VIDEO: Crews are battling "The Bullet Fire," which has burned more than 4,000 acres north of Fountain Hills.
Tonto National Forest officials say there is a Very Large Airtanker, two Hotshot crews, one state crew, and six engines working to contain the blaze.
It has scorched 4,178 acres as of late Monday morning and is 50% contained, officials say.
The Sugar Loaf area has been evacuated due to the fire. The Lower Sycamore area is also shut down to the public.
SR 87 was closed in both directions for several hours Sunday evening into early Monday morning. Arizona Department of Transportation officials said Monday that both directions of travel had reopened. Southbound traffic is open at milepost 204, though one lane is still blocked, according to ADOT.
The cause of the fire has not yet been determined.