Hetch Hetchy Railroad

Construction of O'Shaughnessy Dam

With the passage of the Raker Act in 1913, San Francisco began to plan to tap the Tuolumne River watershed for water and power. A key element of the plan was a new reservoir in the Hetch Hetchy Valley, but access to the area was poor, so a railroad was planned. The first 9 miles (14 km) were completed in 1915, and the remaining 59 miles (95 km) were completed by October 1917. Construction costs for the HHRR were about US$3 million, far less than what the city might have paid contractors to transport concrete and other materials for the dam over the rough terrain.

Hetch Hetchy Railroad operated as a common carrier from July 1918 to February 1925 while the dam was under construction. As a common carrier it was subject to rules of the California Railroad Commission, so there are published time tables and tariffs for this period. However, unlike most common carriers, the president of the railroad was San Francisco Mayor James Rolph, and the vice president and general manager was the construction project's chief engineer Michael O'Shaughnessy. Revenue to support operation of the railroad was generated by charging timber companies and others along the line for freight. The line also carried mail for those in the area.

Since the support of the public in San Francisco was essential to the remote construction project's success, excursion trains were run to the site. For about US$30, passengers would board a sleeper car in San Francisco on Friday night, crossing California's Central Valley overnight, then boarding Hetch Hetchy line excursion cars on Saturday morning. Tourists spent two days viewing the construction site and the surrounding forest, spending Saturday night in bunkhouses and eating meals prepared on site. On Sunday afternoon they boarded the train for the trip back down the mountain, met the sleeper cars for the Sunday night valley crossing, and arrived back in San Francisco on Monday morning in time to go to work.

Raising the O'Shaughnessy Dam

Intensive operations supporting the construction of the dam were complete in 1923, but the rail line continued operating as a freight and mail hauler, especially in winter when roads were too muddy for freight or were snowbound.

Between 1934 and 1938 the line was pressed back into construction service while the height of the dam was increased from 364 feet (111 m) to the present 430 feet (130 m) above bedrock. Since repairs were necessary before the line could again haul heavy freight to support construction hauling, and it was the height of the Great Depression, an Emergency Relief Act provided about 600 workers to refurbish the line. Operations of the restored line were turned over to the Sierra Railroad, and the reconstituted railroad started operations May 13, 1935, with a train of four cars powered by Sierra engines #30 and #32.

Decline and deconstruction

The amount of freight that remained to be hauled after construction activity ceased in 1938 was not sufficient to continue using steam engines; gasoline locomotives were used instead. Rain washouts and difficulties clearing heavy snowfalls made winter operations very difficult. The station at Hetch Hetchy Junction was removed in 1938. Sidings and spurs were ripped up and the steel sold to support the war effort in the early 1940s, and structures in Groveland were removed in 1944. Roads into the area improved, and with low usage the railroad tracks deteriorated. In 1949, the entire line was dismantled.

An abandoned HHRR bridge across the Tuolumne River was removed between 1967 and 1971 to clear the canyon for the expansion of Lake Don Pedro.

Several parts of the railroad's right-of-way were used for roadbeds: State Highway 120 in Big Oak Flat, and Cherry Lake Road to Camp Mather and beyond to the O'Shaughnessy Dam.