With more than 400,000 hectares of rugged, northwestern Montana wilderness to explore in the United States, a trip to Glacier National Park could fill up an entire summer and more. But let's just take one day and virtually visit Grinnell Lake. An 11-kilometre loop trail, a relatively easy one in this rugged country, takes you to the shores of the lake turned emerald-green by glacial silt. Grinnell Lake—as well as Mount Grinnell and Grinnell Glacier—is named for the naturalist George Bird Grinnell. For two decades, he lobbied for the creation of the park, and on May 11, 1910, the 'Crown of the Continent,' as Grinnell dubbed this area, became America’s 10th national park.