TRENTON, N.J.—A coalition of environmental groups filed a federal challenge on Monday seeking to block a new high-voltage power line that would run through parkland spanning Pennsylvania and New Jersey, on either side of the Delaware River.

The lawsuit, filed in Washington against the National Park Service, challenges the agency's recent approval of the Susquehanna-Roseland line, which is slated to run through 16 municipalities in northwestern Jersey, from Berwick, Pa., to Roseland. The roughly $1 billion project would raise the power lines' capacity from 230 kilovolts to 500 kilovolts and raise towers to as high as 190 feet tall.

Parties to the lawsuit say the project will have a negative environmental impact, ruining views at the Delaware Water Gap National Recreation Area and helping keep coal-fired plants open by enabling them to sell power to East Coast customers.

"This decision by the Park Service will permanently scar the landscape and degrade the visitor experience in some of the most visited national parks in the country," said Hannah Chang, an attorney with Earthjustice, a group representing a coalition of a dozen local, regional and national environmental groups along with the New Jersey-based Eastern Environmental Law Center.

The National Park Service said Monday it doesn't comment on pending litigation.

Utility officials have said the Susquehanna-Roseland line would double the capacity and the height of power lines. The project is necessary to avoid power problems that could result in brownouts or blackouts, according to the companies building the project, Public Service Electric and Gas Co. in New Jersey and PPL Electric Utilities in Pennsylvania.

PPL spokesman Paul Wirth said the company expected to intervene in the suit and fight it, calling the move "a last-minute attempt by special interest groups to block a critical upgrade to our nation's power grid."

The suit says it is seeking to overturn the National Park Service's approval of the transmission line through national park land "and to stop construction until the NPS complies with federal law."