DENVER (KDVR) — The fire burning since Thursday in Black Canyon of the Gunnison National Park is now at more than 3,500 acres and is still 0% contained, National Park Service officials said in a Sunday update.

Officials said 190 personnel are working on the South Rim Fire suspected to have been started by lightning strikes that has caused the national park to shut down and several Montrose County evacuations.

The fire on Saturday increased on the western flank and fire head and started establishing in the canyon itself, “causing fire to build in the bottom and run up to the rim, creating dangerous conditions,” officials said.

Officials said the Sunday plan was to limit the fire spreading toward communities and dam infrastructure by burning off tying into natural features like rock outcroppings, using bulldozers and digging direct fireline where possible.

Airtankers and other aviation assets will support the efforts with retardant to protect structures, and night crews will work to stop the fire from spreading onto private land.

Crews will be working in 80-degree weather with low 11-16% humidity, officials said.