McDonald Creek Overlook is a small lot and a platform above a narrow rock channel, where spring melt runs hard enough to shake the deck. The upper creek is the best-known breeding water in the lower 48 for harlequin ducks, small sea ducks that come inland each May.
Coming up on your left, across the oncoming lane, McDonald Creek Overlook. Pull in if you want to feel a platform shake, and if you do, turn left to carry on. In spring the melt comes down this valley and funnels through narrow rock walls so hard that the viewing platform vibrates under your boots. In November of two thousand six, warm rain on early snow sent a flood through that pounded the railings. Stay behind those rails. The rocks are slick and the water is very cold. Now give the fast water a long look, because this creek holds something rare. No creek in the lower forty-eight has a higher density of breeding harlequin ducks, and a quarter of all the chicks born in Montana are raised on this water. A harlequin is a small sea duck, the only North American duck built for fast water. They winter on the Pacific coast, and in May the male follows the female inland to the very stream where she was born. Once she's laid her five or six eggs, he leaves for the coast, and she raises the chicks alone, in a nest within about three feet of rushing water, where a single flood can take everything. Red Grinnell rock comes next, near Avalanche Creek. This road crosses eight different rock formations in all, and you can read them by color through your window. Red means that old sea floor met the air. Green means it never did.
Photo: NPS / Glacier National Park · Public domain