Capt. Warren Day was, by nature, a curious sort.
A contract surgeon at Fort Verde, he was one of a long line of military doctors assigned to the fort whose inquisitiveness was sparked by the fort's unusual surroundings. Built amidst the remains of a lost civilization and a landscape inhabited by unique species of flora and fauna, Fort Verde had gained a reputation as an open-air laboratory long before Day arrived in October 1873.
But of all the curiosities in the neighborhood, few captured the imagination like the strange sinkhole, seven mile north of the fort, on the banks of Beaver Creek.
Named Montezuma Well by the American troops who first discovered it, the desert oasis's mysterious waters and lush greenery provided a refuge from the summer heat and winter cold.
The same waters also provided the lifeblood for numerous civilizations, some of whose former dwellings, scattered about the rim and cliff walls, added to its mystique.
It was the kind of place that had sparked imaginations long before the first Americans laid eyes on it.
At some point during his stint at Fort Verde, Capt. Day decided to answer a basic question that no one else seemed to know -- specifically, how deep was the ominous green pool of water at the bottom of the well.
Day scrounged about the fort and came up with several hundred feet of spare rope, assuring everyone it would take all that and possibly more to reach bottom, and headed up Beaver Creek.
When he got to the well, he and a couple of companions lashed together a primitive raft and slid out on the pond surface. He tied a rock to one end and started letting out rope. To his disappointment, Day found bottom just 65 feet below his raft.
Embarrassed that he had made such a big deal of needing hundreds of feet of rope, Day made a point of soaking the unused lengths before heading back to the fort.
When he returned, he dropped the soggy coil of rope on the ground and proudly announced to the curious onlookers, "Boys...it's bottomless."
Warren Day may have been the first person to probe the mysterious world beneath Montezuma Well, but he was not the last. Nor was he the last to bring back strange tales of the singularly unique and often eerie world below the surface.
NOTE: Video lacks sound.
For all the speculation made from shoreline, it wasn't until 1948, shortly after it became Montezuma Well National Monument, that someone actually braved the abyss and went down for a look around.
The report of diver H.J. Charbonneau seemed to verify a conclusion drawn by the famous newspaper reporter and adventurer, Charles Lummis, some 60 years earlier, that the well was a "creepy place."
Upon surfacing, Charbonneau reported the bottom was at 55 feet and composed of fine silt. He also noted the pond was thick with leeches from about 30 feet on down.
And according to a report from the park's custodian at the time, Charbonneau also said "he stepped on something soft, slimy and large, which caused him concern."
There have been nine documented dives to the bottom since Charbonneau's first decent. With one notable exception, they were all authorized and all for scientific research.
In 1954, Fritz Holmquist, a Phoenix surveyor, his son J.B. and a friend L.D. Dadisman, became the first and only unauthorized divers to sneak a peak. The three smuggled in scuba gear, and J.B. made two dives before they were apprehended.
J.B., who reported he was "bit" by one of Charbonneau's leeches, was informed that diving in the well was illegal because of its "adverse effects on wildlife."
In 1962, diver G.J. Murray became the first to report that the mysterious bottom was perhaps not the bottom.
In an article in Skin Diver magazine, Murray reported of the eeriness of swimming "in a 'bottomless pit' with thousands free swimming leeches."
Murray labeled it a bottomless pit after observing that the bottom of the well appeared as "an irregular boiling surface, like that of thin mush cooking."
Numerous other divers have since reported the strange layer of sandy sediments, describing the "false bottom" as "a white lava flow moving on top of a suspended bottom with a silica gel consistency," or "quick sand" or even "boiling oatmeal."
In 2006, a team of divers from the National Park Service Submerged Resources Center in Santa Fe, N.M., was invited to the well specifically to study the "false bottom" phenomenon.
Led by Daniel Lenihan and David Conlin, the team of divers used techniques similar to the ones used to map shipwrecks.
They confirmed the false bottom is caused by pressurized groundwater entering the bottom of the well. The considerable force of the water holds a column of "fluidized sand" in suspension (along with other objects) and also gives it its "boiling" appearance.
The density of the fluidized sand is 1.75 times that of water, which is why it lays flat across the bottom of the well, instead of mixing with the column of water above. A handful of the fluidized sand, scooped off the bottom, will literally pour underwater, back on to the well floor.
There are two columns of fluidized sand rising from two vents in the floor of the well, one to the east and one to the west of the well's center.
A probe dropped into the west vent went down 69 feet through the fluidized sand. Added to the 55 feet from the water's surface to where the sand layer starts, makes the west vent 124 feet deep overall. The east vent measured 19 feet, or 74 feet overall.
Measurements made on previous dives showed the west vent as deep 82 feet (137 feet overall) and the east vent at 40 feet (95 feet overall).
The National Park Service dive team also lowered a camera some 40 feet into the west vent and discovered it was a continual column of fluidized sand for the entire depth.
Theory and Wonder
Conlin theorizes that the depth of the fluidized sand layer from the water's surface varies five to 10 feet depending on the hydraulic pressure exerted by the well's surrounding water table, explaining the differing depth levels measured in the fluidized sand column.
"What goes on at the bottom is an awe-inspiring phenomenon that is unique in my experience. There seems to be lower ponds-within-a-pond in Montezuma Well," Conlin said. "Members of our team have spent thousands of hours underwater.
"None of us, collectively or in discussions with colleagues who have dove all over the world, have seen anything like it, nor heard of anything like it."
Of all the discoveries made during their 2006 dive, perhaps the most interesting for the dive team was the correlation of their scientific research with the traditional stories of the Yavapai and Apache people.
One day while Conlin and Lenihan were studying the well, they met a group of tribal elders, who told of stories from their past that said there was a place at the bottom. from which once something emerged, it could never return.
"It was a very interesting view for us, in all our scientific splendor, and it kept coming back to us," Lenihan said. "Everything we tried putting down those holes -- cameras, rovers, sensors -- kept being pushed back out. It was an interesting convergence of how they viewed the well and how science looks at it."