The department reminded residents to “keep in mind” essentials for pets and livestock, and to stay updated on the latest fire news.
“Emergency services cannot guarantee that they will be able to notify everyone if the situation rapidly worsens,” the department said.
“All material scientific observatory structures are still standing and there appears to be very little external damage at this time in terms of facilities on the Southwest Ridge, although many non-science buildings were lost,” Noirlab said.
According to InciWeb, the fire is burning in highly flammable grass and steep, rough terrain that is difficult to brush.
Inciweb says the fire started on a remote ridge of a mountain range on the Tohono O’odham Indian Reservation on June 11. It lists the cause as lightning.