Water runs from the main Montezuma Well to this pool. (Lisa Schnebly Heidinger)

Montezuma Well

Lisa Schnebly Heidinger

Even those of us who try to be aware of stereotypes sometimes find out we have them. And that’s not a bad thing.

One of my favorite things has been to show people who have never visited Arizona how much it goes against their expectations. In 48 hours, someone can be picked up at the Phoenix airport (which despite the lyrical name Sky Harbor does look as you’d imagine: some cactus and desert vegetation on a canvas of unrelenting tan), and whisk them through desert to ponderosa forest, into the Grand Canyon, point at the permafrost geologic zone on our way past the San Francisco Peaks, walk the spare Painted Desert landscape of Reservation Country, and dip down into Oak Creek Canyon for red rock views on the way back to the airport.

View of Montezuma Castle. (Lisa Schnebly Heidinger)

So I was fairly complacent in my belief that I grasped what our biological diversity encompasses. But fortunately, there are always surprises. One is Montezuma Well.

Named by a branding-aware explorer during the 19th century, this is a limestone sinkhole in Verde Valley, appearing possibly manmade because of its smooth oval shape. Finding ruins in a nearby cliff wall, the optimistic explorer opined it could be of Aztec origin and gave both Montezuma names, Well and Castle, which first appeared in the 1878 “Handbook to Arizona.”

For many, the Verde Valley is a gas-and-coffee stop between Phoenix and Flagstaff on Interstate 17. But Montezuma Well bestows upon it a little-known superlative:

Montezuma Well has the highest concentration of unique species in North America.

And nature’s redness in tooth and claw pits one of these against another: the Montezuma Well water scorpion feeds upon the Montezuma Well amphipod, causing the second of those two to laboriously swim out to the middle of this body of water and sink 10 to 15 feet below the surface to avoid being eaten. Another unique species, the Montezuma Well leech, may have evolved from one transported on the foot of a duck migrating from Mexico. (A Montezuma Well diatom and Montezuma Well springsnail complete the roster.)

Behind the pool you can find beautiful hanging gardens. (Lisa Schnebly Heidinger)

All this comes from Larry Stevens, who is Curator of Ecology at the Museum of Northern Arizona. He is a treasure trove of information about Montezuma Well, including the fact that it is carbonated and has high levels of arsenic, which contribute to the uniqueness of species able to live there. (He opines that it also may help explain why the elaborately constructed ruin called Montezuma Castle was abandoned; that water used on crops over a period of time may have impacted the health of the Sinagua natives who lived and farmed there.)

For years local lore held that no one knew how deep the Well was, but it became the first place the National Park Services used scuba gear in 1948, putting a number to the mystery bottom: it’s 55 feet down. However, despite tests using gas and dye, the source of the water hasn’t been definitively pinpointed. And it’s a lot of water: underground springs send more than 1.2 million imperial gallons of 75-degree water up and out of Montezuma Well each day.

While it’s warm around the well, right behind it where the water flows out into a canal that dates back 1,000 years, massive curving sycamores create shade that drop the temperature 20 degrees. Between the smooth behemoth trees, the sound of water, and plenty of places to sit, it’s a perfect place to take a brief respite and contemplate the myriad of surprises in nature.


Lisa Schnebly Heidinger is a native Arizona author, whose ten books highlight various aspects of her beloved state.

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