WEST MIFFLIN — The group American Coaster Enthusiasts has named the Thunderbolt a Coaster Landmark, the third roller coaster to be so recognized at the Kennywood amusement park near Pittsburgh.

Kennywood is now the only park in the United States with three rides to be honored by the group, which was founded in 1978. The group has given the title to 30 coasters nationwide since 2002.

“The American Coaster Enthusiasts uses this designation to single out historically significant coasters, and there’s no doubt the Thunderbolt is significant to Kennywood, Western Pennsylvania and coasters in general,” Kennywood spokesman Jeff Filicko said.

Kennywood’s Jack Rabbit and Racer roller coasters were both designated landmarks by the group in 2010. All three are traditional roller coasters with wooden frames and tracks, though each has a signature feature.

The Thunderbolt grew out of a former roller coaster known as the Pippin. The Pippin was built in 1924 and was expanded and rebuilt to become the Thunderbolt in 1968. It’s unusual in that riders go down a steep drop immediately out of the station, which is possible because the coaster is built into the contours of a hillside.

“It’s a unique ride with a classic feel,” said Bill Linkenheimer, the group’s representative for Western Pennsylvania. The ride lasts one minute and 48 seconds and has a top speed of 55 mph with a 95-foot main drop.

The Jack Rabbit was built in 1920 and features a double-dip drop which pops riders up out of their seats, while the Racer, built in 1927, features two cars that race side by side. That coaster’s track is made up of two side-by-side, but continuous circuits, so that trains which begin on one side of the loading station finish on the other side, and vice versa.