Unexplained Boom Heard in South Dakota And Surrounding States Remains a Mystery

Spearfish — The mystery of what caused Monday’s loud boom remains. Some theories have been refuted, while more mysterious references have appeared. Shortly before 2 p.m., the boom was heard throughout the Black Hills. Some people said it shook their homes or businesses, rattling windows, and scaring them in several instances. But the noise was heard in a much larger … Continue reading →