Dave’s Blue Hole is an unusually deep freshwater spring located outside of Gunsmith, Colorado. The actual measure of the hole is unknown; the last attempt bottomed out at 115 meters before the surveyor ran out of line. The water becomes anoxic at about 43 meters. After the incident of 1988, the spring has been capped indefinitely by a metal gate. Dave’s Bait & Wait remains standing beside the entrance to the pool, abandoned after tourism dropped off completely.
The first recorded description of the spring comes from a Spanish traveler’s diary dated 1796. The writer, a Franciscan friar on his way to San Carlos, detailed a stop at a place sheltered by high bluffs. Within the cliffs, they found an unusually round spring that produced clear, crisp water. Another member of the traveler’s group fell into the spring and sank out of sight almost immediately. The group cast lines into the hole to no avail. What’s more, they found through experimentation that the water had almost no buoyancy. Light things like sticks and even folded paper would not stay on the surface for more than a moment.
The traveler also noted the existence of a petroglyph on the bluff immediately above the spring, depicting a whale-like creature. The petroglyph has been all but worn away in the intervening centuries. The rock where it sat now contains only a few faint lines.
The parcel of land where the hole lies was purchased by one David Killigan in 1860 for the princely sum of $.35 per acre. He initially intended to mine for silver but found the novelty of the hole too striking to pass up. He built a store in hopes of attracting travelers en route to the rockies, touting the supposed restorative powers of the spring. The place became a local fixture, Killigan a tolerated eccentric that added color to the countryside. When he disappeared in 1876, it raised a mild furor. Killigan’s lantern was found placed beside his shoes at the rim of the spring. A line was secured to the nearby horse-hitching post and led down into the water, upon retrieving the line they found it had been tied into a series of knots to serve as a ladder. Neighbors in town had heard him complaining of mild temblors coming from inside the spring just a few days prior. He had possibly entered the waters in hopes of discovering the source of the noise and fallen prey to a thermocline.
The shop passed from hand to hand over the years. It was a solid tourist draw, so the operation was run by an official town trust. The spring drew no more unusual interest until the onset of recreational diving as a pastime.
The spring had long been a draw for thrill-seeking divers when Mark Boyle attempted his descent on June 5th, 1988. The anoxic nature of the spring meant that many animal skeletons littered the walls of the hole. Divers who ventured past the indicated safety zone spoke of human skeletons glimpsed at greater depths, in numbers that might suggest human sacrifice. The spring had been equipped with a submerged gate that warned divers that venturing past that point was unadvisable. Mark’s plan that day was to do exactly that.
Mark had brought along two friends and a safety line as guards against a possible accident. Neither friend was diving-certified, nor did they have diving equipment.
At 3:07pm, Mark went over the side of the spring.
At 3:46 the safety line began trembling. Mark’s friends became alarmed.
At approximately 4pm, the safety line went taut. Mark attempted a rapid ascent, too rapid. He showed signs of decompression sickness when he surfaced, slurring his words and lacking coordination. As one friend raced to call an ambulance, the other attempted to administer first aid. Mark rambled about something that lived in the waters of the spring, that the spring was really just a small outlet of a much-larger subterranean body of water. He was incoherent when the ambulance arrived. He fell unconscious on the way to Gunsmith’s only hospital and died a few hours later.
After an inquiry, a second gate was set on the mouth of the spring and welded in place. Through possible corruption due to metals fallen into the spring, the water has taken on a corrosive effect. Seismic activity in the region has increased steadily since 1988.