Looking northeasterly, September 6, 1899: The removal of the temporary trestle and the rock below the temporary crossing of the Santa Fe Railroad in Section 8 near Lemont. This view is from the top of the wall near the Lemont Road Bridge looking northeasterly. (MWRD photo, disc 9, image 71)

The construction of the masonry wall on top of bedrock in Section 5, 1895. A steam powered derrick in the Main Channel is used to lift and place the rock. Another derrick on top of the slope in the left background is also used for wall construction. A large group of spectators has gathered to watch the masonry wall construction process. (MWRD photo, Geiger set, image 300)

The construction of a rubble masonry wall on top of bedrock in Section 4, September 1894. A single leg derrick is used to lift and place each masonry stone. The masonry courses were set back at vertical intervals to emulate the steps created by the channeling machines in solid bedrock. (MWRD photo, disc 4126, image 88)

Another gantry-type piece of equipment for masonry wall construction, Section 4, July 7, 1896. This equipment allowed for workers to set masonry stones at multiple levels as it travelled along the face of the wall. The horse in the foreground probably belongs to an SDC engineer or inspector, or possibly a supervisor for the Section 4 contractor. (MWRD photo, disc 2, image 65)

Construction of concrete wall in Section 14, September 4, 1896. Cast-in-place concrete wall was used in this area due to the poor quality of bedrock and lack of a sufficient quantity of masonry stone. (MWRD photo, disc 2, image 90)

September 3, 1895, Section 10 at the Cook-Will County Line. Tablet Day, a celebration of the completion of excavation of rock in this and nearby sections. A large group of spectators has gathered to witness the placing of the granite tablet near the top of the northwest wall. (MWRD photo, Geiger set, image 327)

September 6, 1899, Section 10. The granite tablet as it appeared before filling of the Main Channel with water. When filled with water, the tablet is visible above the normal water level. (MWRD photo, disc 9, image 62)

View from the Willow Springs Road Bridge looking northerly on May 5, 1899. A crowd of spectators looks at the transition of the Main Channel from the vertical wall rectangular Rock Section to the sloping wall trapezoidal Earth and Rock Section. (MWRD photo, disc 12, image 12)

This view from the Willow Springs Road Bridge looking northeasterly on July 20, 1897, shows the transition of the Main Channel from the vertical wall rectangular Rock Section for contract Section 1 in the foreground to the sloping wall trapezoidal Earth and Rock Section for contract Section A in the background. This transition was necessary because bedrock was no longer prevalent toward Chicago. (MWRD photo, disc 127, image 96)

The SDC pumping plant in Section 14, July 1896. Although the contractor for each section was responsible to maintain drainage of the excavation, this became burdensome for the contractors who finished early. The SDC assumed responsibility for drainage for the entire length of the Main Channel. The steam powered pumping plant was operated nearly to the end of 1899 when it was removed and the wall restored in time for filling of the channel in early 1900. (MWRD photo, disc 2, image 66)

Looking north from the terminal wall of Section 15, November 12, 1896: The gradual enlargement of the Main Channel for a turning basin in the foreground and construction of the Lockport Controlling Works sluice gates on the left. The bedrock was lower and walls were built to contain the water in the Main Channel. The water, if not contained, would flow over the landscape. (MWRD photo, disc 10, image 61)

The fabricated sluice gates before installation in the guides on the inside face of each pier on the right, November 12, 1896. This view shows the downstream face of the gates. The upstream face is a flat plate. The area where the gates are standing would become the beginning of the tailrace channel leading to the Des Plaines River. (MWRD photo, disc 10, image 62)

The construction of the Lockport Controlling Works sluice gate piers with the vertical gate guides, September 4, 1896. The Main Channel is to the right. (MWRD photo, disc 2, image 89)

July 7, 1897. Work is nearly complete on the Lockport Controlling Works sluice gates to the right, and excavation of the foundation for the Bear Trap Dam to the left. The view is from the Main Channel terminal wall looking northwesterly. (MWRD photo, disc 4126, image 64)

The completed sluice gate structure to the right and construction of the foundation of the Bear Trap Dam in the foreground, September 15, 1898. The Main Channel is to the right. (MWRD photo, disc 5, image 68)

The installation of the upstream (right) and downstream (left) leaves of the Bear Trap Dam, February 7, 1899. The downstream leaf is mounted on a fixed hinge along the downstream edge. The two leaves are hinged at their junction. Water will flow over the top of the leaves and by raising the leaves, the rate of flow will be diminished. (MWRD photo, disc 7, image 101)

Details of the downstream leaf of the Bear Trap Dam, February 7, 1899. The holes in the foundation allow flow to enter or exit the chamber providing buoyancy to reduce the dead weight of the leaves and to facilitate raising or lowering the dam. (MWRD photo, disc 8, image 3)

The completed leaves and the installation of the hoists at each end of the Bear Trap Dam, April 28, 1899. (MWRD photo, disc 5, image 11)

An inspection group on top of the 160-foot long Bear Trap Dam, May 5, 1899. (MWRD photo, disc 12, image 8)

The completed Bear Trap Dam in the center and the seven sluice gates in the right background, June 30, 1899. Without water in the Main Channel, the sluice gates and dam could not be tested. (MWRD photo, disc 9, image 11)

April 29, 1899. The left half of a two-photograph panorama of the Lockport Controlling Works. This view shows the Bear Trap Dam in the center and the first three sluice gates on the right. On the left and foreground are the walls of the end of Section 15 of the Main Channel. (MWRD photo, disc 12, image 5)

April 29, 1899, the same day as Photo 5.44. The right half of a two-photograph panorama of the Lockport Controlling Works. This view shows six of the seven sluice gates and the eight bulk-headed sluice gate bays. (MWRD photo, disc 12, image 4)