Soon after rescuers reached surviving members of the Donner Party on the eastern flank of the Sierra Nevada in February 1847, the public was bombarded with grisly details about how the snowbound pioneers had resorted to cannibalism when their food supply ran out. Thanks to letters and journals kept by members of the Donner Party and their rescuers, it has long been accepted that cannibalism occurred at the party’s main camp at Truckee Lake (later renamed Donner Lake) and among a smaller group that tried to escape the mountains to get help.

But some descendants of the Donner family refuse to believe that any such thing took place, and insist that stories of cannibalism are exaggerated. And when recent excavations of a Donner campsite at nearby Alder Creek found no clear evidence of the taboo practice, initial news reports suggested we might have gotten the story wrong from the beginning.

So what’s the truth?

The Alder Creek excavations, conducted in 2003 and 2004, turned up more than 16,000 bone fragments in all, including the remains of rodents, rabbits, deer, horses, oxen and cattle. They also found canine bones, supporting accounts by survivors that they ate their pet dogs.

It’s clear that Donner Party members went to great lengths to avoid eating their own dead: The stranded migrants consumed a glue-like substance made from boiled animal hides, along with charred bones, twigs, leaves and bark. But despite the lack of human bones recovered from the Alder Creek site, researchers concluded that cannibalism may have occurred there in the days between the departure of the first relief party in late February and the last survivors’ abandonment of the camp in mid-March. While cannibalism may indeed be part of the Donner Party story, the Alder Creek excavations help reveal the more complicated truth behind their harrowing struggle to survive, and the desperate efforts they made to stave off such a gruesome solution.