Location: Glen Canyon National Recreation Area (Lake Powell). There are countless narrow canyons having still water such as this. Depending on the specific location - as Lake powell is said to have approximately 2,000 miles of shoreline - this formation is either the Cedar Mesa formation of Permian age, or the Navajo Sandstone of Jurassic age. The northern end of Lake powell has a greater exposure of the former, whilst the mid-to-southern end has greater amounts of Navajo Sandstone.