Pavilion Lake, lake, 3.6 mi (5.8 km) long, 2,625 ft (800 m) wide, and 213 ft (65 m) deep at its maximum depth, in Marble Canyon at the S end of the Marble Range near Cache Creek, S British Columbia, Canada. The cold, high-altitude lake is notable for large corallike stromatolites formed by microbialites, a type of microorganism that was common 2.5 billion to 540 million years ago and is believed to have been critical to the development life on earth through the production of oxygen. Microbialites generally thrive in extreme environments. Their presence in Pavilion Lake has enabled scientists to study more readily them, and the lake, along with nearby Kelly Lake, which has similar conditions, is the site of a research project funded by NASA and the Canadian Space Agency, which also explores research techniques that might be used on other planets. The lake became part of Marble Canyon Provinical Park in 2001.