A wildfire burning near the US Arizona-Utah state line has now spread to 11,168 acres, authorities said, adding that the blaze would get extreme due to dry fuel, high heat and erratic winds.
The blaze, dubbed "Pine Hollow Fire", was caused by lightning on Wednesday night and then was fueled by dry grass, brush and woodland, InciWeb, an interstate incident information system, reported on its official website on Saturday.
It added that complex terrain and bad weather hampered efforts to contain the fire, reports Xinhua news agency.
Some 208 firefighters are battling the blaze, the report said.
So far there is no report of damage or injuries, while the fire was zero per cent contained.
The fire, burning about 1.6 km south of the Arizona-Utah state line, forced authorities to cut roads to the North Rim of Grand Canyon National Park, evacuated a campground nearby and requested tourists to suspend their trips to the area.
The recent spell of hot and dry weather in many US Western states have led to several active wildfires.