The Coconio County Sheriff's office said early Sunday that the fire hadn't damaged any homes or buildings.
The sounds of helicopters and air tankers buzzed overhead late Saturday as fire retardant and water were dropped on the blaze. Winds estimated at 35 mph earlier in the day that fueled flames as high as 10 feet had calmed at night and the flames dropped to 3 feet.
No structures have burned and no injuries have been reported. The fire broke out Saturday afternoon near the popular Little America Hotel and sent smoke through parts of the city and caused traffic to back up on Interstate 40, Flagstaff city spokeswoman Kimberly Ott said.
The blaze quickly worked its way up the hill and threatened homes in two neighborhoods while burning about 600 acres.
The hotel was briefly evacuated. Evacuation orders for 170 homes remained in place Sunday morning, fire spokeswoman Karen Malis-Clark said. Several hundred other homes were are on standby to be evacuated.
About 16 families have checked into a temporary shelter at a middle school, American Red Cross spokeswoman Kelli Young said. Sixty animals from the Coconino Humane Society were moved to another shelter north of town.
Authorities questioned a man who started a campfire in the area where the fire is believed to have been started. There was no evidence tying the man to the fire, but police said they haven't ruled him out.