(UPDATE, 9:30 p.m.) The fire has burned an estimated 550 acres and is 0% percent contained, according to the Montana Department of Natural Resources & Conservation.
(UPDATE, 6:13 p.m.) Cascade County Sheriff Jesse Slaughter says that the Harris Mountain Fire is on both private and Bureau of Land Management land.
It is about 10 miles south of the town of Cascade on Sections 21 and 22, south of Upper Basin Road.
Sheriff Slaughter says that one residence has been evacuated, and pre-evacuation warnings have been given to several ranches in the area.
"It is roaring," said Sheriff Slaughter. "The heat, lack of humidity, and wind have really made that fire pick up out there."
The fire is throwing up a large column of smoke that can be seen for miles.
Helicopter crews are pulling water from the Missouri River near Sheep Creek for bucket drops to try and slow the fire's growth.
There are no reports of any injuries or damaged structures at this point.
Sheriff Slaughter gives a wildfire update:
(1st REPORT, 3:16 p.m.) A wildfire sparked on Friday east of I-15 between Cascade and Craig.
Initial estimates from emergency management personnel indicate the fire may have already burned about 300 acres.
At this point, there is no word on whether the fire is threatening any structures.
We have a reporter heading to the area, and will update you when we get more information.