To go the final distance, four men split off and forged ahead. They were never seen again.
A second party of four set out for the islands, this time against the captain's wishes. They were given their share of the food and supplies, but according to carpenter John Hadley, Bartlett denied them a crucial resource.
"Not one dog," the captain said. "If you go off and leave us, you play dog yourself." But even if it meant man-hauling their own sleds, the four decided they would rather take their chances than wait.
Ten days later, one of the captain's men -- returning from helping the first advance party -- ran into this second group as it headed out and saw them struggling badly. Anthropologist Henri Beuchat, trailing behind and nearly frozen to death, seemed to have given up all hope of surviving.
Those four men were also never seen again.
Nevertheless, the only thing the rest of the group could do was try to reach land, with as much of their supplies as they could manage.
On February 24, after staying up all night making final preparations, Bartlett gave the order to move out. With their 800-pound sleds, exhausted dogs, brief daylight, recurring blizzards and jagged mountains of ice to climb over, each mile would be arduous.
"Almost every foot of the trail had to be hewn out of the ice, like making the Overland Trail through the Rockies," Bartlett wrote. To get over the ice cliffs, "sometimes we had to get the sledges up on a ridge 50 feet high, with an almost sheer drop on the other side."
The most imminent danger was the risk of breaking through the ice. A pair of explorers who went ahead as scouts fell in up to their waists in icy water. "They started across a patch of young ice and got about 10 feet from the strong ice when their sled broke through," Hadley wrote. "The next day they got back to us more dead than alive."
Another time, it cost them a sled and all its supplies when two men broke through. "They were able to climb on the ice, but left the sled and dogs to sink where they were," Hadley reported.
Eventually eight dogs were lost, leaving barely enough to pull the sleds.
Deadly predators, a mysterious illness
Another danger that could appear at any time was the polar bear.
Hadley chronicled three alarming encounters, one of which had a bear come within six feet before he noticed the dogs growling and their hair standing up stiff.
"If the dogs hadn't smelt it, I should never have known what hit me, I guess," he wrote. The bear "had blood in his eye, and went for the dogs as if bent on murder." Hadley scrambled for his gun and "gave it to him in the head."
Even turning in for the night could bring new risks. One group thought they picked a safe spot to sleep, but "the next morning at daylight they found they were adrift with water all around them," Hadley wrote. Luckily, "after drifting a few hours, their cake touched the pack and they were able to get off."
The party reached Wrangel Island on March 12, with enough food for only two months and only enough for the dogs for a couple of weeks.
Worse still, the men were also handicapped by injuries and illnesses.
One man suffered from a knee injury and could barely walk, and another underwent a gruesome toe amputation with tin snips.
But the crew's worst affliction was a mysterious illness, causing weakness and swelling, that remains unexplained to this day.
The survivors had hoped to push on to Siberia's coast, in another forbidding trek. But their injuries and illnesses made such a grueling and hazardous trip impossible. Also there weren't enough dogs left to pull supplies for a monthlong journey -- especially when the dogs would have to haul the sick and injured as well.
Bartlett weighed the risks and made a difficult choice.
He decided to take seven dogs and just one other man, an Eskimo named Kataktovik, to try to fetch help.
The rest of the men set about surviving as best they could. Even if Bartlett survived the trek and could launch a rescue effort before the seas froze again, it would be months before a lifeline could arrive.
The men Bartlett left behind sometimes succeeded in hunting seals or birds. But as their ammunition was limited, their luck with seals ran out. The group's canned food stash dwindled, and arguments broke out about the fair distribution of rations.