The Montezuma Well sinkhole has developed a unique oasis environment in the Northern Arizona desert.
Montezuma Well formed when water percolating through the Mogollon Rim limestone (a 10,000 year trip) encountered a hard basalt ridge that forces it back towards the surface. A cavern formed that eventually collapsed to form the current sink hole. The water continues to flow into the sinkhole at a rate of 1.5 million gallons (57.6 million liters) per day and overflows through a cavern on the South rim into irrigation canals that were built by the American Indian Hohokam people over 1000 years ago. Later the Sinagua people built cliff dwellings on the inside of the rim that can still be seen.
The lake at the bottom of the sinkhole has formed a unique ecosystem of plants and animals existing in a constant battle for survival. The water contains high levels of arsenic and carbon dioxide so fish cannot live there, but five species have developed that exist no where else on Earth. Amphipod crustaceans (look like miniature shrimp) are pursued by non-blood sucking leaches and water scorpions. There are also unique species of snails and single cell diatom.
The odd-looking clouds are actually smoke from forest fires in the mountains to the West.