The Hoover Dam is recognized as one of America’s modern marvels. The Federal Highway Administration named the gravity-arch dam one of America’s Top 10 Construction Achievements of the 20^th Century. Photographer Ansel Adams was fascinated by the structure, which took five years and 4.36 million cubic tons of concrete to complete. Countless artists have painted this stunning view, and about 7 million visitors line up each year to snap a selfie or Instagram picture.

The Black Canyon Raft Tour and Hoover Dam Postcard Tour offered by Black Canyon River Adventures takes guests down the Hoover Dam section of the Colorado River, through Black Canyon to the shores at Willow Beach. Here, travelers can glimpse rarely seen parts of the dam and the underside of the canyon’s newest bridge up close and personal. Our tour guides will regale you with facts and lore along your trip. In the meantime, here are a few extra tidbits about Hoover Dam to get you started:

1. The Hoover Dam was Blacklisted

Ok, the dam itself was never in trouble. Former President Herbert Hoover, however, had angered a good portion of the U.S. population by the time construction on the dam was underway. Hoover lost the 1932 election to Franklin Delano Roosevelt, who won by a landslide of 472 electoral votes to Hoover’s 59. So, on May 8, 1933, Secretary of the Interior Harold Ickes changed the structure’s moniker to “Boulder” Dam – after its original intended location at Boulder Canyon. Fourteen years later, Congress restored Hoover Dam’s name.

2. Many Gave Their Lives Here

More than a hundred workers died during the dam’s 5-year construction period. Reports said that 96 of these died during accidents on the jobsite. Another 42 workers supposedly died from illness – though historians point to carbon monoxide poisoning inside construction tunnels as the likely cause of these deaths.

3. The Dam Spawned a City

Las Vegas originally campaigned to host the slew of workers, managers, engineers, and authorities involved in the dam’s construction. According to Mental Floss magazine, Sin City’s underground clubs and houses of ill repute shuttered their doors when then-Secretary of the Interior Ray Lyman Wilbur paid the town a visit. The ruse failed and Boulder City was built to house the massive crew.

4. Fido Can’t Come Here

Except for registered service animals, pets aren’t allowed on the decks and bridge of Hoover Dam. For their safety, you can’t bring four-footed friends anywhere on site – not even in the official parking area on the Nevada side of the bridge. Leave Fido at home if you want to check out the dam tour or travel down the Colorado River by raft. The only furry friends here are the sheep, rabbits, and wild cats that make their home around Lake Mead and Black Canyon.

5.The New Bridge is a Whopper

The Mike O’Callaghan-Pat Tillman Memorial Bridge is America’s longest single-span concrete arch bridge, with 1900 feet of paved roadway spanning Black Canyon. It replaced the original Hoover Dam bridge in 2010 after officials banned commercial vehicles on the dam. The new bridge is about 175 feet taller its predecessor; the exact height of Dallas’ Renaissance Tower skyscraper (including spires).

More than 80 years after Hoover Dam was built, it still stands as a testament to modern engineering – and the thousands of people involved in its construction or daily operation. Book your Black Canyon River Adventure today and get an up-close, personal look at one of America’s top most impressive man-made structures.