When we think of nature’s masters of disguise, chameleons often come to mind. But did you know that some non-living wonders can also transform their appearance? Meet the marl lakes, bodies of water so rich in minerals that they change colors with the shifting weather. Hidden within Canada’s remote reaches is Little Limestone Lake, a marl lake conspicuous for its size and mesmerizing hues.
By: Mason Harris
Date: 19:54 24.02.25
Last Update: 11:58 02.04.25
Marl lakes are geological oddities known for their ability to change color dramatically with temperature fluctuations. This phenomenon occurs when calcite, derived from dissolved limestone, reacts to shifting temperatures. As the water warms, microscopic calcite crystals form, casting a milky turquoise hue over the lake. When the water cools, the crystals dissolve, leaving the water crystal clear. These lakes are exceedingly rare, and none are as impressive as Little Limestone Lake in Manitoba.
Tucked away in the northern Manitoba Lowlands, about 500 kilometers north of Winnipeg, Little Limestone Lake holds the hefty title of the largest marl lake on Earth. It lies within the 4,095-hectare Little Limestone Lake Provincial Park, a protected area dedicated to preserving this natural wonder. While the park is nonoperational, or, put simply, it lacks the typical visitor amenities, its exceptional scenery makes the journey well worth the effort.
Anyone making the arduous trip here will have the chance to witness the lake’s appearance shifting from dull grayish-blue to an almost tropical aquamarine in a matter of hours. On hot summer days, the marl levels rise, and the water takes on a striking milky turquoise shade, offering a somewhat surreal, Caribbean-like vista in the middle of Canada. In winter, when temperatures can plunge to -40 degrees Fahrenheit (-40°C), the lake transforms once again, its waters becoming crystal clear as the marl recedes.
Beyond its color-changing quirk, the lake’s surrounding forests and wetlands host a diverse array of wildlife, including bears, lynx, moose, and the threatened woodland caribou. The lake itself supports species such as walleye and whitefish, while eagles and songbirds thrive in the area’s rich ecosystems. The landscape also features classic karst geology, with sinkholes, caves, and peculiar rock formations sculpted by centuries of water erosion.
Visitors who make the trek to this hideaway often find themselves enveloped in a sheer sense of isolation, a stark contrast to the hustle and bustle of modern life. While the park remains largely undeveloped, those who honor the “leave no trace” principles play a crucial role in preserving this natural treasure for generations to come.
photography by: Bluejaywpg/ Wikimedia Commons
