Which symbol on the North Dakota flag represents the state's sky?

The blue background on the North Dakota flag symbolizes the state's sky. This choice reflects the significance of the sky in both natural and cultural contexts, embodying the expansive nature of North Dakota's landscape and the connection to the wide-open spaces that characterize the region. The color blue is often associated with tranquility and openness, enhancing the representation of the state's natural beauty.

The other symbols on the flag, while meaningful, do not specifically represent the sky. White stars are typically associated with unity and the states, while the yellow emblem often symbolizes the state's agriculture or heritage. The red stripes, though they add to the flag's visual appeal, primarily represent the state's Native American heritage and do not directly correlate to the sky.