Quoted from Wikapedia...
Kalamalka Lake Provincial Park and Protected Area is a provincial park in British Columbia, Canada. Kalamalka Lake, named by National Geographic as one of the 10 most beautiful lakes in the world, is one of a handful of unique bodies of water known as "marl lakes". When the lake warms in the summer, calcium carbonate (or limestone), forms crystals that reflect sunlight and create the vivd blue and green colours. Temperature changes in the fall and the spring sometimes create ribbons of deep blue colour in the lake.
Named after the beautiful Kalamalka Lake (Lake of a Thousand Colours), this park encompasses 978 hectares of pristine natural beauty in the northern part of the Okanagan Valley. Kalamalka Lake Provincial Park, has year-round appeal, especially if you've looking for a north Okanagan getaway that doesn't involve really getting away. On the northeast side of Kalamalka Lake, this park is a well-preserved remnant of the natural grasslands that once stretched from Vernon to Osoyoos. Kalamalka Lake is unique in that it is known as a “marl” lake. When the lake warms in the summer, dissolved limestone crystallizes giving the lake a distinctive blue and green hue. When the lake cools, the limestone crystals disappear.
From the spectacular wildflower display in the spring to the relative seclusion of the beaches and boating spots in summer; from the golden-hued forests in autumn to the rolling, cross-country ski trails in winter, this park is a favourite with visitors year-round. Two interesting archaeological sites lie within park boundaries, and you may see coyote, deer, black bear, Columbian ground squirrels, yellow-ballied marmots, mink, bobcat and red fox.