December 19, 2018

On Dec. 21, 1928, 90 years ago this Friday, United States President  Calvin Coolidge signed the Boulder Canyon Project Act that authorized the building of the Hoover Dam. The dam, which was named for Coolidge’s successor as president, Herbert Hoover, is one of the highest concrete dams in the world. It stands in the Black Canyon of the Colorado River on the Arizona-Nevada border. The Boulder Canyon Project included the construction of a hydroelectric power plant, a reservoir, and later the Mike O’Callaghan-Pat Tillman Memorial Bridge. The Boulder Canyon Project supplies water and electric power for much of the Pacific Southwest.

The Boulder Canyon Project Act of 1928 authorized the construction of Hoover Dam, one of the world’s highest concrete dams. The Mike O’Callaghan-Pat Tillman Memorial Bridge spans the canyon just south of the dam. Credit: U.S. Department of Transportation

Hoover Dam stands about 25 miles (40 kilometers) southeast of Las Vegas, Nevada. Hundreds of thousands of people visit the dam each year. The dam is 726 feet (221 meters) high and 1,244 feet (379 meters) long. Elevators descend the equivalent of 44 stories into the dam. But they still do not reach its base. The concrete base is 660 feet (200 meters) thick. It contains enough concrete to pave a two-lane highway from New York City to San Francisco. Water falling through the huge turbines of the dam generates electric power. The power is sold to industries and to cities in the Pacific Southwest. The power plant has a capacity of about 2 million kilowatts.

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The Boulder Canyon Project Act of 1928 authorized the building of the Hoover Dam. The first page of the act is shown here. Credit: National Archives

Lake Mead, the dam reservoir, is one of the world’s largest artificially created bodies of water. It is about 115 miles (185 kilometers) long and 589 feet (180 meters) deep. The reservoir stores approximately 28 million acre-feet (35 billion cubic meters) of water. Water from Lake Mead can irrigate about 1 million acres (400,000 hectares) of farmland in the three-state area. The reservoir also supplies water for cities in southern California.

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This map shows the location of Lake Mead, a large artificial lake on the Arizona-Nevada border. The lake was created by the completion of Hoover Dam on the Colorado River. Credit: WORLD BOOK map

The need for a dam on the Colorado River was apparent in the early 1900′s. Floods were causing much damage in the Palo Verde Valley and in the Imperial Valley. Extensive levees were built. But crops died when the river ran too low to meet the area’s irrigation needs. In 1928, Congress approved the Boulder Canyon Project. The Bureau of Reclamation designed the dam and supervised its construction. The entire project cost about $385 million. The dam itself cost about $165 million. Hoover Dam was completed in 1935.

October 2, 2017

Last night, on October 1, in Las Vegas, Nevada, a gunman killed at least 58 people at an open-air concert near the Mandalay Bay Resort and Casino. The gunman fired from the window of his hotel room on the 32nd floor of the Mandalay Bay, shooting into a crowd of 22,000 people attending a music festival across the street. Armed with numerous automatic weapons, the gunman poured hundreds of bullets into the crowd until police reached his hotel room. The gunman then committed suicide. The attack—which has also resulted in over 500 injuries—is the deadliest mass shooting in United States history. The death toll from the domestic terror attack will most likely rise.

People run for cover as a gunman fires into a crowd attending the Route 91 Harvest country music festival in Las Vegas, Nevada, on Oct. 1, 2017. Fifty-eight people died in the domestic terror attack. Credit: © David Becker, Getty Images

The attack began just after 10 p.m. local time, not long after country music star Jason Aldean had taken the stage at the Route 91 Harvest music festival, a three-day event held in an open-air venue across the Las Vegas Strip from the Mandalay Bay. The Las Vegas Strip, a portion of Las Vegas Boulevard, is famous for its large resort hotels and casinos. Many people in the concert crowd did not react immediately to the attack, as the popping of gunshots was confused with the sound of firecrackers and drowned out by the music being played on stage.

People soon realized the horror of what was taking place, however, and began running for cover and searching for loved ones in the chaos. The shooting paused occasionally as the gunman reloaded his automatic weapons, but the rapid fire then resumed as bullets ricocheted around the concrete concert ground and inflicted further injuries. Police responding to the attack saw gun flashes coming from the Mandalay Bay, and soon zeroed in on the gunman’s locked hotel room. As police used explosives to burst into the room, the gunman shot and killed himself.

Thus far, the shooter, identified as 64-year-old Stephen Paddock, has not been tied with any militant or terrorist groups, and his motive remains unclear. Paddock lived in Mesquite, a small city northeast of Las Vegas. His dead body was found with 23 guns, many of which are readily available in Nevada, a state with some of the least stringent gun laws in the United States. Police found another 19 guns at Paddock’s home in Mesquite.

The previous worst U.S. mass shooting occurred just last year, in June 2016, when a gunman killed 49 people at a gay nightclub in Orlando, Florida. That shooter, who was killed by police, had professed his allegiance to an Islamic terrorist group.

January 12, 2017

On Dec. 28, 2016, President Barack Obama created two new large protected areas in the southwestern United States: the Bears Ears National Monument in southeastern Utah and Gold Butte National Monument in southern Nevada. To do so, the president used the executive power provided by the 1906 Antiquities Act. The act, meant to stop looting and destruction at prehistoric American Indian sites, gives the president the power to establish national monuments on federal land. Obama’s December actions protected some 2,500 square miles (6,475 square kilometers) of fragile and important desert landscapes, adding to his legacy of environmental protection.

Bears Ears National Monument in southeastern Utah protects one of the most significant cultural landscapes in the United States, an area with thousands of archaeological sites and other areas of beauty and importance. Credit: Bureau of Land Management

Bears Ears National Monument contains numerous sites considered sacred by Native American groups. The monument protects ancient petroglyphs (rock carvings), cliffside dwellings, and lands traditionally used by Navajo and other native groups to forage for wild plants used for food and herbal remedies. The protected lands will remain open for livestock grazing. The monument is to be administered by the Bureau of Land Management (BLM) and the U.S. Forest Service, in conjunction with an association representing native groups.

Gold Butte National Monument protects a beautiful and culturally significant desert landscape northeast of Las Vegas, Nevada. Credit: Bureau of Land Management

Gold Butte National Monument in southern Nevada contains striking rock formations, forests of Joshua trees, ancient Native American sites, rare fossils, and a number of ecologically sensitive areas. The monument, known to many as “Nevada’s Piece of the Grand Canyon,” will continue to allow such recreational activities as hunting and fishing.

Conservationists, Native American groups, and many others applauded the president’s actions. Opponents of the monument designations included state legislators and county leaders who preferred the lands be used for mineral and fossil fuel exploration.

Theodore Roosevelt was the first president to use the Antiquities Act when he protected Wyoming’s Devils Tower in 1906. In 1908, Roosevelt also set aside 1,250 square miles (3,200 square kilometers) in Arizona’s Grand Canyon, creating a forerunner of the popular national park. Since taking office in 2009, Obama has used the Antiquities Act more than any other president, establishing or expanding more than two dozen new national monuments.

Throughout Obama’s presidency, his administration has taken numerous steps to combat global climate change, promote energy efficiency, and create or extend protections in areas of scenic, historic, and ecological importance.