Little Limestone Lake

Little Limestone Lake is generally described as the largest and finest example of a marl lake in the world. The water holds dissolved calcium carbonate from the limestone bedrock, and as it warms through the day the mineral comes out of solution as microscopic calcite crystals that suspend and scatter light, turning the lake from clear blue in the cool morning through turquoise to an opaque milky aqua by afternoon, then back as it cools. The change is visible within hours. It is now protected as a provincial park. There are no facilities beyond a roadside pull-off.

Highlights

• The colour change - blue to milky turquoise across a single warm day.
• The calcite bloom - crystals suspending in the water as it warms.
• The limestone shore - pale rock and clear shallows at the edges.
• The roadside viewpoint - the only developed access on Highway 6.

When to go

June to September, on a warm sunny day, which is what drives the effect; cool or overcast days show little change. Afternoon shows the strongest colour.

What to expect

The effect needs sun and warmth; a cloudy visit shows an ordinary lake. It is a very long drive north of Winnipeg with almost no services. There are no facilities at the site.

Nearby

Grand Rapids lies south; Pisew Falls is north.

Key facts