Black Canyon

A view of the Colorado River flowing through Black (not Boulder) Canyon.

2024-05-21

Nutrients in the nation's waters : too much of a good thing?

Includes bibliographical references (p. 22)

1996-05-21
2004-10-27
2004-10-04

Outlet works -- Hoover Dam

Shows water spewing from the outlet works of Hoover Dam. Sun is shining through the water

Hoover Dam interior

Color transparency of the interior of Hoover Dam showing the giant generators. A man standing next to a generator gives perspective as to its size.

Construction on the Arizona power house

Construction on the Arizona power house. A portion of the dam face is seen in the upper left. A construction worker stands on a dump truck in front of the power house and another worker is seen sitting on part of a cableway in the lower center of...

1935-03-26

Close-up of construction on the central section of the power house

Close-up of construction on the central section and a portion of the Nevada side of the power house, directly below the dam face. Concrete pouring forms and other construction equipment are seen around the structures.

1935-05-27

Construction on the Nevada valve house seen from the Arizona side of the Hoover Dam...

View from the Arizona side of the Hoover Dam construction site of work on the Nevada valve house. Construction on the Nevada power house is seen in the lower right. Concrete pouring forms are visible on both structures. A temporary bridge is seen...

1935-06-24

Water outlets at Hoover Dam during construction

View of the outlet works spewing water. This photo was taken while the dam was still under construction and shows cables, construction equipment and workers.

Intake towers -- Hoover Dam

Close-up view of intake towers at Hoover Dam with the reservoir (Lake Mead) behind them.

Construction on the Nevada power house

View of construction on the Nevada power house from the downstream cofferdam. Concrete pouring forms and steel framework stand on top of the power house foundation. The dam face can be seen in the upper right. Temporary buildings, construction...

1935-01-28

View of Hoover Dam from the Nevada side, showing the dam, the intake towers, spillways,...

View of Hoover Dam upon completion, taken from the Nevada side of the Colorado River in Black Canyon. Visible are the dam face, the four intake towers, the two spillways and various roadways in the canyon and on top of the dam face.

1935-09-27

View of power house from above -- Hoover Dam site

Shows the power house and valve houses in a photo taken from the top of Hoover Dam. Buildings and concrete pouring forms are visible.

1935-08-26

Looking upstream toward the upper plug and raise, in diversion tunnel no. 3.

View through diversion tunnel no. 3 showing concrete plug poured to close the tunnel. On the upper left another tunnel angles into the main tunnel. Mud and debris coat the tunnels.

1934-05-25

Hoover Dam under construction

View from the bottom of the canyon looking upstream at the dam and the power house. Trucks, lumber, and a cable spanning the canyon are visible. Pieces of lumber are piled around the site.

1935-10-28

Spillway and Hoover Dam during construction

Shows the Nevada spillway and the face of the dam in the background. Cars are visible on the road across the top of the dam. Some of the intake towers are also visible. Construction equipment, buildings, and roads are shown. The Colorado River...

1935-07-26

Construction inside tunnel, Hoover Dam site

Shows construction looking upstream in a tunnel at Hoover Dam. One of the pipe sections is in place. Scaffolding and other building materials are shown.

1935-11-25

View from the top of Hoover Dam during construction

View looking down from the top of Hoover Dam during construction. It shows the power houes, the valve houses and the lower cofferdam. Cars and trucks, buildings and structures, roads, and various equipment can be seen. A cable spans the canyon...

1935-02-25

Interior of valve house during Hoover Dam construction

Interior view of a a valve house under construction at Hoover Dam. An emergency gate is being installed. Construction materials are lying on the floor.

1935-08-27

Hoover Dam valve house under construction

Shows the Arizona valve house being built. Construction equipment, buildings, cables and high scaling equipment are visible on the side of the canyon.

1935-04-25

Third millionth cubic yard of concrete being lowered to Boulder Dam

A concrete pouring bucket lowers the third millionth yard of concrete used in the construction of Hoover Dam. Cableways, the intake towers under construction, mountains, and construction workers are also visible.

1934-12-05

Central section of the powerhouse

Shows the floor level of the powerhouse under construction. The number 2 adit car is in the extreme background. Construction workers are also visible.

1934-10-30

View of Lake Mead and reservoir area

View of Lake Mead and the reservoir area amid the surrounding mountains.

1935-03-04

Hoover Dam during construction, from the Nevada side

Shows the dam from the Nevada side. The completed road, parapets, and intake towers are visible. One of the spillways can be seen in the background. There are trucks and people on the new road.

1935-06-01

Hoover Dam during construction

View of Hoover Dam during construction, showing the power houses. Various buildings and structures are visible as well as concrete forms and hoisting machinery. There is a cable stretched across the canyon.

1935-07-25

View of Hoover Dam during construction

View of Hoover Dam construction site with the intake towers and Colorado River visible above. The power houses are under construction at the base of the dam. A cable spans the canyon and several construction buidngs are shown. There is high...

1934-11-02