RICHMOND, Va. — A scenic section of the James River where a utility wants to put a power line was added to a list of America’s Most Endangered Historic Places this week, a designation preservation groups hope will encourage the power company to change its plans.

A coalition of groups and others welcomed the designation by the National Trust for Historic Places and said it would increase awareness of the Dominion Virginia Power proposal. The state’s largest utility wants to put the line along part of the river some have said would mar the scenic approach to some of Virginia’s most historic attractions.

“I think it will raise the level of the debate to a national conversation because these are nationally important resources,” said Elizabeth S. Kostelny, executive director of Preservation Virginia. She was also hopeful it would encourage Dominion to relocate the transmission line farther down the James or to route the line under the river.

In a statement, Dominion said it had “thoroughly investigated all viable alternatives, and only our proposal solves all the problems in a timely manner associated with providing reliable power to the north Hampton Roads area.”

“Dominion is sensitive to historic and environmental concerns,” said Scot Hathaway, vice president of transmission for the utility. “We have recommended a route that is the least impactful and the most economical.”

Dominion is seeking approval of the state Corporation Commission to build two 500-kilovolt transmission lines from its switching station in Surry County to a new switching station in James City County.

The 8-mile transmission line would cross 4.1 miles over the river and entail as many as 17 towers. Four of the towers will rise to nearly 300 feet, with the others averaging about 160 feet.

The proposed transmission line is stirring opposition because it would span a section of the James near the state’s Historic Triangle — Jamestown, Williamsburg and Yorktown. Jamestown was the first permanent English settlement in North America.

That section of river has been a passage for Native Americans and includes the Capt. John Smith Chesapeake National Historic Trail, named after the intrepid Jamestown settler.

The trust called that section of the river “a portal into a remarkable chapter of American history.”

“It is still possible to stand along the James River and visualize the scene that greeted the English settlers at Jamestown,” said Stephanie Meeks, president of the National Trust.

The proposed power line is opposed by Colonial Williamsburg, the College of William & Mary, the Virginia Conservation Network and local preservation groups.

The National Trust included the James River among 11 of the Most Endangered Historic Places. Other entries included Houston’s Astrodome stadium, New York’s old Pan Am Worldport Terminal at Kennedy Airport and Montana’s one-room schoolhouses.

The trust said of the more than 240 sites that have been on the endangered list over its 26-year history, only a handful has been lost.

Visit www.preservation virginia.org.