Since mankind ever first set eyes to the vast seas and the horizon beyond which they could not see, islands have remained firmly entrenched within stories of the mysterious and the bizarre. They hold a certain mystique to them; patches of land ensconced by water, isolated yet brimming with their own vibrant energy and sometimes deep mysteries or even horrors. One island lying just off the coast of Mexico was right up until modern times considered a desolate no-man's land, where only the brave dared to tread and from which most of the foolhardy who tried failed to return. It is a place pervaded by legend, ominous mysteries, and persistent dark rumors that it is a place of cannibal warriors who have a habit of erasing people without a trace. Here is the island of sharks, and it is has never been for the feint of heart.

Lying within the Gulf of California is Tiburón Island, or in Spanish Isla del Tiburón, with the word Tiburón being Spanish for “shark.” Located in the Midriff Islands chain, it is Mexico’s largest island and is the home of a vast nature preserve featuring several unique species found nowhere else on earth, as well as large untapped natural resources. The largely uninhabited Tiburón Island is the ancestral land of several bands of the native Seri people of the area, who continue to administer the island as an ecological preserve and manage the limited hunting that is allowed there, as well as various hiking and camping permits. It is also home to some interesting history that is at times steeped in ominous mystery.

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Tiburón Island

A hot, barren moonscape of a land comprised mostly of desert scrub, the island is an unforgiving place in many respects. The arid, desert landscape is filled with numerous dangers such as the relentless heat, lack of available fresh water, poisonous snakes and scorpions, and the channel between it and the mainland is a shark infested stretch of water dotted with shoals that churns with strong tides that are so perilous they have earned it the name Canal del Infiernillo; "Hell's Channel." In addition, the native Seri people were once seen as vicious, beast-like savages, and numerous dark rumors surrounded them, such as that they did not use fire but rather ate food raw and bloody, that they would attack visitors on sight without provocation, and that they were unrepentant cannibals. It was partly because of these insidious hazards that Tiburón Island remained a fairly remote place well into the 1900s, yet rumors that it harbored vast stores of gold and other precious metals offering untold riches were enough to compel and lure some brave explorers to venture there.

Stories of people approaching Tiburón Island never to return abound, with an untold number of people never returning from this desolate land, and the rumored bloodthirsty Seri people featured heavily in such tales. One such case was a journalist named R. E. L. Robinson, who in 1894 embarked on a planned 6 month mission to study the ways of the island’s mysterious and little understood natives. There was an ulterior motive involved, as apparently Robinson meant to fake his death in order to appear as though he had been killed by the Seri. Unfortunately for him, it seems that this was exactly what was to happen. After hiring a boat to bring him to the island, Robinson reportedly walked ashore and was promptly attacked by the bloodthirsty natives. According to the boatman who was waiting just offshore, Robinson fired his pistol once before falling under the deadly onslaught of a hail of arrows. This story fit in very well with the public perception of the Seri as primitive, untamed savages, and there were occasional similar reports of adventurers going ashore only to be mercilessly killed and even eaten by the Seri.

In one bloody account from 1904, two fugitives from the Mexican mainland fled to Tiburón Island, after which the governor of Sonora state, in which the island is located, sent an emissary to the Seri people. In this case the natives did not immediately attack, and actually purportedly watched quizzically as the messenger used various gestures to communicate that the governor was prepared to offer a reward if the Seri would kill the two fugitives. Showing that they were every bit as ruthless as their reputation suggested, the Seri then went out into the badlands and returned with the fugitives’ dismembered hands tied to a pole.

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A Seri native of Tiburón Island

Some of these adventurers went to the island only to vanish off the face of the earth, and leave mystery in their wake. In 1896, a Captain George Porter made a natural history expedition to Tiburón Island aboard a junk. He never returned and a search party comprised of armed Mexican Army personnel was sent to scour the island for the missing captain. The search party reportedly was only able to find the barest traces of the missing man, in the form of the remnants of a large campfire, which was ringed by a single shoe and a jagged piece of the stern from the junk. Although no other sign of Porter was found, it was immediately presumed that he had been killed by the Seri and eaten, cooked there right at the fire.

One intrepid vanished explorer who had an eye on the rumored gold of Tiburón Island was Arizona prospector Tom Grindell, who first approached the island in 1903. Braving the perilous currents, sharks, and the threat of native arrows flying at him from shore, Grindell merely skirted the island on this expedition, trying to ascertain if it would be possible to go prospecting there and weighing up any potential major setbacks or dangers. Deciding that it would be worth the risk, Grindell returned to Tiburón Island in June of 1905 along with companions G. Olin Ralls, Jack Hoffman, David Ingra, and a local guide, Dolores Valenzuela, as well as assorted supplies for prospecting. Although they were expected to be back no later than mid-August, three of them would never be heard from again.

