La Brea Tar Pits

Breathe in for a moment. On a warm afternoon, the air here carries a faint smell of hot road, like a freshly paved street. Look down at the grass and you may see a dark, glossy patch where something black has pushed up through the soil. Small orange cones sometimes mark these spots. This is not a spill. This is the ground itself, slowly leaking. You are standing in the middle of Los Angeles, on top of one of the richest Ice Age fossil sites on Earth.

Here is a small joke the city carries in its name. In Spanish, la brea means the tar. So when people say the La Brea Tar Pits, they are really saying the the tar tar pits. The name dates back to the Spanish and Mexican ranch era, when this land was part of a property called Rancho La Brea. The tar was here long before anyone named it. And it is still rising today, as it has for tens of thousands of years.

What is this black substance, exactly? It is not quite tar in the industrial sense. It is natural asphalt, the heaviest part of crude oil. Deep underground, oil fields lie beneath this whole district. The oil pushes upward through cracks in the rock. As it reaches the surface, the lighter parts evaporate into the air. What remains is thick, sticky, and black. In cold weather it stiffens. In summer heat it softens and flows, and that is when the smell grows strongest.

Long before the city existed, Indigenous peoples of this region knew these seeps well. The Tongva, whose homeland covers much of the Los Angeles basin, and their Chumash neighbours to the north used asphalt as a practical tool. It sealed baskets so they could hold water. It waterproofed the seams of boats. It worked as a glue for fixing tools. So the first chapter of this place is not about fossils at all. It is about people who saw the tar as a useful gift from the ground.

Now walk toward the large pond near Wilshire Boulevard. This is the Lake Pit, and it is not a natural lake. It formed from an old asphalt mining operation that filled with rainwater. Watch the surface closely. You may see bubbles breaking slowly through the dark water. That is methane gas, rising from the oil deep below. At the eastern edge, life-size sculptures of mammoths stand in the water. One appears to be sinking, while the others watch from the shore.

That scene shows the central story of this site. Picture the landscape during the last Ice Age. A thin layer of water, leaves, or dust could cover a pool of asphalt. A large animal comes to drink or graze. It steps in, and the sticky asphalt holds its legs. It cannot pull free. The trapped animal calls out in distress. And that sound, or the smell of a weak animal, brings the predators running.

This is the first surprise most visitors miss. The tar pits worked as a predator trap. For every plant-eater caught, several hunters and scavengers arrived to feed. Many of them became stuck too. As a result, the fossil record here holds far more meat-eaters than plant-eaters. The most common large mammal found here is the dire wolf. Excavators have recovered the remains of thousands of individual wolves. Few places on Earth have given scientists so many of one ancient predator.

The other famous hunter is the saber-toothed cat, known to scientists as Smilodon. It had two long upper teeth shaped like curved blades. So many skulls have come out of these pits that Smilodon became the official state fossil of California. Alongside these cats and wolves, the excavations have found Columbian mammoths, giant ground sloths, ancient bison, camels, horses, and the American lion. Yes, lions and camels once walked across the place where you are standing now.

The second surprise is about the smallest things. Big skeletons attract the crowds, but the asphalt also preserved tiny remains. Insects, snails, seeds, pollen, and small bones of rodents and birds all survive here. Scientists sieve the sediment grain by grain to find them. These tiny fossils matter a great deal. They show what plants grew here, what the climate was like, and how the ecosystem changed as the Ice Age came to an end. The small finds help explain the big ones.

Human history appears here too, but only once. The pits have produced the partial skeleton of a woman who lived roughly ten thousand years ago. Researchers call her La Brea Woman. Her remains are the only human skeleton found at the site. Scientists still discuss exactly how she died and how she came to rest in the asphalt. She is a quiet reminder that people lived in this landscape alongside the last of the great Ice Age animals.

In the early twentieth century, the land belonged to the Hancock family, who worked oil here. Scientists began serious digging on the property, and the finds were extraordinary. In the 1920s, the family gave the land to Los Angeles County so the site could be protected and studied. That is why the green space around you is called Hancock Park. The museum building, with its sloping grassy roof and its frieze of Ice Age animals, opened in the 1970s.

The excavations are not finished. When workers dug foundations for a parking garage at the neighbouring art museum in the 2000s, they found another dense fossil deposit. Scientists packed the blocks of asphalt and sediment into large wooden crates. That effort became known as Project 23, after the number of crates. Researchers are still working through that material today. Inside the museum, a glass-walled laboratory lets you watch preparators clean fossils by hand. The work is slow and patient, and it is happening right in front of you.

Before you leave, stand still for a minute near one of the seeps. Listen to the traffic on Wilshire Boulevard, and to the voices of children near the mammoths. Then look down at the dark, shining asphalt at your feet. It is still moving, still rising, still collecting leaves and insects as it has for tens of thousands of years. Somewhere beneath this lawn, there are bones no one has seen yet. As you walk away, watch where you step.