What continental US state has the longest north-south border?

California's north-south border is 800 miles, making it the state with the longest north-south border in the United States. The border is shared with Arizona and Nevada. Its coastline is 840 miles long, and it is the third largest state after Alaska and Texas. California has a wide range of geographical features, including Coastlines and mountains.

The longest north-south border of all U.S. states is Alaska's border with Canada, which is 1538 miles.