The hummocky highlands that straddle the border between the U.S. state of North Dakota and the Canadian province of Manitoba are called the Turtle Mountains. They are modest-sized for mountains, part of a plateau that rises just 600 to 800 feet (180 to 240 meters) above the surrounding plains.
However, the increased elevation results in an additional 10 inches (25 centimeters) of precipitation per year, enough to support hardwood forests rather than grasslands. (A process called the orographic effect enhances precipitation at higher elevations when topography forces passing air upward and causes water vapor to cool and condense into clouds.)
The forests stand out in this snowy view of the plateau, captured by the MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Terra satellite on January 3, 2025. Forests cover about half of the plateau, appearing darker than the surrounding snow-covered wetlands, farmland, and grasslands. Trembling aspen, bur oak, balsam poplar, and green ash dominate, providing habitat for a variety of animals including fox, weasel, badger, deer, marten, and moose.
Stagnant glaciers sculpted the plateau’s many kettle lakes and prairie potholes during the last ice age. As debris-covered blocks of ice slowly melted, they left the surface pockmarked with small depressions. The resulting wetlands cover about a quarter of the plateau and support populations of turtles, frogs, salamanders, several types of fish, waterfowl, and other aquatic birds.
Wildlands cover much of the plateau, but signs of human activity are visible as well. About a quarter of the area has been cleared and converted to farmland, which appears as bright snow-covered areas in its center and southwest. About 5,000 people live on the Turtle Mountain Reservation, home to a band of Chippewa, on the southeastern part of the plateau near Belcourt.
The rectangular borders of the densely forested Turtle Mountain Provincial Park in Manitoba are also visible in the northern third of the plateau. In the winter, the park has become a destination for cross-country skiing, ice fishing, snowmobiling, and sledding—at least for the cold-tolerant. Chilly weather prevailed when MODIS acquired the image. Temperatures averaged minus 6.7 degrees Fahrenheit (minus 21.5 degrees Celsius) at the nearby Devils Lake Regional Airport Station on January 3, according to Weather Undeground.
NASA Earth Observatory image by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Adam Voiland.
