Sierra Sidewinder

By the mid-2000s, Mack Rides had developed a spinning-coaster format that let each individual car rotate freely based on rider weight distribution and track forces, rather than the motor-controlled spin systems used on rides like Vekoma's Mad House-style coasters. Knott's announced Sierra Sidewinder in late 2006 as the format's addition to the area near Camp Snoopy.

The finished ride sends free-spinning cars through 1,400 feet of track, including a vertical loop, at up to 37 mph — because the cars rotate independently based on how they're loaded and how riders shift their weight, no two rides play out exactly the same way, even on repeat rides in the same car.

Sierra Sidewinder opened May 26, 2007, giving Knott's a compact thrill coaster positioned as a mid-intensity option between the park's family rides and its larger inverted and launch coasters.

For years afterward, it remained the only Mack Rides free-spinning coaster installed anywhere in the United States, a distinction that made it a frequent stop for touring coaster enthusiasts specifically because of its manufacturer and mechanism rather than its size.