Question: when did the first railroad cross the western sierra madre
[{'answer': '1880s', 'provenance': [{'wikipedia_id': '1152361', 'title': 'Sierra Madre Occidental', 'start_paragraph_id': 81, 'start_character': 43, 'end_paragraph_id': 81, 'end_character': 48, 'bleu_score': 1.0, 'section': 'Section::::People and history.:Mexican Sierra Madre.:19th century.\n'}]}, {'provenance': [{'wikipedia_id': '1152361', 'title': 'Sierra Madre Occidental', 'start_paragraph_id': 81, 'start_character': 0, 'end_paragraph_id': 81, 'end_character': 651, 'bleu_score': 0.9389250182346821, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1347609361733736532}, 'section': 'Section::::People and history.:Mexican Sierra Madre.:19th century.\n'}]}]