"The start of the graveyard shift went unnoticed on the bridge. Ton upon ton of rock went over the side and hours passed, but still the pace was maintained, one truck dumping every fifteen seconds. The gray light of dawn revealed that the pool upstream from the barrier was turbid and swollen, boiling just a few feet beneath the planks of the bridge and rising rapidly toward the mouth of tunnel Number 4. [Finally] a boisterous, frothing tongue of water raced down from the crest and plunged toward the dark tunnel inlet. In an instant, the small embankment melted under the watery onslaught and with a long, bubbling sigh the Colorado gave up its struggle... and poured into the smooth concrete channel that had been laid for it. "58 Joseph E. Stevens "Once the water was being bypassed over that site, people came to worship in a way. People couldn't help but make the pilgrimage to this wonderful technological achievement. Hell, the country's out of control, the economy's out of control, but we 're controlling the Colorado River."59 - Guy Louis Rocha Hours after Hoover left the dam site, one hundred idling trucks loaded with broken rock lined up along the road leading to the bridge near the upstream portals of the diversion tunnels. All day and night, the trucks dumped their loads, finally turning the Colorado out of its ancestral bed at about 7:30 a.m. on November 14, 1932. Rerouting the Colorado represented the first major step in building the dam, but the riverbed next must be de-watered, excavated through tons of silt down to bedrock, and protected from the Colorado's notorious spring floods. One and one-half miles of the riverbed crawled with crews as work began on two massive cofferdams to bracket the site where the dam would eventually stand.