River King Mine Train is a classic Arrow Dynamics mine train coaster at Mid America Adventure in Eureka, Missouri. It opened on June 5, 1971, as one of the park’s original attractions, and it still holds the distinction of being the oldest operating permanent roller coaster in the state.
The ride has stayed in the same spot in Eureka through decades of change, including a 2026 rebrand that saw the park, long known as Six Flags St. Louis, become Mid America Adventure under new operator Enchanted Parks. It was originally built as one half of a matching pair of side-by-side mine train coasters; the second track was removed in 1988 and relocated to Dollywood as Thunder Express before eventually settling at Magic Springs in Arkansas, where it still runs today as Big Bad John.
Stats at a Glance
- Park: Mid America Adventure, Eureka, Missouri
- Manufacturer: Arrow Dynamics
- Opened: June 5, 1971
- Height: 32 ft
- Drop: 41 ft
- Top speed: 37 mph
- Length: about 2,500 ft
- Inversions: 0
The Ride Experience
True to its mine train roots, River King Mine Train winds five-car trains through low, twisting terrain-hugging track rather than towering drops or inversions. Riders sit two across in three rows per car, for a total of 30 guests per train, as the coaster snakes through wooded turns and small dips over roughly three minutes.
The ride still uses manually checked lap bars rather than an automated restraint system, a detail that harks back to its early-1970s Arrow Dynamics engineering and gives the experience an old-school amusement park feel that’s increasingly rare on modern coasters.
A Brief Detour as Rail Blazer
In 1984, the park retrofitted the ride with stand-up trains and renamed it Rail Blazer. After a rider died from a fall during the season, the park pulled the stand-up trains and restored the coaster’s original seated cars and River King Mine Train name for 1985, a configuration that has remained ever since, surviving the park’s 2026 transition from Mid America Adventure to Mid America Adventure.
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River King Mine Train Photo Archive: June 2002
These are original ThrillZing photos of the River King Mine Train taken at Six Flags St. Louis on June 30, 2002, restored and upscaled from the original camera files. They show the 1971 Arrow mine train: the rustic entrance sign and the trains winding through the mining-camp station and scenery. All photos are free to reuse under a CC BY 4.0 license with credit to ThrillZing and a link to this page.
River King Mine Train FAQs
Is River King Mine Train still open?
Yes, it continues to operate at Mid America Adventure (formerly Six Flags St. Louis) and remains the oldest permanent roller coaster in Missouri.
Who manufactured River King Mine Train?
It was built by Arrow Dynamics (Arrow Development), the same company known for pioneering the mine train coaster genre.
What happened to the coaster’s sister track?
The park originally had two identical mine train coasters side by side. The second track was sold in 1988 and now operates as Big Bad John at Magic Springs in Arkansas, after a stint at Dollywood as Thunder Express.
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Photo: Unknown / CC BY-SA 3.0, via Wikimedia Commons.