GRAND JUNCTION, COLO. (AP) -- Two water-dropping helicopters, two smokejumpers and a Hotshot crew are among resources now assigned to a wildfire that managers have been allowing to burn in the remote

Little Books Cliffs Wilderness Study Area north of Grand Junction.

Fire officials say they have largely let the fire burn because it was naturally sparked by lightning, isn't threatening structures and can benefit habitat by burning pinyon-juniper that has taken over former grasslands. But they said Tuesday they also will manage the flames to protect forage for the area's wild horse herd.

The fire was about 350 acres Tuesday. Officials say it could grow to 1,000 acres or more by this weekend.

Fire officials say there are oil and gas wells in the area, but they have been shut down.

(Copyright ©2011 by The Associated Press. All Rights Reserved.)