(CNN) -- We can think of few things crazier than strapping a parachute to one's body and jumping off a bridge for a quick free fall.
The 450 BASE jumpers heading to West Virginia for this weekend's 35th annual Bridge Day might disagree.
On Saturday they're planning to jump off the 876-foot-tall New River Gorge Bridge, one of the world's longest steel single-span arch bridges, to prove it.
It's the only day all year that BASE jumpers -- whose acronym stands for these fixed points: building, antenna, span and earth -- can legally jump off the bridge. The jumpers carry parachutes designed to deploy quickly, softening their landings.
The bridge festival, billed as the largest extreme sports event in the world, is expected to attract nearly 100,000 people to Fayetteville.
About 450 BASE jumpers leaped off the bridge 903 times at last year's festival, and about 80,000 spectators packed the bridge and surrounding area to watch them.
For the second year, a smaller group of jumpers got to use a human catapult system in 2013 to get flung off the bridge.
Rappellers get the best views of the proceedings. They like to tackle the bridge challenge, slithering on ropes attached to the bridge from the catwalk underneath the to the gorge bottom, watching the parachutists go by.
Vendors surrounding the bridge will offer snacks, crafts and other ways to less strenuously celebrate the jumpers.