Verizon Wireless is planning to raise its communication tower in Vineyard Haven from 77 to about 130 feet in order to clear a number of trees that it says will eventually grow into a line of sight between the tower and the mainland.

The tower currently handles all land line service for the Island via narrow-width microwave, including for police, fire and EMT departments, and 911 service. It also provides internet access and reroutes service from Nantucket.

“A single large tree could be an impediment in this particular case,” said Linda Sibley, a member of the Martha’s Vineyard Commission, which is reviewing the project as a development of regional impact (DRI). But she also questioned whether the trees (identified as white pines) would in fact grow that tall.

Property owners north of the tower on the Edgartown-Vineyard Haven Road have refused to allow Verizon to trim the trees, leading to the proposal to extend the tower instead. The tower was raised from about 60 feet to its current height in 1987.

“The idea is to get it up out of the way of any potential trees once and for all,” Island attorney Geoghan Coogan, representing Verizon, told the Gazette after a preliminary meeting with the commission land use planning committee on Monday.

According to a commission report, some of the trees are on public property and have been designated as shade trees by the town tree warden. Removing those trees would require a separate hearing at the town level.

Material submitted to the commission shows three trees entering the line of sight. Neither Mr. Coogan nor Mrs. Sibley could say how many trees of concern there were in all.

Mr. Coogan said the trees are only about 50 feet tall, but if they reach 100 feet they would interrupt service across the Island.

Mrs. Sibley said the new proposal has raised several questions.

“We did challenge them slightly about their assertion about how tall the trees were going to get,” she said. “The tallest ones in the United States are like 150 to 200 feet tall, so we are a little skeptical.” She also questioned whether Verizon had accurately identified the trees, and why the company would plan so far ahead. “Who knows if they are going to be doing microwave technology to the mainland in 20 years,” she said.

Tim Boland, executive director of Polly Hill Arboretum in West Tisbury, said white pines on the Island generally top out at around 50 or 60 feet, with their crowns spreading out as a result of high winds. “I have not found many above 60 feet,” he said in an email, adding that it would be unlikely for one to reach 100 feet on the Island.

Photographs of the tower appear to show an osprey nest, or its remains, atop the highest dish. Asked about the nest, Mr. Coogan said Verizon would take steps to mitigate the effects of the extended tower. “They would do whatever is necessary there environmentally,” he said. “How they’d do that, I’m not sure.”

As part of the project, three existing microwave dishes would be moved farther up the tower, with the lowest moving from 55 to 95 feet, and a new eight-foot dish would be added at an elevation of 125 feet.

The project heads to the full commission for a public hearing on Sept. 7.