For the past 50,000 years, crude oil has bubbled up from beneath the Los Angeles Basin and seeped to the surface of what are now called the La Brea Tar Pits. For these many millennia, molasses-thick asphaltum, colloquially called tar, has captured and preserved the region’s flora and hapless fauna. The pits—also a misnomer, for they are an artifact of nineteenth-century asphalt mining and twentieth-century fossil excavations—have yielded the most extensive record of a Pleistocene environment on the planet, a sticky and sedimentary time capsule that exists in one of the most populated metropolises in the United States.
Designated a National Natural Landmark in 1964, the tar pits are an invaluable scientific resource. They are—simultaneously—a public resource, an attraction in Hancock Park, which serves as a community green space in the midst of Mid-Wilshire’s “Miracle Mile,” a dense commercial and residential neighborhood of Los Angeles. When oilman G. Allan Hancock (for whom the park was named) donated his Rancho La Brea to Los Angeles in 1924, he stipulated that the county must juggle these interests, making use of the scientific marvels for research and exhibition while maintaining the land always as a public park. 
Initially, my research centered exclusively on efforts by the institution formerly known as the Los Angeles County Museum of History, Science, and Art to transform the tar pits into a Pleistocene Park or to create, at the very least, a Pleisto-scenic experience for Hancock Park visitors. They did this through the planting of flora that would have grown in Ice Age Los Angeles, extant in cooler and more humid parts of California, and the installation of statues depicting extinct fauna.
As I worked my way through the museum archives, paging through budgets, incident reports, and correspondence between residents and museum leadership, I found myself charmed by the ways in which diverse publics have laid claim to Hancock Park—its scientific marvels notwithstanding—and insisted that it accommodate their similarly diverse needs.
Though my research is chiefly archival, I have spent a fair bit of time wandering the park, observing as visitors to LACMA snap photos with the outdoor art installations, tallying the impressive number of dogs that one walker can wrangle, and watching as children try to toss whatever is at hand into the nearest seep, just to see if it sinks.
On one of these visits, I noticed a placard on the fence around Pit 13 warning visitors to “tread lightly,” as the “death traps” of La Brea continue their work. The tar “could take you down too, if you’re not careful,” the sign warned me. Visitors may take comfort in the fence on which this sign is posted, separating the death traps from the apparent safety of the paved walkways, though the asphalt is not confined to the fenced pits and seeps up throughout the park, in the parking lots, and into the basements of nearby apartment complexes. As Stephanie Le Menager has observed, the stuff of La Brea is “famous for literally sticking to its visitors, forcing the issue of its oozy embodiment.”
At once playful and foreboding, this call to “tread lightly,” evoking the ever-popular environmental impact metaphor of a footprint and anticipating human hubris, struck me as a powerful mode of public engagement. The threat of a truly immersive experience invited me to imagine, then to research:
What has happened in and on the banks of Pit 13?
Pit 13 was created in 1914, the thirteenth of 96 exploratory excavations dug during that decade. Paleontologists found it to contain a concentration of giant ground sloth bones along with the skulls of over 100 other mammals that met their end in the asphalt between 14,000 and 18,000 years ago.
Was it this pit where, in 1938, a truck driver staged a fake suicide in order to break an engagement? Or where a cocker spaniel “walked with history” and joined the “ghosts of giants” in 1951? Or where a park visitor in 1977 noticed an entrapped pigeon and wrote to recommend that the county cap the pit with mesh to prevent such modern tragedies? The pits are not always referred to by number and it is thus difficult to reconstruct the history of one particular excavation. There is, however, one archival reference to Pit 13 that captures perfectly the sticky relationship between the La Brea Tar Pits as a scientific exhibit and Hancock Park as a public space.
It was a June afternoon in 1950 and Hancock Park’s senior caretaker, Eugene Lipp, was patrolling the grounds when he noticed several visitors laying out drop cloths in front of Pit 13. The young army veteran arrived to find that out of these cloths had slithered three boa constrictors that were by that point sunning themselves in the grass. Lipp told his supervisor that he had thrown them out at once (“the people, not the snakes!”) despite protests that these animals were pets and there was “nothing improper” in their presence there. Moments later, a Boy Scout troop came along to peer into the pit, blissfully ignorant to the drama they just narrowly avoided. Whatever museum officials and their collaborators envisioned for the plein air Pleisto-scenes of Hancock Park, they could not entirely account for the ways in which the public would use and abuse the space.
What will happen in and on the banks of Pit 13?
I am a historian, not a prophet. But peering through the placard’s negative space (shaped like a squirrel to suggest the scale of creatures typically trapped today), I observed the sorts of things that park visitors were actively contributing to the future “fossil” record. A soccer ball, discarded pens, and an empty bottle from a medical marijuana dispensary littered the surface of Pit 13 on that cool January day, disrupting any Pleisto-scenic illusions. My prediction, then, is that Hancock Park’s publics will continue to interject into its exhibited ecologies, as they have always done.
 Hancock Park Deeds 1916, 1924. La Brea Tar Pits and Museum (1972-2009) Collection, Box 9. Natural History Museum of Los Angeles County Archives.
 Predictably, conversations among scientists, landscape architects, and artists about the display of native plants and animals—”Californians of ancient lineage” to quote one museum administrator—are inflected with broader social concerns. For more on resistance to non-human immigrants, see Jeannie N. Shinozuka’s “Deadly Perils: Japanese Beetles and the Pestilential Immigrant, 1920s–1930s,” American Quarterly 65, no. 4 (December, 2013): 831–52 and Peter Coates’ American Perceptions of Immigrant and Invasive Species: Strangers on the Land, Berkeley, CA: University of California Press, 2006. Quote from John A. Comstock, “A Glacial Botanic Garden,”Museum Patrons’ Association of the Los Angeles County Museum Quarterly, 1, no. 1 (January 1941), 13.
 Stephanie Le Menager, “Fossil, Fuel: Manifesto for the Post-Oil Museum,” Journal of American Studies 46, no. 2 (August 2012): 380.
 Early Excavations,” La Brea Tar Pits & Museum. Accessed December 31, 2018. https://tarpits.org/research-collections/history-rancho-la-brea/early-excavations.
 “Man in Tar Pit Rescued,” Los Angeles Times, May 6, 1936; “Dog Walks with Ghosts of Giants before Tar Pits Take Life Toll,” Los Angeles Times, June 25, 1951; Estherly Colton to Bernard Beck, circa August 11, 1977. Lee Arnold Collection (1975-1978), Box 5, Folder: Miscellaneous. Natural History Museum of Los Angeles County Archives.
 Eugene Lipp to Chester Stock, June 2, La Brea Tar Pits and Museum Box 11: Hancock Park, Folder: Development-Stock 1950. Natural History Museum of Los Angeles County Archives. While other constrictors of family Colubridae have been found in the pits, if Lipp’s identification was correct this was likely the first time that any Boa constrictor, family Boidae, had visited. See a list of the reptiles collected at Fish, Amphibian, and Reptile Fauna List, La Brea Tar Pits & Museum. Accessed December 31, 2018.
*Featured image credit: Fiberglass mammoth family sculpted by Howard Ball. Installed 1967-1968. Photo by author.