Corkscrew, Steel roller coaster in Athol, Idaho

Corkscrew is a steel roller coaster at Silverwood Theme Park in Athol, Idaho, built by Arrow Development. Its track runs through white arched supports and dark blue rails, with a 70-foot chain lift, a camelback, and two consecutive corkscrews. A red and yellow train climbs the lift before the inversions.

The coaster debuted in 1975 at Knott's Berry Farm in California, marking a turning point in steel roller coaster design. It was relocated to its present location in Idaho after being purchased and moved to Silverwood Theme Park.

The roller coaster design by Ron Toomer revolutionized theme park engineering as the first modern steel coaster to turn riders upside down.

The lift hill reaches 70 feet (21 m). After dispatch the train drops into a short U-turn, climbs, then descends through a 90-degree banked turn, a camelback, a banked right turn and two consecutive corkscrews before the brake run. Riders are inverted twice in a row, so secure loose items before boarding.

The prototype was built on site at Arrow Dynamics in Mountain View, California, before the Knott's family bought it. In 1989 Knott's sold it to Silverwood for $250,000 to make room for Boomerang. Its lift hill is 70 feet (21 m) tall.