Final answer:
North Dakota is the state that features both Lake Sakakawea, the state's largest man-made lake and the third largest in the U.S., and Lake Oahe, which extends into South Dakota.
Step-by-step explanation:
The state that is home to both Lake Sakakawea, which is the largest man-made lake in the state and the third largest in the U.S., as well as Lake Oahe, is North Dakota. Lake Sakakawea is located on the Missouri River, just as is Lake Oahe, although Lake Oahe also extends into South Dakota. These artificial lakes were created by damming rivers, a common practice to generate electricity, provide water for irrigation, and control floods. Their presence in North Dakota is a significant geographic and cultural feature, as the Missouri River has been historically important for the Great Sioux Nation and indigenous peoples of the area.