Grinnell Lake is located in Glacier National Park, in the U. S. state of Montana. Named after George Bird Grinnell, the lake has an opaque turquoise appearance from the rock flour which is transported to the lake from Grinnell Glacier. Grinnell Lake is accessible via the Grinnell Glacier Trail and is 3.2 miles from the Many Glacier Hotel. It lies below the north face of Angel Wing.