SUTHERLAND, Neb. (AP) — Preservation groups are discussing how to protect a portion of the Oregon-California Trail in Nebraska during construction of an electrical transmission line.

The proposed 220-mile (350-kilometer) long transmission project would pass through the trail’s rest stop in Sutherland.

The Nebraska Public Power District says the project is necessary to prevent power outages. But the Oregon-California Trails Association and the Nebraska State Historical Society say the line could threaten the remains of travelers who died on the trail.

The graves believed to be near the area haven’t been confirmed.

The power district is looking for ways to avoid disrupting natural habitats or areas of potential historical significance.

Spokesman Mark Becker says the district is considering alternate building techniques, including helicopters to pull the lines instead of taking them over land.