Buzz
Canada often appears as a serene and peaceful destination—think crystal-clear lakes, polite locals, political inclusivity, and an abundance of apologies. It’s not the kind of place you’d associate with an overwhelming number of snakes lurking beneath the surface. However, that perception changes if you visit Narcisse, Manitoba.
Each spring and fall, this region becomes home to the largest snake gathering on Earth, attracting global attention. For a period of one to three weeks near Highway 17, tens of thousands of red-sided garter snakes emerge from limestone crevices in search of mates. They gather in rocky pits, intertwining to create massive, dynamic snake formations that can stretch up to 20 feet wide. The scene is accompanied by the distinct sounds of hissing and the rustling of scales.
The unique geology of the area explains this extraordinary phenomenon. With winter temperatures in Manitoba’s Interlake region plummeting to nearly -50 °F, the limestone fractures and erodes due to freezing and underground water, creating caverns and sinkholes. These natural shelters become dens for cold-blooded snakes, providing refuge below the frost line during harsh winters. However, the limited number of suitable dens forces the snakes to converge in a single location.
J Hazard via Wikimedia // CC BY-SA 3.0
After completing their spring activities, the garter snakes disperse from their dens along the highway to nearby wetlands, where they spend the summer soaking up the sun. In the fall, they return to Narcisse, retreating underground to repeat the cycle.
With up to 50,000 snakes involved, the mating process can become quite complex. Garter snakes rely on pheromones, but males sometimes emit both male and female pheromones to confuse rivals and steal their body heat—a valuable resource after months of hibernation in freezing conditions. Males also form mating balls, where dozens of snakes compete for a single female. As Bob Mason, chair of the biology program at Oregon State University, described in a National Geographic video, it resembles “a sea of living spaghetti” in a sinkhole the size of a living room.
Despite the current spectacle, the red-sided garter snake population once faced significant threats. In 1999, harsh weather and highway crossings led to the deaths of tens of thousands of snakes before they could reproduce. The installation of tunnels under the highway and snow fences to guide the snakes, along with warning signs for drivers, has drastically reduced fatalities. Today, fewer than a thousand snakes die on the road annually.
The site features four snake dens and is visitor-friendly, with walking trails, viewing platforms, and restrooms. Garter snakes are harmless and gentle, making them safe for children to handle. This has made the Narcisse Snake Dens a popular destination for families, especially since the snakes’ spring emergence often coincides with Mother’s Day.
