During the winter months, the lake’s level is dropped about 10 feet. This is near its pre-dam natural level. The lower water level enables better management of the rapid spring mountain melt-off. Here is a short time-lapse—filmed from the dock of good friends—of a Flathead Lake spring evening.
BTW, the two waterfowl that make brief appearances are loons.
You can watch this full screen and increase its resolution to 1080p HD
(the two icons in the lower right hand corner).