About the Flathead Basin

Headwaters of the Columbia River, the Flathead Basin comprises 6 million acres of lush forests, productive agricultural lands, and vibrant towns. The three forks of the Flathead River, which have the Wild and Scenic River designation, flow into Flathead Lake, the largest natural freshwater lake west of the Mississippi. The Flathead Basin serves a critical ecological role, providing habitat to important native species, such as grizzly bears and westslope cutthroat trout.

While Flathead Lake is considered to be oligotrophic (lacking in plant nutrients), decreases in water quality have led the U.S. Environmental Protection Agency and Montana Department of Environmental Quality to categorize it as “impaired” for nitrogen, mercury, phosphorus, and polychlorinated biphenyls (PCBs). Given the connectivity and nature of water, the activities in the Flathead Basin are of major interest to downstream states, tribes, and other partners.

As a result of the COVID-19 pandemic, the Flathead Basin experienced (and continues to experience) unprecedented growth as more and more people seek refuge from densely populated areas in the Montana wilderness. According to the U.S. Census Bureau, Flathead County added 3,681 people between July 1, 2020, and July 1, 2021. That’s a growth rate of 3.5%, making the Flathead area the fastest growing micropolitan region in the nation. As tourism and population rates in northwest Montana increase, the pristine waters and exquisite natural resources of the Flathead Basin are seeing unprecedented amounts of recreational use, growth, and development, making their protection and conservation even more urgent.

Flathead River Basin (Mobile loGIStics Mapping & Montana Lake Book)