The San Miguel Power Association is tentatively proposing to close U.S. Highway 550 over Red Mountain Pass the first two weeks of May so it can finish clearing trees and other vegetation around its power line, a timeline that would allow the highway to reopen in time for Memorial Day weekend.

In an email last week to elected and appointed officials in Ouray and San Juan counties and other stakeholders, SMPA spokesman Alex Shelley said the rural electric cooperative is looking at closing a 2 1/2-m...