The term 'Neighbor of British Columbia' refers to two US states that border the Canadian province of British Columbia. These states are Yukon, which has five letters, and IDAHO, which also has five letters. Yukon is located in the northwest corner of Canada and borders Alaska, while IDAHO is located in the northwest corner of the United States and borders Montana, Wyoming, Oregon, and Washington. Both Yukon and IDAHO are neighbors of British Columbia, making them both part of the same region.