FARMINGTON — State and local officials could build a bypass road for the endangered Whittier Road, which has been threatened by bank erosion along the Sandy River.

The Maine Army National Guard told officials Tuesday during a meeting that it might be able to help with a bypass to serve local traffic.

The ground between the road and the river has been eroding steadily since August 2011, when Tropical Storm Irene caused a 50-foot-wide, 300-foot-long section of the riverbank to collapse into the water.

The Guard might be able to help the town by building a bypass running behind the houses that face the Sandy River, Town Manager Richard Davis said. In order to move forward with such a proposal, the town would have to get easements over the land of two property owners on the road.

Davis said the Guard is exploring the idea but has not committed to it.

“It has to be a meaningful training opportunity for them, and they have to have the funding available,” he said.

Davis said he didn’t know what the total cost of the project would be or how the town and the Guard would split it.

If the bypass is approved, it will be a temporary measure designed to serve local traffic and the six residents who live on the threatened section of the road. Davis said the quality would be “like a camp road” and would not be designed to handle school buses or oil delivery trucks, which are now avoiding the road.

The town has been seeking federal assistance to fund a $277,170 bank stabilization project as a permanent solution, but the Federal Emergency Management Agency has withheld approval based on concern about the project’s potential effect on the endangered Atlantic salmon, which uses the Sandy River as a critical spawning habitat.

A biological assessment of the stabilization project’s effect on salmon population would cost the town $21,615, but Davis said 75 percent of the cost probably would be reimbursed by the federal agency if and when the project is approved.

Because of concerns about the salmon’s spawning season, the stabilization project cannot begin until next July. Town officials have said they expect the road to collapse by then.

The meeting to discuss the bypass was arranged by Joanne Mooney of the Maine Emergency Management Agency, and was attended by Maj. Scott Lewis from the Maine Army National Guard; Rick Jones, the town’s environmental consultant; Tim Hardy, the Franklin County Emergency Management Director; and members of the local Board of Selectmen.