Montezuma Well, Verde Valley, Arizona

Montezuma Well has all the surprise of a lake and lush vegetation in the midst of a desert. It is a limestone sink formed long ago, still fed by continuously flowing springs. The Southern Sinagua irrigated crops with its waters. In places, you can see traces of the lime-coated irrigation ditches. The pit house here dates from about 1050. Southern Sinagua dwellings here range in size from one-room houses to large pueblos. Between 1125 and 1400 about 100-150 people lived here.

Montezuma Well rises from deep underground and flows constantly. Called Yuvukva (sunken spring) and Tawapa (sun spring) by the Hopi, Ah-hah gkith-gygy-vah (broken water) by the Yavapai, and Tu sii ch'iL (water breaks open) by the Western Apache, Montezuma Well is a holy place of emergence in some tribal histories. The water springing from primordial origins, nestled within unique geology, provides refuge to species of animals and plants found nowhere else in the world. 

Traditional stories of the Yavapai and Apache people say that once something emerges from the vents at the bottom of the Well, it can never return. Even in times of regional drought, about 1.6 million gallons of water flow through two main vents at the Well's bottom every day. The amount is fairly regular and the temperature is a nearly constant 74 degrees. Researchers have only recently determined where they believe the water originated. National Park Service dive teams continue to investigate the dark waters below. 

A very different world exists under the calm surface of Montezuma's Well. Imagine diving down into the dark green water. There are no fish. Instead, thousands of freshwater leeches swim under the Well's surface. At 55 fee, divers report that fine sand boils up in swirling, cascading mounds. In 2006 divers put cameras, rovers, and sensors into the vents.  The legend held true -- every piece of equipment they put in was pushed back out.

Without fish the lake does not have the usual lake dynamics. This unique habitat is home to creatures found nowhere else on the planet, and swimming leeches are major predators. High levels of dissolved carbon dioxide -- 80 times higher than most lakes -- make life impossible for fish, amphibians, and some aquatic insects. The Well is the world's only home for five species, including a miniature shrimp-looking amphipod, a leech, a tiny snail, a water scorpion, and a type of one-celled plant called a diatom.

Amphipods, the link between primary producers (algae) and predators, are critical to the Well's food web. During the day they take refuge in open water, deep enough to avoid predatory water scorpions and ducks, but shallow enough to avoid leeches hiding farther down from the sun. In late afternoon the amphipods take their chances and rise to feed on microscopic algae. But once the sun has set, the leeches also rise and feast on large quantities of amphipods. 

By taking advantage of this natural alcove and overhang, residents only had to build a wall across the front of the alcove with a door to have a dwelling that was cool in the summer and warm in the winter. Notice how the overhang above is blackened from cooking and warming fires. George H. Rothrock, a pioneering Arizona photographer, took advantage of this site's popularity and painted his advertisement on the rocks overhead.

This is the area at the bottom where the Well's water comes out and flows down the aquifer to a river.  It's nice and cool down here. Peaceful.