By all accounts the expedition was rough from the start. They had not brought enough water, and although they had brought a contraption for distilling seawater it did not work well. The rough, eternally sun scorched terrain made progress slow, with the expedition ever wary of the supposedly cannibalistic Seri natives lurking in the wilds, and the guide became so frightened that at some point he refused to go any farther and headed back to the coast. The group then tried to seek assistance in a cattle ranch that was rumored to be on the island, but they could find no evidence that such a ranch had ever existed. Without a guide and with their food supplies and meager supply of water dwindling, they found themselves in a remote, inhospitable terrain with few options. One by one expedition members ventured out into the desert in search of water or to scout ahead, only to go missing without a trace.


The expedition member named Hoffman found himself wandering alone out in the desert and along the coast, where he managed to precariously survive for four months on turtle eggs, birds he managed to shoot with his rifle, fish, jellyfish, anything he could find, and stalked by coyotes and scavengers waiting for him to die the whole way, eventually wandering aimlessly for 150 miles over perilous terrain on foot before he was found in an emaciated, highly dehydrated, feral-looking state by some Mexican fisherman from Guaymas. One newspaper, the Boston Evening Transcript, would later describe him at the time: “half insane and without clothing, he reappeared among men, as startling an apparition as one come from the tomb.” The bedraggled, ghoulish looking shell of a man was surprised to later be told that nobody else had been found from the doomed expedition except for the guide, who had managed to escape back to the mainland.

Several searches for the missing expedition members commenced, the most extensive of which was led by Tom Grindell’s own brother, Edward, who enlisted the help of the original guide Venezuela, as well as one of the sole survivors of the ill-fated expedition, Hoffman. Neither of the two men had a clue as to what had become of the other expedition members, but news came in from Papago hunters on the island who claimed that they had witnessed the sight of a brutal massacre of a group of white men carried out by the sadistic, cannibalistic Seri natives. Edward Grindell would say of the news:

The day after I arrived in Caborca a report was brought to the town that Papago hunters in the vicinity of Tiburon had found a place where some Americans had been killed and eaten by the cannibals of the island. Nothing was left of the unfortunate whites but the hands, and these were nailed to a plank stuck on end in the ground. There were also dance rings in the soil around, showing where the cannibals had had a feast. The Papagoes also reported finding a tin camp-stove and broken cameras. Many people thought that this gruesome discovery explained the fate of the Grindell party, but still I would not give up hope.

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The landscape of Tiburón Island

This was all a very common report of what the Seri did with those unfortunate to be captured by them, and rumors quickly spread out that the Grindell expedition had been mercilessly attacked and eaten, but Edward was not dissuaded. He commenced to push forth into the harsh island to try and ascertain for himself what fate had befallen his brother and his travel companions, unwilling to give up hope that perhaps they were still struggling to survive somewhere just as Hoffman had done. When the search was set to commence, along with the original Grindell expedition guide Venezuela, the guide was a no-show, and rumors came to Edward that Venezuela was a coward who had deserted the Mexican Army and was notorious for attempting to kill a rancher. Edward became suspicious of the guide, thinking that he may have even been directly responsible for the disappearances but when confronted Venezuela was adamant that he intended to help but was fearful of what Mexican authorities would do to him for abandoning the original expedition.

Although suspicious, Edward was able to convince Venezuela to go part of the way with him due to his being the only one who might have a good idea of where to look, and went ahead with the expedition with the aid of a miner named Fred Christy and an entourage of twelve heavily armed Papago scouts to fight off any hostile natives. Amazingly, after following the trail of the Grindell expedition they were able to find the remains of the fire and the dance rings that the hunters had spoken of, complete with desiccated human hands attached to a piece of wood just as described, with one of the hands having a camera strap still attached to it, flapping in the wind. Edward Grindell would say of the macabre sight:

There were two dance rings, one inside the other; the larger one was about forty feet in diameter and well beaten. At one side, and about a foot from the edge of the ring, there was a sawn plank, evidently driftwood, some fourteen feet long, firmly planted in the soil. Nailed to this plank crosswise, six feet from the ground, was a stick four feet long. At each end of this stick was a human hand, fastened there with leather straps cut from a camera case. On the inside of the straps were letters which evidently formed parts of the name of the owner; a capital  'M ' and a small  'e ' and  'r ' were noticeable. There were also some printed pages from a book on navigation tacked on the plank, and near by was a small tin stove. The savages, I should explain, tie their wretched victim to this plank and, as they dance, first one and then another will cut a piece of his flesh off, keeping up the horrible business to the tune of a doleful tam-tam ( a kind of musical instrument) and their own chanting until death puts an end to the prisoner's suffering. And it was into the hands of these fiends that I feared the explorers had fallen!

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A group of Seri natives

At first the grim discovery dashed all hope that any of the expedition would be found alive, but closer examination of the remains proved that they were not in fact those of anyone on the Grindell expedition. They came to the conclusion that the remains in fact belonged to a different group of miners, possibly a pair of men from Los Angeles named Harry E. Miller and Gus Olander, who had vanished without a trace in 1905 after going prospecting on Tiburón Island and never seen again. It seemed that one mystery of the island was solved, but the whereabouts of the lost Grindell expedition remained elusive.

