively impacted by logging activities.