Picturesque Lake McDonald colorful stones
Located right on the border with Canada, the Glacier National Park in Montana covers more than 700 lakes. Meanwhile, about 200 of them are more than five acres in size, and a dozen lakes exceed a thousand acres, which is extremely unusual for mountain lakes. In addition, the water of the lakes is surprisingly clear and clean due to low temperatures, which hinder the growth of plankton. Here you can easily see the bottom of the lake at a depth of 10 meters or more.
However, one of the most striking features of some lakes is the colored pebble covering their bottom and shores. The stones as if painted in a variety of colors, from dark red to green and blue. Meanwhile, the brightest in this regard is the McDonald Lake in the west side of the park. Lake McDonald is the largest of the lakes of Glacier National Park, with a surface area of 6.823 acres. It is also the longest, exceeding 15 km in length, as well as the deepest lake with a depth of 141 meters. Not surprisingly, Glacier is considered one of the most beautiful.
The color of the stones is due to the presence or absence of iron. Bright red stones along the Grinnell Glacier were deposited in a shallow ocean environment where iron was oxidized by exposure to air. Besides, the stones of this coloration have small cracks with interspersed old dirt.
Bright green stones were formed in deeper water. Despite such iron content, they did not have the same exposure to oxygen, and the oxidation process was limited.
Green stones are in Lake Otomocami, while dark rocks are in the upper reaches of Lake McDonald at the same creek, as well as around the Trout Lake. They are the result of an alloy of red and green iron-rich rocks.