Editor's note: Last in a series on the Fairmead Fossil Center
I stand next to Blake Bufford, director of Fairmead Fossil Center, in a depression about 20 to 30 feet below the natural contours of the ground. We are in a landfill owned by Madera County and operated by Red Rock Environmental Group.
A paddle scraper starts at one end of the dirt patch, lowers its blade so that it will scrape away dirt to about 3 inches, and then moves in a straight line down the field. We watch in silence as it passes by. The driver waves and then leaves with a load of dirt. We begin walking.
Technically, what we are looking for are not fossils. We are looking for very old bones and bone fragments. What we find, though, on this first scrape, are rocks and caliche, a calcium carbonate formed when a cavity in the dirt is filled with minerals. Caliche is bone-colored, so it is easy for an amateur like me to mistake it for something important.
"Do you ever get a little bored?" I asked.
"No," Bufford said. He finds a rock and holds it aloft. "See this rock. It's quartzite. It began as quartz, then weathered into sand, then was compressed again and hardened into quartzite. Imagine how many millions of years it took to make this rock. I think about things like that when I'm out here.
"Humans are just a blip," he said. "Nothing more than a blip compared to this rock."
The site, though, is not known for its rocks. It's known for its Columbian mammoths, short-faced bears and saber-toothed cats. A tetrameryx, an extinct antelope, found its way here and then died. Bufford knows of only one other tetrameryx in California, in the Fremont area.
From the uncovered bones in Fairmead, scientists have been able to determine that some antelope had a much wider grazing range than previously thought, and they've been able to confirm theories about the plants that grew in this part of the Central Valley 500,000 years ago.
I ask Bufford how he acquired his expertise.
"It's mostly on-the-job training," he says. "See this? This is chiastolite. You can tell it by the cylindrical shape, and it will always have a little cross." He shows me the black rock with the cross inclusion.
He began volunteering at the Fairmead Center around 1996, about three years after a landfill worker discovered a mammoth tusk not far from where we stand, but he has been hunting fossils and archaeological artifacts his entire life.
When he was a kid, his father brought home an Indian stone mortar and pestle one day, and Bufford has been hooked on finding old stuff ever since.
"I was fascinated with that mortar and pestle," he tells me as we walk along, searching in the clay and sand for remnants of extinct mammals. "I used them to grind grapes and stuff."
Then he began searching the Fresno River for arrowheads. Now he regrets having displaced so many artifacts during his younger years. "I'd never pick up stuff like that today," he said.
The tractor is doing its last scrape for the morning, and we have not found any bones. Then I spot something. I see that it is not caliche. It's rounded and about 4 inches long.
"Is that a bone?" I asked.
Bufford bends down and uses his flat-head screwdriver to pry the object out of the clay.
"It is," he said, and he puts it in my hand.
"Are you sure?" I replied.
"Yeah, it is. Pretty good one, too," he said. "Maybe a horse or sloth. Could be a camel."
I look down at my hand. Humans did not migrate to North America until about 485,000 years after this animal died. For roughly 180,000,000 days, this bone has rested in the clay beneath my feet. I am the second person in the history of the universe to touch it, the first ever to see it.
I return the fragment to Bufford. I'd like to stay out here all day, looking for the remains of long-dead creatures. I understand now why he does not get bored. After all, he is helping to solve the mysteries of the past, one bone at a time.
Brigitte Bowers is a lecturer in the Merritt Writing Program at UC Merced.