The term 'Neighbor of B.C.' can be solved by the following crossword solutions: ALTA (4 letters), IDA (3 letters), ALB (3 letters), and WASH (4 letters). ALTA is the abbreviation for Alberta, a Canadian province located to the east of British Columbia. IDA is the abbreviation for Idaho, a US state located to the south of British Columbia. ALB is the abbreviation for Alberta, a US state located to the east of British Columbia. WASH is the abbreviation for Washington, a US state located to the south of British Columbia.