SANTA ROSA, Calif. — U.S. Army Corps of Engineers park rangers participated in defensive tactics training April 4, 2012. Most of the 16 million visitors who enjoy recreation sites within the Corps' South Pacific Division are peaceful, but tragic news stories about the killing of rangers, like National Park Service Ranger Margaret Anderson who was gunned down while on duty at Rainier National Park, serve as a solemn reminder that the work rangers do can be dangerous.