https://www.nps.gov/moca/planyourvisit/exploring-montezuma-well.htm
After seeing the Montezuma Castle we got back in the Jeep and headed over to the Montezuma Well. It is about 8 miles northeast of the castle. Getting to the Well takes a short hike – uphill of course – to the outer edges of it. The material they have printed says it is a 1/2 mile round-trip. The trial is poured cement and dogs are allowed. They have plenty of signage showing what you are looking at and barriers to remind you not to step over the edge. The astonishing thing about the well is it dates back at least 10,00 years! The Southern Sinagua used the water to irrigate their crops. The well was created by a limestone sink probably 10,000. It is fed by a freshwater spring. Each day 1.5 million gallons of water flows through it. Standing on the edge of the barrier you can see the dwellings built in the side of the cliff! Other structures can be found on top of the land. Archeologist believe between 100-150 people lived here.
The water contains arsenic and high amounts of carbon dioxide. No fish can live here. BUT, five species live in this Well and cannot be found anywhere else on the planet! Each night 3 of these species play a sort of “Cat and Mouse” game. The amphipod, which resembles a tiny shrimp and is no bigger than a pinky fingernail, swim near the center of the Well, just out of reach from ducks and other predator during the day. These poor guys don’t catch a break. At night, the leeches come out! They say these are not the bloodsucking kind of leech. These leeches thrive on eating the tiny amphipods. The amphipods swim to the outer edges of the Well only to be threatened by the water scorpion! These amphipods must play another game, “Quite and Still as a Mouse” so the water scorpions don’t eat them. They hang out playing the game until the sun rises. Hanging out on the outer edges, with great seats to the action, are the Montezuma Well spring snail and a special single celled diatom.
Top left – leeches Top right – Montezuma Well snail
Middle left – amphipod Middle right – water scorpion
Bottom left – diatom
Looking at the Well, it looks so peaceful. I would never in a million years guess there was life in there!