Americans wondering whether a nearby dam could be dangerous can look up the condition and hazard ratings of tens of thousands of dams nationwide using an online database run by the federal government.
But they won't find the condition of Hoover Dam, which impounds one the nation's largest reservoirs on the border of Nevada and Arizona. Nor is there any condition listed for California's Oroville Dam, the country's tallest, which underwent a $1 billion makeover after its spillway failed.
