Big Thunder Mountain Railroad at Walt Disney World's Magic Kingdom is on track to roar back into service in early May after more than a year behind construction walls, and the revamped ride could welcome some younger thrillseekers. The overhaul brings new scenes, retracked rails, and refreshed trains that lean into the attraction's frontier story while adding updated visual effects.
What's new inside the mountain
Disney has shared the first details of a new underground sequence called the Rainbow Caverns, a glowing chamber filled with phosphorescent pools and shimmering stalactites and stalagmites that Disney says will deepen the attraction's storyline, according to the Disney Parks Blog. The post describes the work as a "mountain-top to cavern-deep" refurbishment designed to preserve the ride's legacy while adding fresh show elements.
Track work and new trains
Photos and reporting from theme-park outlets show crews replacing long stretches of track, rebuilding rockwork, and installing new lift-hill segments throughout 2025. WDW News Today documented new track on the lift hill and scaffolding around multiple sections of the attraction during spring 2025 construction.
Who can ride: the height question
Disney's official attraction page still lists Big Thunder's minimum height at 40 inches, while reporting from MLive says the refreshed attraction will reopen on May 3 and drop the minimum to 38 inches. The Disney attraction page notes the ride will reopen with a little bit of new magic in Spring 2026, but has not posted an updated height chart at the time of publication.
What this means for families
A two-inch reduction would line Big Thunder up with attractions such as Seven Dwarfs Mine Train (38 inches), potentially letting more preschool-aged guests ride with an adult and easing the need for Rider Switch for some families. Disney's official Disney World height requirements page lists current minimums and remains the best resource for planning until Disney confirms any change.
Quick timeline
The mountain closed for the refurbishment in early January 2025, and crews have been retracking and testing sections throughout the year, while Disney has repeatedly signaled the attraction would return in spring 2026. On-the-ground coverage and construction permits tracked progress in 2025, and reporting now places the reopening in early May, a timeline that will be confirmed when Disney updates its official pages.
Takeaway
If Disney confirms the 38-inch minimum and a May 3 reopening, more little riders would be able to try one of Magic Kingdom's classic mountains during the resort's late-spring rush. first covered the original refurbishment announcement in 2024; check Disney's attraction page for the final word before you book.
