Bear Lake is a natural freshwater lake on the Utah-Idaho border in the Western United States. It is the second largest natural freshwater lake in Utah and has been called the "Caribbean of the Rockies" for its unique turquoise-blue color, which is due to the reflection of "limestone deposits suspended in the lake." Its water properties have led to the evolution of several unique species of fauna that occur only within the lake. Bear Lake is over 250,000 years old.