BILLINGS, Mont. (AP) — Wildlife officials in the Northern Rockies want to sharpen their grizzly bear safety message after two hikers were fatally mauled over the summer in Yellowstone National Park.The Yellowstone region's grizzly population has expanded in recent years to about 600 bears. Those animals are pushing into new areas of Montana, Wyoming and Idaho — forcing wildlife agencies to broaden the public safety side of their "bear awareness" message.Also growing is the size of the crowd that message needs to reach: Yellowstone National Park last year hosted a record 3.6 million visitors.Chief Ranger Tim Reid says the park has done well instructing hikers who camp overnight about the dangers of traveling in bear country. He says the park has been less successful reaching day hikers such as the two mauling victims.___Online:Bear safety information: