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How the La Brea Tar Pits Work

The History of the Tar Pits

Fossil fuels were used by human populations long before the Industrial Revolution, and that includes the asphalt found in the La Brea Tar Pits. For example, Native American tribes used asphalt from the pits to waterproof everything from canoes to baskets.

When the Spanish later occupied the area, they used the land for cattle ranching. It was eventually sold to the Hancock family in 1870, and they drilled for oil. A few studies and small-scale excavations followed, but it wasn't until after the turn of the century that things really started heating up. In 1913, the Natural History Museum of Los Angeles County (known by a slightly different name at the time) was granted access to the lands, and it initiated an intense two-year investigation that uncovered a large portion of the specimens in the collection today. Ninety-six pits were dug during the course of those excavations, but the working conditions were unsafe and the efforts were haphazard. For example, only bones belonging to larger animals received much attention, while smaller fossils, like those of plants and invertebrates, were often overlooked.

A man named L. E. Wyman led those first major excavations, but it was paleontologist Chester Stock of the California Institute of Technology who would do most of the early research work on the recovered remains. Some of the pits proved more bountiful and provocative than others, and some of the most captivating finds came from Pits 3, 4, 9, 61 and 67. But it was Pit 91 that proved to be the real star of the show over the years and has been excavated on and off ever since. More on that on the next page.