At a recent Good Morning Truckee focused on wildlife management, Will Richardson of Tahoe Institute for Natural Science shared that rattlesnake sightings around the Truckee/North Tahoe area in recent years are not, in fact, a new phenomenon. We asked him to help us sssssset everyone sssssstraight.

~ AH

Are rattlesnakes new to the Truckee/Tahoe area? How long have they been here, and what brought them to the mountains?

The first rattlesnake in the Lake Tahoe basin showed up 10 years ago, on June 9, 2015, when the El Dorado County Animal Services was asked to remove a large rattlesnake from underneath the porch of a home in the Bijou neighborhood of South Lake Tahoe, just a few blocks from the lake itself and smack in the middle of the city’s population center. This was not only the first rattlesnake call received by the agency, but this animal represented the first documented rattlesnake within the Lake Tahoe Basin that we at TINS, or anyone in the Tahoe Biologist Interagency Group, is aware of. It is important to consider that biologists have been scouring the Tahoe area, at times quite thoroughly, since the late 1800s.

This 2015 Bijou record marked the beginning of increasingly common rattlesnake reports as the reptiles expand their range over the higher mountain passes from the west. I had always assumed that rattlesnakes would come into the Basin from lower passes and drier habitat to the east, in particular the Kingsbury Grade and Spooner Summit areas, but records for the Nevada side of Tahoe are only just starting to appear in the last 2 to 3 years. However, the last decade has produced a stream of rattlesnake observations from along the Sierra Crest, in particular around the Pyramid Creek Trail, Lost Corner Mountain, Barker Pass, and Donner Summit. I predict that the Velma Lakes area will be next, and am a bit surprised that we haven’t seen any observations from there yet. The Loch Leven Lakes area lies well outside the Lake Tahoe Basin and has had rattlesnakes as long as anyone can remember, but there too they are on the increase, and in 2017 a dog was bitten there.

All of these records fit nicely into a steady pattern of increased rattlesnake sightings at higher elevations, driven by climate change and the trend toward longer, warmer summers. Last summer a baby rattlesnake was found near Fallen Leaf Lake, which clearly demonstrates that they are reproducing and expanding their footprint in the region. In 2023, I hiked up General Creek one day to see if I could find a rattlesnake, and within a few hours I had. If you are familiar with their behaviors and preferred habitat, one can find rattlesnakes around Boca Reservoir in the right conditions. At this point, one should be aware of the possibility of encountering a rattlesnake just about anywhere around Tahoe.

Thankfully, rattlesnakes just want to be left alone, and you are most likely to walk right past them without noticing. If you do get too close, they will give you a courtesy buzz. Note that if we kill the conspicuous ones, the population is more likely to stay silent and not give that warning that serves our best interests! Rattlesnakes are much maligned and feared, but they do serve a very important role in helping keep rodent populations down. Here at Tahoe, we have very high prevalences of bubonic plague, relapsing tick fever, and hantavirus — terrible, consequential diseases, all carried by rodents. These snakes can help knock down the rates of those diseases. They also are fascinating creatures with highly evolved social behaviors, pose far less danger than you might think, and deserve a place in Tahoe’s changing environment.

~ T. Will Richardson, Ph.D., executive director, Tahoe Institute for Natural Science