BLY, ORE. -- Lower winds and better weather helped crews using bulldozers and helicopters battling the nation's largest wildfire in southern Oregon, but gusty winds pushed a Northern California wildfire into Nevada on Thursday, prompting evacuations as blazes burn across the West. Oregon's Bootleg Fire grew to 624 square miles (1,616 square kilometers) -- over half the size of Rhode Island. However, authorities said higher humidity Wednesday and overnight and better conditions allowed crews to improve fire lines. The fire also was approaching an area burned by a previous fire on its active southeastern flank, raising hopes that a lack of fuel could reduce its spread, and the forecast was for favorable firefighting weather again Thursday.