If you’re a savvy traveler to Grand Canyon National Park, you know that the best way to arrive at the South Rim is by train. Yes, you could drive, but it’s much more fun to park your car in Williams, Ariz., and ride the historic Grand Canyon Railway for two and a half hours across the Colorado Plateau to the edge of the canyon.But did you know you have French fry oil to thank for powering some of those trips?Indeed, on 16 scheduled runs throughout 2016, you can board a train pulled by a majestic 1923 steam engine that was converted by the railroad to operate on recycled vegetable oil to reduce carbon emissions. No wonder this quirky steam train smells a bit like French fries.The steam engine conversion, inspired by innovations of carmakers, was quite an engineering feat, as the railroad’s stable of historic iron horses had been put out to pasture due to environmental concerns about pollution. Not only did the conversion work, but it worked so well that the then-90-year-old steam engine No. 4960 galloped along virtually carbon-neutral, releasing fewer emissions than the diesel engines used to pull the train on other days. In another nod to conservation, the water in the boilers contains reclaimed rain and snowmeltJust how many batches of fries and deep-fried shrimp does it take to power the 65-mile journey each way between Williams and the South Rim? You don’t measure that in miles per gallon, according to the Railway. It’s more like gallons per mile, but plenty of waste vegetable oil is available from restaurants in Phoenix, Williams and at the South Rim.So, there’s very little dark colored smoke belching from Locomotive No. 4960, the French fry train. But engine operators can throw some sand into the boiler to give photographers the iconic picture of smoke streaming from the stack.Recycled waste vegetable oil is just one way the Grand Canyon Railway helps protect the environment. The fuel-efficient diesel engines, which pull modern domed and rebuilt parlor cars, use ultra-low sulfur diesel fuel and reduce traffic and its attendant pollution into the National Park by as many as 70,000 cars a year.The rail line, which opened in 1901 primarily to haul freight and minerals, had been lost to financial failure in the 1960s, when travelers abandoned trains to drive their own cars. The train was resurrected in the late 1980s and now transports as many as 700 passengers each day between historic depots in Williams and at the South Rim of the Grand Canyon. Each depot was built more than 100 years ago.Travelers may return to Williams on the same day—the train remains at the Grand Canyon for about three hours between trips—or book lodgings at the South Rim and stay overnight. (Packages feature lodgings inside the park and in Williams, as well as breakfasts, dinners and guided tours. Book them at thetrain.com/offers-packages.)From Williams, the journey through Grand Canyon Country begins in a Ponderosa pine forest, gently drops to a wide-open prairie of sagebrush and grama grass, then climbs to the piñion pine forests at about 7,000 feet for the approach to the National Park. Passengers watch for elk, mountain lions, mule deer, and a variety of birds, from bald eagles to horned owls, ravens to California condors.Bringing the life of the Old West alive, trip highlights begin with a Wild West shootout at the 1908 Williams Depot prior to each morning’s departure. Additional Wild West entertainment and live action aboard the train features an attempted daily train rob by the Cataract Creek Gang, justice being restored by Marshal Will B. Justice, strolling musicians who roam the train, and even the Cataract Creek Gang on horseback.Trips aboard the steam engine train depart from Williams Depot at 9:30 a.m. and arrive at the South Rim at 11:45 a.m. The train departs Grand Canyon Depot at 3:30 p.m., returning to the Williams Depot at 5:45 p.m. The trip lasts 2 hours and 15 minutes each way. The train operates every day but Christmas and New Year’s.For more information, visit thetrain.com or call 800-THE-TRAIN (843-8724).For more travel experiences available from Xanterra Parks & Resorts and its affiliated properties, visit Xanterra.com/explore.