Statement of Significance (as of designation - November 5, 1961):
These sites are associated with the mid-19th century conflict about the water boundary between Vancouver Island, British Columbia, and the U.S. Oregon Territory. Events came to a head in 1859, when an American settler shot a British pig. Words were exchanged, armed forces of both sides faced off on San Juan Island, and the "Affair of the Pig" almost led to war. After skillful, if belated, negotiations, the two nations agreed to joint occupation, and for a dozen years both maintained armed forces at these two camps on San Juan Island. At last the 1871 Treaty of Washington provided for a peaceful settlement of this dispute and the settlement of the boundary between Canada and the United States for the first time in history.