Ninja is a steel looping roller coaster in the Studio Backlot section of the park long known as Six Flags St. Louis in Eureka, Missouri (rebranded Mid America Adventure in August 2026). Riders climb to just over 108 feet before diving into a course packed with a vertical loop, a sidewinder, and a double corkscrew across 2,430 feet of track.
The coaster has an unusual origin story: it was originally built as Scream Machine for the 1986 World’s Fair, Expo 86, in Vancouver, British Columbia, running there from May to October 1986. Arrow Dynamics began building the ride but went bankrupt mid-construction, and Dutch manufacturer Vekoma stepped in to finish it before it was relocated and reopened as Ninja on April 8, 1989.
Stats at a Glance
- Park: Mid America Adventure (formerly Six Flags St. Louis)
- Manufacturer: Vekoma (completed after Arrow Dynamics)
- Opened: April 8, 1989
- Height: about 108 feet
- Top speed: about 55 mph
- Length: 2,430 feet
- Inversions: 4
The Ride Experience
After an 80-foot first drop, Ninja’s two seven-car trains send riders through a vertical loop, a sidewinder element, a mid-course brake run, and a closing double corkscrew, packing four inversions into a two-minute circuit. Each train seats 28 riders, two across in seven rows.
In 2016, the park added a Samsung Gear VR option on Ninja, letting riders wear headsets for a 360-degree virtual reality overlay synced to the coaster’s movements, one of the earlier VR coaster experiments among U.S. parks.
From World’s Fair Attraction to Six Flags Staple
Few coasters can claim a World’s Fair pedigree. Ninja began life as Scream Machine at Expo 86 in Vancouver, where Arrow Dynamics started construction before the company’s financial troubles forced Vekoma to complete the ride. After the fair closed, the coaster was purchased, relocated to Missouri, and reopened under its current name in 1989, where it has run continuously in the decades since.
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Ninja Photo Archive: June 2002
These are original ThrillZing photos of Ninja taken at Six Flags St. Louis on June 29 and 30, 2002, restored and upscaled from the original camera files. They show the Vekoma looper in its black-track, red-train paint: the station, a train leaving above the entrance, and the lift hill and loop above the trees. All photos are free to reuse under a CC BY 4.0 license with credit to ThrillZing and a link to this page.
Rub-on sunscreen that fits in a pocket — reapply in the queue without greasy hands on the lap bar.
Folds into its own pocket. Pop it on when the storm rolls in and the rides reopen to short lines.
Keeps your phone strapped to you, not in a loose-article bin. Zip it before the lift hill and walk straight off the exit ramp.
Ninja FAQs
Who manufactured Ninja at Mid America Adventure?
Vekoma completed Ninja after Arrow Dynamics, which began construction, went bankrupt during the build.
How tall is Ninja and how many inversions does it have?
Ninja stands about 108 feet tall and features 4 inversions, including a vertical loop and a double corkscrew.
Was Ninja always at Mid America Adventure?
No. It originally operated as Scream Machine at Expo 86 in Vancouver in 1986 before being relocated and reopening as Ninja in Missouri on April 8, 1989.
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Photo: Original uploader was Hagerman at en.wikipedia / CC BY-SA 3.0, via Wikimedia Commons.