In 1901, a Stanford graduate accidentally found mysterious bones in California. His discovery helped reveal a lost world of 600 ancient species

More than a century ago, William Warren Orcutt was looking beneath the California landscape with oil on his mind. Instead, the Stanford-trained geologist encountered something far older: bones preserved in sticky asphalt that belonged to animals from a world that had vanished thousands of years earlier. What followed helped bring scientific attention to what is now the famous La Brea Tar Pits in Los Angeles. The site would eventually yield millions of specimens and provide an extraordinary window into Ice Age California.

The Stanford Graduate Who Went Looking for Oil

Born in Minnesota in 1869, Orcutt moved to California with his family as a child. He later attended Stanford University, graduating in 1895 with a degree in geology and engineering. After working in surveying and engineering, he joined the Union Oil Company of California in 1899. Orcutt eventually became an important figure in California's developing petroleum industry, but it was his work around Los Angeles that produced his most unexpected legacy.

In 1901, while examining petroleum prospects around Rancho La Brea, Orcutt recognised that bones emerging from the area's asphalt deposits represented extinct animals. He hadn't technically discovered the first fossil there. Naturalist William Denton had described fossils from Rancho La Brea as early as 1875. However, that report attracted little attention, and bones encountered around the asphalt deposits were often assumed to belong to relatively recent animals. Orcutt's work helped scientists recognise just how significant the site really was.

Sabre Toothed Cats, Dire Wolves and Giant Sloths

Orcutt began collecting fossils with fellow scientist F.M. Anderson. The material was remarkable. According to Stanford Magazine, Orcutt assembled fossils that included remains of sabre-toothed cats, and his collection helped draw palaeontologists towards Rancho La Brea. The official La Brea Tar Pits history also records collections of sabre-toothed cats, dire wolves and ground sloths among the finds that demonstrated the site's importance.

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The breakthrough grew larger in 1905 when Anderson encountered a deposit containing an extraordinary concentration of bones and contacted University of California palaeontologist John C. Merriam. By 1906, Orcutt had amassed fossil material that he passed to Merriam, helping pave the way for more extensive scientific investigations.

Millions of Fossils Were Waiting Below

What began as scattered discoveries soon became a major palaeontological undertaking. Universities and scientific institutions conducted excavations during the early 20th century. In 1913, the Los Angeles County Museum began an intensive two-year excavation programme. Around one million fossil bones were recovered from 96 quarries or pits during that project alone. Stanford Magazine says subsequent work brought up millions of specimens representing around 600 species, ranging across mammals, reptiles and insects. The wider collections also preserve birds, plants and other organisms, allowing researchers to reconstruct far more than a collection of spectacular predators. The discoveries revealed an Ice Age Los Angeles populated by animals dramatically different from those walking its streets today.

How Did the Tar Pits Preserve So Much?

Despite their familiar name, the La Brea "tar" pits contain natural asphalt. For thousands of years, petroleum migrated towards the surface. Animals could become trapped in the sticky deposits, while predators and scavengers attracted to struggling animals could themselves become caught. Over long periods, their remains accumulated and were preserved. That process created an unusually rich record of prehistoric life beneath what eventually became one of America's largest cities.

An Accidental Discovery With a Lasting Legacy

Orcutt remained with Union Oil for decades and eventually rose to senior leadership. Yet his name also became permanently connected with palaeontology. A prehistoric La Brea coyote was even named in his honour. His story is also a reminder that the significance of a discovery is not always obvious at first sight. Fossil bones at Rancho La Brea had been noticed before Orcutt arrived.

What mattered was recognising what those bones represented and helping bring them to the attention of scientists who could investigate further. Orcutt went searching California's ground for petroleum. What he helped uncover instead was something far more unexpected: a vast archive of a lost ecosystem, preserved beneath Los Angeles for thousands of years.