Two of three fires in Sequoia and Kings Canyon National Parks, which were sparked by a major lightning storm that passed through the area Thursday night, are growing and have prompted officials to close the entrance to Sequoia National Park.

Two of the fires have 0% containment and are in steep and dangerous terrain, according to the InciWeb.com national incident information system. The Colony Fire grew from four acres to 72 acres overnight, while the Paradise Fire has grown to 32 acres. Only the small, two-acre Cabin Fire is largely contained.

A news release from the two national parks said the fires “are growing and have the potential to affect park infrastructure and resources.” But the parks “are aggressively attacking these fires to suppress them.”

Because of the fires, parks officials closed Generals Highway between the entrance to Sequoia National Park and the Giant Forest Museum. At least one campground also was closed.

Hand crews are working on the ground to fight the fires, while multiple aircraft, including helicopters and air tankers, have been deployed to attack from the air.