St. Mary's Lake

We arrived at the boat dock for the tour of St. Mary’s lake at 8:45 AM. Both the pilot and the on-board ranger were young women. I was impressed that the boat, an old wooden tour boat, runs on bio-diesel. It was so nice to ride in a power boat and not have to smell the exhaust. Makes me rethink my stink-pot hatred.

We learned that the reason the water in the lake is such a beautiful green color is that the glaciers cause erosion of the limestone and small particles enter the lake from the mountain streams. These limestone particles reflect back light and are responsible for the color. That’s why parts of the lake are greener than others; they’re closer to the source of glacial water.