Black, gold, gray, red
Muir is an old steam locomotive who works at the Piston Peak National Park.
Planes: Fire & Rescue
He is predominantly black, gold and gray, and sports red wheels arranged in a 2-6-0 wheel arrangement. He has his name on the sides of his cab, the number 21 on his dome and smokebox, and the words "Piston Peak Railways" on his tender.
- Unlike the steam train seen in Planes, Muir's mouth is on the front of his steam motor instead of his cowcatcher.