The Museum fire north of Flagstaff had grown up to 1800 acres as of Monday night.
Authorities say about two dozen homes are under an evacuation order and thousands of people have been told to prepare to leave the area. They have been encouraged to pack supplies for three days.
A little rain fell at the fire scene Monday and weather forecasters say more rain is expected in the area later today, but there also could be some gusty winds and that could shift the direction of the blaze.
