California and Nevada
Kazakhstan and Russia share the second longest border at 6,846 km
The countries with the longest land border are Canada and the United States. They share a border that is approximately 8,891 kilometers (5,525 miles) long.
Idaho and Montana
Kansas and Oklahoma
Oregon and Washington
Montana and Wyoming
New Mexico and Texas
Nebraska and South Dakota
Virginia and West Virginia
Mexico Montana Alabama Wisconsin and Central Amercia
The border between Canada and The United States of America is one of the longest in the world. Until 9/11 it was the world's longest undefended border. ------------------------- Russia, Denmark, Norway, and the USA. We share a border with all of them.
No, Ontario has the longest border with Canada and the US.