Big Thunder Mountain Railroad Roars Back to Life at Magic Kingdom After 16 months behind construction walls, Big Thunder Mountain Railroad reopened at Magic Kingdom on May 3rd, and the return was everything fans hoped for, plus one thing nobody expected. Disney Parks Blog confirmed the reopening with a detailed look at what the refurbishment delivered. The work went deep: a full track replacement, refreshed passenger trains, and updated ride systems designed Post navigation Big Thunder Mountain Returns and Disney Dreams Even Bigger The Muppets Are Almost Ready to Rock Hollywood Studios