State transportation officials say signs with a national suicide prevention hotline number have been posted at a bridge that spans the Snake River near Twin Falls.  A regional director for the Idaho Department of Health and Welfare in south-central Idaho proposed the signs more than a year ago as a way to dissuade people from using the Perrine Bridge to end their lives. The Idaho Transportation Department announced Monday that 18-inch signs placed at each bridge entrance read: "Need hope? Call 1-800-273-8255." Perrine Bridge, some 480 feet above the river, gets a lot of attention as one of the world's most-frequented BASE jump sites with more than 5,000 jumps annually. But the bridge has on occasion drawn people looking to use the long fall to end their lives.