<Tr> <Th> Locale </Th> <Td> Lake Mead National Recreation Area, Clark County, Nevada--Mohave County, Arizona </Td> </Tr> <Tr> <Th> Official name </Th> <Td> Mike O'Callaghan--Pat Tillman Memorial Bridge </Td> </Tr> <Tr> <Th> Other name (s) </Th> <Td> Hoover Dam Bypass Bridge </Td> </Tr> <Tr> <Th> Maintained by </Th> <Td> Arizona Department of Transportation (ADOT) Nevada Department of Transportation (NDOT) </Td> </Tr>

How did they build the bridge at hoover dam