Narcisse Snake Dens

Limestone here is riddled with sinkholes and crevices that reach below the frost line, which lets red-sided garter snakes overwinter in numbers found nowhere else: tens of thousands hibernate in a handful of dens, and when they emerge over a few weeks in late April and early May the males form writhing mating balls around each female, dozens of snakes to one. It is generally called the largest gathering of snakes anywhere on earth. They disperse to the marshes for summer and return in September. The snakes are harmless, and viewing platforms and a short trail circuit the four main dens.

The landscape

• The mating balls - dozens of males coiled around single females.
• The four dens - limestone sinkholes on a short interpretive circuit.
• The emergence - tens of thousands of snakes above ground at once.
• The autumn return - a smaller gathering as they come back in September.

When to go

Late April to mid May is the whole point; timing shifts a week or two with the spring and the site publishes updates. A smaller and less dramatic return happens in early September.

Things to know

Outside the few weeks of emergence there is essentially nothing to see. Timing varies each year with weather. The snakes are harmless but the sight distresses some visitors.

Nearby

Oak Hammock Marsh lies south; Winnipeg is beyond it.

Key facts