Isa lake: The Two-Ocean Lake

The Isa Lake Viewpoint, located about 8 miles east of the Old Faithful Area along the Grand Loop Road in Yellowstone National Park, is not a terribly exciting place. On the way to the Old Faithful geyser, you can alight from your vehicle and stand on the edge of a thin sliver of water filled with waterlilies and fallen logs. By the side of the lake is a Continental Divide elevation sign, and an interpretive sign describing the significance of the Continental Divide and Isa Lake.

‘Continental divide’ is a geographical divide on a continent, often in the form of a mountain ridge, such that rivers and lakes on one side of the divide drain into one ocean or sea, and those on the other side … Read the rest