After 31 years, I returned today to the LaBrea Tar Pits and George C. Page Museum both iconic tourist destinations in the Los Angeles area.  Why do I remember it was 31 years ago so vividly?  Because the last time I went there was on a  field trip in Mrs. Sanford;s fourth grade elementary class.  At the time I didn’t appreciate the rich history and geological significance I just knew it was a day we didn’t have to go to school!

Today was typical Los Angeles weather, 80 and sunny, and perfect day for a stroll through Hancock Park which houses the George C. Page Museum and La Brea Tar Pits.

The La Brea Tar Pits (or Rancho La Brea Tar Pits) are a famous cluster of tar pits around which Hancock Park was formed, in the urban heart of Los Angeles. Asphalt or tar (brea in Spanish) has seeped up from the ground in this area for tens of thousands of years. The tar is often covered with water. Over many centuries, animals that came to drink the water fell in, sank in the tar, and were preserved as bones. The George C. Page Museum is dedicated to researching the tar pits and displaying specimens from the animals that died there.

This seepage has been happening for tens of thousands of years. From time to time, the asphalt would form a pool deep enough to trap animals, and the surface would be covered with layers of water, dust, and leaves. Animals would wander in to drink, become trapped, and eventually die. Predators would also enter to eat the trapped animals and become stuck.

As the bones of the dead animals sink into the asphalt, it soaks into them, turning them a dark-brown or black color. Lighter fractions of petroleum evaporate from the asphalt, leaving a more solid substance, which holds the bones. Apart from the dramatic fossils of large mammals, the asphalt also preserves very small "microfossils": wood and plant remnants, insects, dust, and even pollen grains.

Radiometric dating of preserved wood and bones has given an age of 38,000 years for the oldest known material from the La Brea seeps. They still ensnare organisms today.

The George C. Page Museum,' part of the Natural History Museum of Los Angeles County, was built next to the tar pits in Hancock Park on Wilshire Boulevard. It tells the story of the tar pits and presents specimens from them. Visitors can walk around the park and see the tar pits. On the grounds of the park are life-sized models of prehistoric animals in or near the tar pits.  Of more than a hundred pits, only Pit 91 is still regularly excavated by researchers. The museum encloses the pit and tourists can watch as it is excavated for two months each summer. Paleontologists supervise and direct the work of volunteers.

On February 18, 2009, George C. Page Museum formally announced the 2006 discovery of 16 fossil deposits which had been removed from the ground during the construction of an underground parking garage for the Los Angeles County Museum of Art next to the tar pits. Among the finds are bones of a saber-toothed cat, six dire wolves, bison, horses, a giant ground sloth, turtles snails, clams, millipedes, fish, gophers, and an American lion.  Also discovered is a near-intact mammoth skeleton, nicknamed Zed; the only pieces missing are a rear leg, a vertebra and the top of his skull, which was shaved off by construction equipment in preparation to build the parking structure.

These fossils were packaged at the construction site and removed to the museum so that construction could continue. Over twenty large accumulations of tar and specimens were taken to be separated.
Among the prehistoric species associated with the La Brea Tar Pits are mammoths, dire wolves, short-faced bears, ground sloths, and the state fossil of California, the saber-toothed cat, Only one human has ever been found, a partial skeleton of a woman, dated at approximately 9,000 BC. who was apparently a victim of a homicide based on skull crush evidence.

The park is known for producing myriad mammal fossils dating from the last Ice Age. While mammal fossils generate significant interest, other fossils, including fossilized insects and plants, and even pollen grains, are also valued. These fossils help define a picture of what is thought to have been a cooler, moister climate in the Los Angeles basin during the glacial age. Among these fossils are microfossils. Microfossils are retrieved from a matrix of asphalt and sandy clay by washing with a solvent to remove the petroleum, then picking through the remains under a high-powered lens.

Tar pits around the world are unusual in accumulating more predators than prey. The reason for this is unknown, but one theory is that a large prey animal (say, a mastodon) would die or become stuck in a tar pit, attracting predators across long distances. This predator trap would catch predators along with their prey. Another theory is that dire wolves and their prey may have been trapped during a hunt. Since modern wolves hunt in packs, each prey animal could take several wolves with it.

To walk around the park and view the pits are free but to visit the museum is $7.