Narcisse Snake Dens Trail

The Narcisse Snake Dens in Manitoba, Canada, are home to the world’s largest congregation of garter snakes, providing an extraordinary natural spectacle. Each spring, tens of thousands of red-sided garter snakes emerge from limestone sinkholes after hibernating through the frigid winter. This seasonal event, drawing curious visitors and researchers alike, highlights the unique adaptability of these non-venomous snakes, which survive in one of the coldest environments inhabited by reptiles. These dens also serve as a vital breeding site, with males and females forming dense mating balls as part of their reproductive cycle​.

Historically, the land surrounding the dens is characterized by limestone deposits, which create the ideal underground cavities for hibernation. The dens' ecological importance has made them a focal point for conservation efforts, particularly in managing the delicate balance between tourism and protecting the habitat. Interpretive trails and observation platforms have been constructed to allow visitors to witness the snakes without disrupting their natural behavior​.

Before 1999, the population of red-sided garter snakes in Narcisse was about 70,000, but a harsh winter that year killed tens of thousands before they could reach their winter dens. This event raised concerns about the snakes' migratory path, which crosses Highway 17. Each year, approximately 10,000 snakes were being run over as they crossed the road. Prior to 1999, the large population had mitigated these losses, but with the sharp decline in numbers, immediate action was needed. Manitoba Hydro and volunteers responded by building snow fences to guide the snakes into six-inch tunnels under the highway. However, some snakes still managed to cross, so signs were posted to warn drivers to slow down during the migration season. These efforts have been successful, with fewer than 1,000 snakes now being killed on the road each year.

As of 2024, the snake population has recovered, with numbers fluctuating between 75,000 and 150,000 each year.

The Narcisse Snake Dens are an ecological and educational treasure, showcasing a rare natural phenomenon. By fostering a deeper understanding of garter snake behavior and conservation, the site inspires awe and encourages stewardship of Manitoba’s unique biodiversity. Visitors are encouraged to explore the self-guided trails to witness this awe-inspiring gathering of wildlife​.