History Trapped in the La Brea Tar Pits

La Brea Tar Pits with Wilshire Boulevard in the background.

As you step outside Los Angeles County Museum the smell hits you. It’s an acrid odor as if a road crew were patching potholes on nearby Wilshire Boulevard. Minutes ago you viewed art by Picasso or Georges Braque. Now, as you walk toward the parking lot, you pass a dark, brackish bubbling lake where three fiberglass mastodons recreate the image of ancient beasts trapped in a lake of tar.

It’s called the La Brea Tar Pits, but it’s not really tar. It’s asphalt, the lowest grade of crude oil. The ooze has been seeping from the ground for thousands of years. As the asphalt dries, the lower density oil evaporates. What remains are blobs of icky, gooey, nasty black gook (aka “tar”).

The La Brea Tar Pits comprise the quirkiest tourist site in Los Angeles. They’re a perfect metaphor for the city, a spot where once dominant creatures became trapped and were left to die. Tens of thousands of years ago, the tar pits were covered with water, dirt and leaves. Mammoth elephants came by searching for sustenance. They became trapped in the tar and saber-toothed cats devoured the beasts. The cats became trapped as well and their bones were perfectly preserved.

In the 1800s, the Native American Chumash tribe used the tar to seal cracks on their wooden plank canoes. Early California settlers used the solidified asphalt to cover the roofs on their houses and to fuel campfires. In 1870, Henry Hancock of Union Oil Company acquired the area in an exploration for oil. (The area was later renamed Hancock Park.) In 1901, geologists found a fossilized ground sloth in the tar. They continued digging and discovered bones of saber-toothed cats, bison, tusked mastodons, giant millipedes, American lions and dire wolves. (Yes, Game of Thrones fans, dire wolves actually existed.)

In 1913, the Hancock family gave permission to the new LA County Museum to excavate the site for fossils. Since that time, over 100 pits have been excavated and more than 5.5 million fossils discovered. The preserved bones are dark brown from the petroleum and the oldest fossil is 50,000 years old. They were first put on public display in 1950 in the adjacent George C. Page Museum.

The tar pit lake is comprised of heavy sediment called “gilsonite” which seeps from the earth as oil. The lake is 23 feet deep and methane gas causes the surface to appear to boil. Surrounding structures are exposed to methane and escaping “tar” requires constant building maintenance to keep foundations intact. During the rainy season, the tar pits overflow and distribute toxic runoff into storm drains flowing toward the ocean.

The city designated a 400-block area around the tar pits as a high methane zone. In 1985, there was an explosion in a Ross Dress For Less retail store a few blocks from the tar pits. Fire burst through sidewalk cracks and tore buildings apart. The store was reduced to a heap of twisted metal. Locals thought there was an earthquake and 23 people were injured. Onlookers said the Ross parking lot looked like it was “raining fire.”

Methane gas pockets originate from crude oil deposits deep underground. Recently, the city re-routed the burgeoning LA subway line to avoid potential dangerous methane spots. The area boasts hundreds of shops, businesses and apartment buildings. Several museums share land with the tar pits. The offices of E Entertainment, the Hollywood Reporter, NBC and TV Guide are located across the street.

In 2006, while building an underground parking lot for LA County Museum, construction workers discovered 16 fossil deposits and a mammoth skeleton nicknamed “Zed.” The mammoth’s rear leg, vertebra and part of its skull were accidentally sheared off by construction equipment. The oldest known tar pit fossils are 50,000 years old. They were first put on public display in 1950 in the Page Museum. Birds, lizards and squirrels continue to get trapped and suffocate in the tar.

Movies like Volcano, Miracle Mile, Sin City and Last Action Hero featured the tar pits. In an episode of Laverne & Shirley, Squiggy rescues Lenny from the tar.

La Brea means “the tar” in Spanish. Thus, the La Brea Tar Pits translate to “The Tar Tar Pits.” Over the years, police have scoured the sulfurous lake for bodies and weapons. They’ve found shoes, paint buckets, license plates and wallets. Only one human fossil was ever discovered, the so-called La Brea Woman who died 10,000 years ago. She was estimated to be between 17–25 years old. She was found with the remains of a domestic dog.

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