One of Ulster County’s most popular tourist attractions is getting a climate-friendly makeover. This week, the Catskill Mountain Railroad announced that it would become the first tourist railroad in the nation to run entirely on biodiesel.

Established in 1982, the Catskill Mountain Railroad operates on 4.7 miles of the former Ulster & Delaware rail line between Kingston Plaza and the Hurley Flats. Over the past decade, ridership has grown dramatically, helped by holiday-themed excursions like the wildly popular “Polar Express.” Last year, ridership set records, topping 51,000, and the company was honored as the area’s “Best Tourist Attraction” by the Ulster County Regional Chamber of Commerce.

CMRR officials say the move to biodiesel will reduce greenhouse gas emissions by 74 percent, compared with regular diesel. The switchover will also reduce carbon monoxide and particulate emissions by nearly half, and hydrocarbon emissions by almost 70 percent.

Along with helping the tourist railroad meet its clean energy goals, the move to biodiesel will also help fuel the region’s expanding green economy. To facilitate the switch, CMRR has partnered with Newburgh-based startup NetZero Biofuels. The company makes thousands of gallons of biodiesel using a byproduct of soybean oil sourced from farms near Syracuse.

“With the CMRR being NetZero’s first major commercial customer, it is a win-win for both businesses by supporting a growing Hudson Valley supplier of green energy as well as making the Catskill Mountain Railroad a leader in sustainability in the U.S. railroad tourism industry,” railroad officials said in a statement Tuesday.