Question: what us state forms the western boundary of montana
[{'answer': 'Idaho', 'provenance': [{'wikipedia_id': '19978', 'title': 'Montana', 'start_paragraph_id': 2, 'start_character': 402, 'end_paragraph_id': 2, 'end_character': 407, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '19978', 'title': 'Montana', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 321, 'bleu_score': 0.9645876452711911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11901452343016009392}, 'section': 'Section::::Geography.\n'}]}, {'provenance': [{'wikipedia_id': '19978', 'title': 'Montana', 'section': 'Section::::Abstract.', 'start_paragraph_id': 2, 'end_paragraph_id': 2, 'meta': {'evidence_span': ['Montana is bordered by Idaho to the west, Wyoming to the south, North Dakota and South Dakota to the east, and the Canadian provinces of British Columbia, Alberta, and Saskatchewan to the north.', 'Montana is bordered by Idaho to the west, Wyoming to the south, North Dakota and South Dakota to the east, and the Canadian provinces of British Columbia, Alberta, and Saskatchewan to the north.', 'Montana is bordered by Idaho to the west, Wyoming to the south, North Dakota and South Dakota to the east, and the Canadian provinces of British Columbia, Alberta, and Saskatchewan to the north.']}}]}, {'provenance': [{'wikipedia_id': '19978', 'title': 'Montana', 'section': 'Section::::Geography.\n', 'start_paragraph_id': 8, 'end_paragraph_id': 8, 'meta': {'evidence_span': ['Wyoming is to the south, Idaho is to the west and southwest, and three Canadian provinces, British Columbia, Alberta, and Saskatchewan, are to the north.', 'Wyoming is to the south, Idaho is to the west and southwest, and three Canadian provinces, British Columbia, Alberta, and Saskatchewan, are to the north.', 'Montana is one of the nine Mountain States, located in the north of the region known as the Western United States. It borders North Dakota and South Dakota to the east. Wyoming is to the south, Idaho is to the west and southwest, and three Canadian provinces, British Columbia, Alberta, and Saskatchewan, are to the north.']}}]}]