The Pima County Board of Supervisors passed a resolution opposing plans for a portion of Interstate 11 to run through Avra Valley near Tucson.
Earlier this month, Gov. Katie Hobbs said she would not direct the Arizona Department of Transportation to scrap the proposed path, despite a lawsuit opposing it.
Pima County Supervisor Rex Scott says construction could destroy delicate desert ecosystems.
"All the different environmentally sensitive areas, county, state and federal properties that would be impacted by taking the Avra Valley Route," Scott said.
Most of the board supported an alternative route that would run the highway parallel to Interstate 10.
