Sovereignty of islands that cross US/Canada border?

Question

How is the sovereignty of islands that cross the Canada/US border determined? Does the border go through some islands, or are they all one side or the other?

Answer 1

The United States and Canada have reached agreements on the sovereignty of every island near our shared maritime borders with the exception of one island between Maine and New Brunswick the name of which escapes me at the moment. At present the future sovereignty over this island is under protracted negotiations at the IJC or International Joint Commission which has been tasked with solving border disputes between our two nations for almost a century now.

In the past however, our two nations (and the British Imperial Authorities that proceeded our current state) have resorted to all variety of diplomatic (and military) means to determine sovereignty. For example, in Puget Sound the British and the Americans had agreed in the 1847 Oregon Boundary settlement that the maritime border would follow the largest contiguous passage between the San Juan/Gulf Islands but for the next twenty years never managed to agree just which passage that was exactly. To solve this, they invited the German Kaiser (Emperor) to determine what he felt was the largest channel and his decision constitutes that border to this day. In the case of the Great Lakes and St. Lawrence, those islands were all divied up by British and American diplomats trying to keep the peace in North America in the decade after the War of 1812. In the case of Alaska panhandle, well that border dispute was never over any islands. What the young Dominion was trying to do there was control parts of the mainland over which people heading to the Klondike gold fields were passing. That too was settled by diplomats.

Hope this answered you question thoroughly and didn't bore you to tears.

Answer 2

the only island I think has a border line on it is Smuggler Island in the St Lawrence River, and that is just because the bridge to the other island is so close they took enough land off the edge of the larger island to make a customs post. All other islands have the border routed around them so they belong to the US or to Canada, not shared.

Answer 3

the border is only on the mainland. It does not extend out to sea, because then Alaska would be part of Canada, which it's not. I think all islands would belong to one or the other.