The Great Diamond Hunt continues with bridges

It is because of two massive granite outcroppings formed millennia ago that Yuma exists today. The granite, located on the riverfront near the Yuma Territorial Prison, marks the immensely important Yuma Crossing.

The outcroppings were first found by ancient tribes. Then in the 1500s, Spanish explorers were searching for gold in the area when they also discovered the crossing.

American explorers first came to the area in about 1826. By the 1850s, the California Gold Rush was in full swing, and tens of thousands of '49ers were traversing the river at the Yuma Crossing.

Due to the high amount of traffic, the American military saw a need to survey the area and later established a permanent presence.

To supply the forts in the region, the U.S. Army set up the Quartermaster Depot, which was supplied by steamboats.

The crossing was also very important to the railroad in Arizona. On Sept. 30, 1877, the Southern Pacific 4-4-0 No. 31 became the first locomotive to cross the Colorado River.

With the arrival of the railroad and the building of several dams on the river, the steamboat business was no longer viable and ceased to exist.

The next form of transportation to come to the area was the automobile, which created a need for a new bridge.

According to the Arizona Department of Transportation, in 1913, after years of prodding by Yuma citizens, Arizona Rep. Carl Hayden piloted a bill through Congress authorizing construction of a steel highway bridge over the Colorado River at Yuma. It would become known as the Ocean-to-Ocean Bridge.

The bridge would form a crucial link on the Old Spanish Trail Highway, which spans the country from the old Spanish colonial towns of St. Augustine, Fla., on the Atlantic coast to San Diego on the Pacific.

The Yuma bridge was funded in part by the Office of Indian Affairs to help facilitate transportation between the Quechan Reservation and Arizona.

The state of Arizona contributed $25,000, which was matched by Imperial County.

OIA engineers in Washington designed the long-span truss bridge and located it at the foot of Prison Hill Road, near the territorial penitentiary and immediately upstream from the existing ferry.

The bridge trusses would be carried high over the river by concrete abutments and piers.

In June 1914, the OIA contracted with the Omaha Structural Steel Works of Nebraska to fabricate and construct the bridge for $73,800. But the OIA engineers were unfamiliar with the deceptive nature of the Colorado River and problems soon arose after construction began in September.

After portions of the construction were washed away twice in the winter months, Omaha Steel decided to erect the trusses on barges and float them into position.

On March 3, 1915, the 336-foot span was swung into place during a carefully choreographed maneuver. On May 22, the bridge was opened to traffic with great ceremony and celebration in Yuma.

Then in 1916, after a devastating flood heavily damaged a railroad bridge near the crossing, the Southern Pacific Railroad began planning a 400-foot-long through pin truss bridge that would also be built next to the Ocean-to-Ocean Bridge.

Initially, a foreman and 10 men with pickaxes began excavation for the pier on the California side on April 26,1923. The last of the concrete for the California pier was poured on Oct. 10.

On the Arizona side, excavation was accomplished with large dump buckets handled by a derrick, and the concrete work was finished within two weeks after the completion of the California piers.

The erection of the falsework to support the bridge during its construction began on Oct. 5. Two pontoons, 40 feet long and 8 feet wide, were lashed together. They supported a pile-driver while a 3,700-pound hammer drove the 75-foot long piles into the riverbed.

As there initially were no railroad tracks to the construction site at the time, the structural steel for the bridge had to be hauled in using other means.

The first steel was set in place on Oct. 22. Eight days later the structural steel was in place from pier to pier. The last pin was driven into the bridge at 9:30 p.m. on Nov. 11, 1923.

It then took three weeks to apply three coats of paint to the 2,144,224-pound superstructure.

The installation of the decking was completed on Feb. 28, 1924, and the bridge was ready for a single track that led to a double track at each end of the bridge.

A new passenger station was built, and the Pacific Fruit Express ice deck for icing refrigerator cars was relocated to a new freight yard. The new line formally opened on April 1, 1926.

Today the Yuma Crossing is as important as ever because the Ocean-to-Ocean Bridge, the railroad bridge, the 4th Avenue Bridge and the Interstate 8 overpass continue to carry travelers and freight safely across the river.

Chris McDaniel can be reached at cmcdaniel@yumasun.com or 539-6849.