A little more than five years ago, a herd of 122 mule deer fell to their deaths in the mountains of Central California. The pictures from that day are gruesome: dozens of dead deer strewn across a steep boulder field at the bottom of an icy chute. Some of the carcasses are contorted or splayed open. Others are pinched and piled at weird angles among the rocks.<\/p>\n
\nOne photo in particular shows an unnamed hiker kneeling next to a doe with a pocketknife in their hand. What that photograph doesn\u2019t show is the hiker rock-hopping across the boulder field, mercifully slitting the throats of the mortally wounded deer. (This anecdote was shared by several users across multiple online forums<\/a>.) <\/p>\n Mass mortality events like the one that occurred in the John Muir Wilderness aren\u2019t all that uncommon. Every year, landslides, floods, avalanches, wildfires, and other natural disasters kill countless critters throughout North America. We\u2019re just not always there to watch it happen.<\/p>\n Still, seeing the photos from 2017 resurfacing on social media makes us wonder: How often do large groups of wildlife fall to their death in the mountains? And what really happened that November in the Sierra Nevada?<\/p>\n Concrete information about the 2017 mass mule deer death is limited. If there ever were<\/em> any official reports in national news outlets, they\u2019re buried somewhere deep in the bowels of the internet. The California Department of Fish and Wildlife didn\u2019t put out a press release that year, and the acting information officer for the region says he was not working for CDFW in 2017 and has no knowledge of the event.<\/p>\n There was, however, a story published in The Sheet<\/a>, a local alt-weekly paper based in Mammoth Lakes, California. There\u2019s also a well-reported article in the Sierra Nevada Bighorn Blog<\/a>, along with a handful of informative posts in a forum<\/a> dedicated to outdoor recreation in the Sierras. Pieced together, these sources give a pretty good account of what happened in early November of that year.<\/p>\n According to these reports, the group of mule deer was making its annual migration from their high-elevation summer range on the west side of the Sierra Crest to their winter range on the eastern side of the mountains. The deer were part of two large herds in the area: the Round Valley herd, which had an estimated population of 2,800 at that time; and the Goodale herd, which was closer to 5,500 strong. The deer were following their traditional migration route through Inyo National Forest. This route took them across a pair of notoriously dangerous stretches known as Bishop and Shepherd Passes, both of which are at elevations of around 12,000 feet.<\/p>\n Most of the mature bucks and does had made this trek before, but that didn\u2019t mean they were prepared for the conditions they would face that fall. Calling the winter of 2016-17 a big snow year in the Sierras would be an understatement. It was actually the wettest winter on record at the time, according to the Weather Channel<\/a>. This meant that even though the deer had waited until fall to cross the passes, there was still plenty of snow on the ground in November. And after months of high-elevation temperature swings, which create what\u2019s known as a freeze-thaw cycle, the snowfields were coated with a bulletproof sheet of ice.<\/p>\n What happened next requires little imagination.<\/p>\n \u201cThe deer were following their migration trail and because of the heavy snow we got last year, there were big fields of it left unmelted. When it got cold it turned to ice and the deer just slipped to their death,\u201d CDFW wildlife biologist Mike Morrison told the Sheet. \u201c[Mule deer] are like lemmings. They could go around it, but their mama brought them that way and that\u2019s the way they\u2019re going. They step on the ice not recognizing it\u2019s going to be slippery. When they get to the point where gravity takes over, it\u2019s too late.\u201d<\/p>\n In addition to being well-worn game trails, both Bishop and Shepherd passes are popular mountaineering routes. If they weren\u2019t, CDFW officials likely never would have heard about the mass mortality event.<\/p>\n Lindsey Jackson is one of the hikers who witnessed the immediate aftermath at Bishop Pass. After stumbling upon the 78 dead deer that littered the bottom of the pass, Jackson notified the agency on Nov. 11. (It\u2019s unclear if Jackson is the hiker pictured in the unattributed photograph that the Sheet published on Nov. 22.)<\/p>\n \u201cWhen I first walked up on it, I was horrified,\u201d she said in an interview with the Sheet.<\/p>\n The next day, another mountaineer called CDFW to report the dead deer they\u2019d seen at Shepherd Pass. The agency\u2019s investigation determined that another 44 mule deer had died at that location, making a grand total of 122 deer that fell to their deaths in both passes.<\/p>\n Morrison also explained to the Sheet that while these mass mortality events might not happen every year, other mass mule deer deaths have been documented before in the exact same location.\u00a0\u00a0<\/p>\nIce + Gravity = 122 dead mule deer<\/h2>\n
History Repeats Itself<\/h2>\n
![\"mule](\"https:\/\/www.outdoorlife.com\/uploads\/2023\/01\/06\/mule_deer_mass_mortality_2017_2.jpg\")