A wildfire northwest of Ontario has grown to about 2,000 acres and prompted a Level One 'Be Ready' notice for nearby neighborhoods, according to local fire officials.The Butter Field Springs Fire is burning about two miles north west of the Ontario Rural Fire Protection District in the Moores Hollow area northeast of the freeway.Ontario Fire and Rescue said crews saw one structure briefly threatened east of the fire along Grove Road. Officials also confirmed that the Bureau of Land Management is serving as incident command.The level one notice has been requested for the Moore's Hollow area surrounding the fire, signaling residents should be aware of potential changes and stay prepared in case conditions worsen.Interstate 84 westbound, which was closed earlier in the day due to the fire, has since reopened.Crews remain on scene working containment lines as the fire continues to burn in dry conditions.This is a developing situation. We will continue to update this article as more information becomes available. ...read more read less