TELLURIDE – They've traveled from New York City to Huntsville, Ala.; from Houston, Tex., to Monterey, Calif. And they're doing it with grease.

Telluriders got an eyeful Monday as they walked along Colorado Ave., while the Big Green Bus was parked outside American National Bank. The environmentally retrofitted vehicle is transporting 15 Dartmouth University students around the country this summer as they educate Americans about energy issues, and meet with policymakers, from their vehicle that operates on waste vegetable oil.

The Big Green Bus is part of an initiative started five years ago by a group of Dartmouth Ultimate Frisbee players who wanted to travel across the country “on the cheap,” according to Telluride High School 2007 graduate Grayson Zulauf, a Big Green Bus rider (and member of the Dartmouth Class of 2012).

Very quickly, the founding students realized that the bus provided a great platform for discussion of energy issues and climate change, and a tradition was born.

Today the Big Green Bus has grown both in popularity – 80 students applied for the 15 spots on this summer's bus – and in technique. This year’s bus – a retrofitted 1989 MCI Motorcoach – represents a significant upgrade over the small school bus used in past years.

“It's really nice and new,” Zulauf says. “Things haven't been breaking.”

Along with a snazzy exterior paint job designed by crewmember Kari Cholnoky, the Big Green Bus features four brand-new SunPower 315 solar panels, a sustainably harvested bamboo floor and a LCD flat-screen television that uses 57 percent less energy than a standard CRT screen. Not to mention the vegetable oil-purifying grease filters in the bus' engine, which has powered the students all over the country.

As the Big Green Bus filled up on waste vegetable oil (from la Cocina de Luz) Monday, its riders set up an information table on the sidewalk documenting the vehicle’s mission and its journey so far, and suggested ways in which bystanders could improve their own energy efficiency.

The 15 crewmembers include artists, engineers – indispensable whenever the bus breaks down – and biologists, who all have an interest in environmental issues.

To prepare for the trip students read books ranging from Natural Capitalism to Thomas Friedman's Hot, Flat and Crowded. They learned how to give presentations and talked to past years' crewmembers. This has helped the Big Green Bus handle some tough crowds, like a group of Dartmouth alumni in Charleston, S.C., some of whom accused the students of being anti-globalization and too extreme in their message.

But there were good times, too – according to Zulauf, those included speaking with congressmen in Washington, D.C., and visiting Agricenter International, in Memphis, Tenn. The highlights, he adds, helped students feel they really are making a difference, especially with a range of media attention from NBC to Treehugger.com.

And at least ten people contacted Bus riders to say the suggested home audits saved 20 percent on their electricity bills.

While the Big Green Bus is largely a product of its riders’ dedication, it also runs on the hospitality and help from supporters. The crewmembers, who don't sleep on the bus, have relied on family, friends and Dartmouth alumni for food and shelter in most of the cities they've visited. Ninety percent of the trip's funding comes from corporate sponsorships, primarily Newman's Own and Waste Management.

But while they're touting environmental initiatives, the 15 students are enjoying each other's company as well.

“It's a cohesive group,” Zulauf says. “There hasn't been a lot of drama.”

They've visited National Parks and gone river-rafting. While in Telluride, a few even hiked part of the Sneffels Highline Trail.

Zulauf says that the values he learned growing up in Telluride – respect for the environment and leading an active lifestyle – have benefited him on the tour. But he adds that the town may not be as progressive as it seems; he says that despite the Telluride and Mountain Village mayoral challenge to rely only on renewable energy by 2020, he says he hasn't seen a top-down approach to change.

“There aren't many tangible things that I've seen done yet,” Zulauf says. “It's been more on an individual basis.”

The Big Green Bus is currently in Denver, and will move on to Omaha, Neb., from there. The tour ends back at Dartmouth in Hanover, N.H., on August 22. Crewmembers are also blogging about their experiences on www.thebiggreenbus.org/wordpress. For more information, visit www.thebiggreenbus.org