Photo: The Canadian Press. All rights reserved.

Yoko Ono, left, and her son Sean Lennon visit a fracking site in Franklin Forks, Pa., Thursday, Jan. 17, 2013. They are on a bus tour of natural-gas drilling sites in northeastern Pennsylvania and plan to visit with residents who say they've been harmed by the controversial extraction process known as fracking.(AP Photo/Richard Drew)

Yoko Ono, Sean Lennon and Susan Sarandon are touring gas drilling sites in northeastern Pennsylvania.

The celebrities boarded a tour bus in New York City on Thursday morning and headed to rural Susquehanna County.

They're looking at gas wells, compressor stations and other evidence of the Marcellus Shale drilling boom. They're also talking to residents who say they've been negatively impacted by the industry.

Ono and Lennon formed a group called "Artists Against Fracking" to oppose drilling in New York, where they own a farm upstate. Local anti-drilling activists are leading Thursday's tour in Pennsylvania, where thousands of wells have been drilled and hydraulically fractured in recent years.

Ono says, "It's going to be a disaster for New York state."

An industry spokesman calls the tour a charade.