The party continued their search with renewed hope, but had some setbacks in the form of heavy rains that served to erase the scant trails they had been following. Nevertheless, they managed to come across some evidence of the lost expedition in the form of abandoned camps they had used. In these camps were found some dead, half-skeletalized pack animals, as well as various scattered items such as a discarded rifle, bucket, and a book owned by Grindell, but no trace of the men themselves. Ominously, tracks from Seri natives were often found in the vicinity, some of which seemed to have trailed Grindell, which only asserted the guides’ theory that the men had undoubtedly been killed and butchered by the savages, or at the very least taken prisoner to await some unknown fate. The search expedition would ultimately cover hundreds of miles, scouring the barren, unforgiving landscape for any sign of the missing expedition members but they found no bodies, no bones, no scraps of clothing, nothing. Edward Grindell would lament:

We searched the entire coast of the mainland in front of Tiburon Island for a distance of one hundred miles, and back into the mountains for from twenty to thirty miles, and I think I have covered every place where bodies might reasonably be expected to be. We rode over eight hundred miles on horseback. I have given up ever finding the boys, but as a last resort I have offered a reward to the Papago Indians of $200 for each of the bodies they find. It is my opinion that the boys wandered in their frenzied condition away back into the mountains, into places where they never will be found.


It was as if the entire expedition had simply ceased to exist. It became international news at the time, spurring all kinds of speculation. Theories swirled as to what had become of the vanishing expedition, the most popular that they had been killed by the violent and untamed ferocious natives. Others thought they had been attacked by wild animals or had found a way to leave the island in the end. Hoffman himself believed that the expedition had simply succumbed to dehydration and died out in the stark wilderness. Several other search expeditions were launched, including one by the Arizona Rangers, but none of them could find a trace of the lost men.

The mystery would remain until nearly two years later, when a group of prospectors from California stumbled across a pile of bleached bones upon the cracked, parched, sun-beaten earth. Based on some faded, nearly illegible but readable letters it was assumed that these were remains from the lost Grindell expedition. Although the state of the remains made it difficult to tell what the exact cause of death had been, it was widely believed that it had been dehydration, just as Hoffman had claimed. Still, the more popular consensus among the general public was that the expedition had been ruthlessly slaughtered by the island’s evil cannibals and their bones left to the ravages of the desert, just as it was said they had done with an unknown number of other hapless people who had ventured there.

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An Arizona Ranger on the hunt for the lost Grindell expedition

There has been quite a bit of debate as to whether cannibalism was ever really practiced by the Seri Indians of Tiburón Island. Indeed when approached today they are said to be quite friendly and generous hosts, not threatening in the slightest, who seem to be a peaceful, courteous tribe far removed from the common image as snarling, raw flesh-eating savages, more like animals than humans, that they were depicted as being in the past. There is no evidence that they ever ate human flesh, although the Seri were rather known as fierce warriors in battle that were described as being vicious berserkers when in hand to hand combat, often seen to bite and claw at their enemies. It is perhaps this bestial ferocity and the legends that sprang from it that seeped into the media and were sensationalized to make the Seri out to be cannibalistic wild men. Add to this the many disappearances reported from Tiburón Island, probably more likely due to the harsh terrain, and it made for a spooky story of a remote island of cannibals that swallowed people up to capture the imagination. Although their reputation as merciless, feral cannibals has stubbornly endured, to what extent the Seri ever actually ever really engaged in this sort of  behavior or what role they had in the disappearances here remain unknown.

Indeed there are many unknowns still surrounding Tiburón Island. Many of the hunters, explorers, and prospectors who came here to vanish forever have never been found, and it is a mystery as to what exactly happened to them. Even in the case of those whose remains have been discovered, such as is the case with the Grindell expedition, it is not totally clear just what happened to them or what caused their deaths. The Seri people themselves remain a conundrum, cloaked in the shadows of a violent past, legend, and rumor. Whatever horrors were perhaps caused by their people have been lost to the sands of time, just as surely as the landscape is obscured by the sand of the relentless desert winds.

Perhaps we will never know what happened of the adventurers who made their way to this island of danger and sinister threats. Perhaps this is a land that in a sense still remains just as isolated as it had ever been, keeping its secrets close and eluding any clear answers. Islands are a world unto their own, out among the waves and harboring their own secrets, possible dark happenings or unspeakable grotesqueries, that are just as remote as the land they sit upon. Just off the coast of Mexico is one such place; teeming with strange rumors of savage cannibals, unexplained disappearances, and tales of adventure and hardship. Whether we ever know the full extent of the strange history of this place, it will remain a curious entity lying out across the waves, calling to us like other mysterious islands before it.

Brent Swancer

Brent Swancer is an author and crypto expert living in Japan. Biology, nature, and cryptozoology still remain Brent Swancer’s first intellectual loves. He's written articles for MU and Daily Grail and has been a guest on Coast to Coast AM and Binnal of America.

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