A loyal and trustworthy tour bus at Piston Peak for 72 years, Ol’ Jammer knows every trail, stream, rock, and tree. This strong and seasoned bus with a gentle soul is eager to share his vast knowledge of the park’s history with the multitude of admiring daily visitors.
Ol' Jammer first appears during the party at the Grand Fusel Lodge, telling the Secretary of the Interior that the deer population is steady and the number of red-propped balsa thrush has increased in a healthy state while being called a "bumper kisser" by Cad.
Later, Jammer, along with Pulaski, attempt to convince Cad Spinner to cancel the unveiling and evacuate the guests at the lodge, but Cad angrily refuses and insults both Pulaski and Jammer, with Jammer being called 'old with a dumb hat on'. When the tourists see the fire and start to panic, Jammer and the Secretary evacuate the cars, while Pulaski evacuates the planes.
Jammer, Pulaski, and the Secretary are seen at the main road exit, helping the tourists evacuate, when a tree catches on fire and falls on the exit, blocking it, with no other way out. Luckily, Windlifter, Dusty Crophopper, and Lil' Dipper drop their retardant on the fires, extinguishing them, while the Smokejumpers parachute out of Cabbie and remove the debris, allowing the tourists to proceed.
Five days later, Jammer and Pulaski arrive at the firefighters' base, with Jammer stating that Dusty had he and Pulaski worried and they are glad that Dusty is all right, however, Dusty is surprised to hear that Jammer is the park's new superintendent. Jammer hears the news about Dusty's gearbox. While Pulaski travels to Propwash Junction to attend the Corn Festival, Jammer stays in Piston Peak National Park and is not seen again for the last few minutes of the film.